THERMOASSOCIATIVE AND EXCHANGEABLE COPOLYMERS, COMPOSITIONS
COMPRISING SAME
5 FIELD OF THE INVENTION
The invention relates to a composition resulting from mixing at least one copolymer A 1
resulting from the copolymerization of at least one monomer functionalized by diol functions and
at least one compound A2 comprising at least two boronic ester functions. They have very varied
rheological properties depending on the proportion of compounds A 1 and A2 used.
10 The field of the invention is that of associative and exchangeable polymers.
TECHNICAL BACKGROUND
High molecular weight polymers are widely used for increasing the viscosity of solutions in
numerous fields, such as the oil and paper industries, water treatment, the mining, cosmetics and
15 textile industries and generally in all the industrial techniques using thickened solutions.
Now, these high molecular weight polymers have the drawback of having a low permanent
shear strength with respect to the same polymers of smaller size. These shearing constraints on the
high molecular weight polymers lead to macromolecular chain cleavages. The polymer thus
degraded no longer has thickening properties, and the viscosity of the solutions containing it drops
20 irreversibly. This loss of permanent shear strength leads to a degradation of the properties of the
solutions based on high molecular weight polymers.
The Applicant set himself the objective of the formulation of novel additives which would
be more stable under shearing compared to the compounds of the prior art.
This objective is achieved thanks to novel additives which are associative and
25 exchangeable in a thermoreversible manner. The associated (potentially cross-linked) and
exchangeable copolymers of the invention have the advantage of being more stable to shear
stresses. This characteristic results from the combined use of two particular compounds, a
statistical copolymer bearing diol functions and a compound comprising at least two boronic ester
functions.
30 Polymers, of which at least one monomer comprises boronic ester functions are known
from document W02013147795. These polymers are used for the production of electronic devices,
in particular for devices in which it is desired to obtain a flexible user interface. These polymers are
also used as synthesis intermediates. They allow the functionalization of the polymers by coupling
with luminescent groups, electron-transporter groups, etc. The coupling of these groups is carried
35 out by standard organic chemistry reactions, involving the boron atom, such as for example Suzuki
coupling. However, no other use of these polymers, nor an association with other compounds is
envisaged.
A copolymer resulting from the copolymerization of a methyl methacrylate (MMA)
2
monomer and a glyceryl methacrylate monomer optionally protected by a boronic ester (namely
butyl boronic acid adduct of glyceryl methacrylate (BBA-GMA)) is known from document US
4,401,797. This copolymer forms a hydrogel in the presence of water and is used for the production
of contact lenses. However, no other use of this copolymer in the field of lubricating compositions,
5 nor an association via exchangeable chemical bonds with other compounds is envisaged.
Document EP0570073 discloses an additive which improves the viscosity index of a
lubricating composition in which it is added. This additive is a copolymer resulting from the
polymerization of 1-(methacryloylethoxy)-4,4,6-trimethyl-dioxaborinane and a methacrylate of a
linear (C12-C18) alkyl. This additive belongs to the family of the borate compounds which can be
10 represented by the general formula B(OR)3 with R an alkyl or aryl group. This additive does not
belong to the family of the boronate compounds which can be represented by the general formula
R-B(OR)2 with R an alkyl or aryl group. This additive cannot be associated with other compounds
via exchangeable chemical bonds.
The Applicant also set himself the objective of the synthesis of novel polymers making it
15 possible to increase the viscosity of solutions comprising them compared with the polymers of the
prior art. In particular, his objective is to provide novel rheological additives the behaviour of
which, when they are introduced into a solution, in particular into a hydrophobic solution, is
opposite as regards temperature change compared with the behaviour of the solution and the
polymer-type rheological additives of the prior art.
20 This objective is achieved thanks to novel rheological additives capable of associating, in
order to possibly form a gel, and exchanging chemical bonds in a thermoreversible manner. The
additives of the present invention have the advantage of increasing the viscosity of the solution
comprising them when the temperature increases.
Firstly, the Applicant attempted to synthesize copolymers bearing diol functions from
25 commercial compounds such as solketal methacrylate marketed by Sigma-Aldrich®.
However, the use of this monomer presents several drawbacks:
- its purchase price is high;
the polarity of the solketal methacrylate and 2,3-dihydroxypropyl methacrylate
units (resulting from the deprotection of the solketal function) limits the
30 solubility of the copolymers in apolar mediums;
the pendant diol function is difficult to access on the copolymers;
- depending on the nature of the copolymer, deprotection of the monomer once
polymerized can be difficult and/or lead to the formation of gels.
Thus, the Applicant also set himself the objective of the synthesis of novel statistical
35 copolymers bearing diol functions which overcome the drawbacks mentioned above.
This objective is achieved thanks to the novel polydiol statistical copolymers Al
comprising at least one monomer Ml of general formula (I) as described hereafter.
The polydiol statistical copolymers Al of the invention have in particular the following
3
advantages:
deprotection of the protected diol functions once polymerized is simpler due to
their greater accessibility;
they are more easily soluble in an apolar medium;
5 these polymers are adaptive, i.e. they are capable of responding to an external
stimulus by a change of properties;
they can associate and exchange in a thermoreversible manner with compounds
having at least two boronic ester functions, in particular in an apolar medium,
for example.
10 Secondly, the Applicant attempted to synthesize compounds bearing at least two boronic
ester functions from commercial compounds such as 4-vinylphenylboronic acid marketed by
Sigma-Aldrich®.
However, the use of this compound presents several drawbacks:
the polymerization of these monomers in a hydrophobic medium leads to the
15 formation of gels which are not compatible with the desired use;
the copolymers containing acid 4-vinylphenylboronic functions are not
temperature stable in a hydrophobic medium and lead to the formation of gels.
Thus, the Applicant also set himself the objective of the synthesis of novel compounds
bearing at least two boronic ester functions which overcome the drawbacks mentioned above.
20 This objective is achieved thanks to the novel compounds having at least two boronic ester
functions of general formula (III), or comprising at least one monomer M3 of general formula (IV),
as described hereafter.
The compounds of the invention having at least two boronic ester functions have in
particular the following advantages:
25 their syntheses are simple and inexpensive;
they are soluble in a hydrophobic medium, in particular in an apolar
hydrophobic medium;
they do not form a gel during polymerization;
they are temperature stable in a hydrophobic medium and do not lead to the
30 formation of gels.
SUMMARY OF THE INVENTION
Thus, a subject of the invention is a composition resulting from mixing at least:
o a statistical copolymer Al resulting from the copolymerization:
35 n of at least one first monomer M1 of general formula (I):
4
H2C
0
5
X10
OX2
10 (I)
in which:
- R1 is selected from the group formed by —H, —CH3, and —CH2-CH3;
- x is an integer ranging from 2 to 18;
- y is an integer equal to 0 or 1;
15 - X1 and X2, identical or different, are selected from the group formed by
hydrogen, tetrahydropyranyl, methyloxymethyl, ter-butyl, benzyl,
trimethylsilyl and t-butyl dimethylsilyl;
or
— X1 and X2 form with the oxygen atoms a bridge of the following formula
20
in which:
- the stars (*) symbolize the bonds to the oxygen atoms,
- R'2 and R"2, identical or different, are selected from the group
formed by hydrogen and a C1-C11 alkyl, preferably methyl;
— X1 and X2 form with the oxygen atoms a boronic ester of the following
formula
2
in which:
- the stars (*) symbolize the bonds to the oxygen atoms,
R"'2 is selected from the group formed by a C6-C18 aryl, a C7-
35 C18 aralkyl and C2-C18 alkyl, preferably a C6-C18 aryl;
n with at least one second monomer M2 of general formula (II):
25
or
30
5
H2C—
( R2
R3
5 in which:
R2 is selected from the group formed by —H, —CH3 and —CH2--CH3,
- R3 is selected from the group formed by a C6-C18 aryl, a C6-C18 aryl
substituted by an R'3, —O—R'3, —S—R'3 and —C(0)—N(H)—
R'3 group with R'3 a C1-C30 alkyl group; and
10 o a compound A2 comprising at least two boronic ester functions.
In a variant, the statistical copolymer Al results from the copolymerization of at least one
monomer Ml with at least two monomers M2 having different R3 groups.
Preferably, one of the monomers M2 has the general formula (II-A):
15
O
20 in which:
- R2 is selected from the group formed by —H, —CH3 and—CH2—CH3;
- R"3 is a C1-C14 alkyl group;
and the other monomer M2 has the general formula (II-B):
R"3
(II-A)
25 H2C
O
R" 3
(II-B)
30 in which:
- R2 is selected from the group formed by —H, —CH3 and —CH2—CH3;
- R"'3 is a C15-C30 alkyl group.
Preferably, the statistical copolymer Al described above comprises one or more of the
characteristics below, taken separately or in combination:
35
• the side chains of the copolymer have an average length ranging from 8 to 20
carbon atoms, preferably from 9 to 15 carbon atoms;
• the molar percentage of monomer M1 of formula (I) in said copolymer ranging
from 1 to 30%, preferably from 5 to 25%, more preferably ranging from 9 to
0
0 B-0
\ /
B—L
0
10
0
B—M
/ 0 X--(R.8)
30
R11
H2C
(IV)
6
21%;
• its number-average degree of polymerization ranges from 100 to 2000,
preferably from 150 to 1000;
• its polydispersity index (PDI) ranges from 1.05 to 3.75; preferably ranging from
5 1.10 to 3.45.
In a variant, the compound A2 is a compound of formula (III):
R6
in which:
15 - wi and w2, identical or different are integers selected between 0 and 1;
- R4, R5, R6 and R7, identical or different are selected from the group formed by
hydrogen and a hydrocarbon-containing group having from 1 to 24 carbon atoms,
preferably between 4 and 18 carbon atoms, preferably between 6 and 14 carbon
atoms;
20 - L is a divalent bond group and selected from the group formed by a C6-C18 aryl, a
C6-C18 aralkyl and a C2-C24 hydrocarbon-containing chain.
In another variant, the compound A2 is a statistical copolymer resulting from the
copolymerization:
• of at least one monomer M3 of formula (IV):
25
R10
in which:
— t is an integer equal to 0 or 1;
— u is an integer equal to 0 or 1;
35
— M and R8 are divalent bond groups, identical or different, selected from the
group formed by a C6-C18 aryl, a C,-C24 aralkyl and a C2-C24 alkyl, preferably a
C6-C18 aryl,
— X is a function selected from the group formed by —0—C(0)—, —C(0)-0—,
7
—C(0)—N(H)—, —N(H)—C(0)—, —S—, —N(H)—, —N(R'4)— and —0— with R'4 a
hydrocarbon-containing chain comprising from 1 to 15 carbon atoms;
- R9 is selected from the group formed by —H, —CH3 and—CH2—CH3;
— R10 and R11 identical or different are selected from the group formed by
5
hydrogen and a hydrocarbon-containing group having from 1 to 24 carbon
atoms, preferably between 4 and 18 carbon atoms, preferably between 6 and 14
carbon atoms;
n with at least one second monomer M4 of general formula (V):
R12
10
H2C
R13
(V)
in which:
- R12 is selected from the group formed by —H, —CH3 and —CH2—CH3,
15 - R13 is selected from the group formed by a C6-C18 aryl, a C6-C18 aryl
substituted by an R'135 —C(0)-0—R' 13; —0—R'13,
—S—R'13 and —C(0)—N(H)—R'13 group, with R'13 a C1-C28 alkyl group.
Preferably, the composition described above comprises one or more of the characteristics
below, taken separately or in combination:
20
• the chain formed by the sequence of the R10, M, X and (R8), groups with u
equal to 0 or 1 of the monomer of general formula (IV) has a total number of
carbon atoms ranging from 8 to 38, preferably from 10 to 26;
• the side chains of the copolymer A2 have an average length greater than or
equal to 8 carbon atoms, preferably ranging from 11 to 16 carbon atoms;
25
• the copolymer A2 has a molar percentage of monomer of formula (IV) in said
copolymer ranging from 0.25 to 20%, preferably from 1 to 10%;
• the copolymer A2 has a number-average degree of polymerization ranging from
50 to 1500, preferably from 80 to 800;
• the copolymer A2 has a polydispersity index (PDI) ranging from 1.04 to 3.54;
30 preferably ranging from 1.10 to 3.10;
• the content of copolymer Al in the composition ranges from 0.1% to 50% by
weight with respect to the total weight of the composition;
• the content of compound A2 in the composition ranges from 0.1% to 50% by
weight with respect to the total weight of the composition;
35
• the ratio by weight between the copolymer Al and the compound A2 (ratio
Al/A2) ranges from 0.005 to 200, preferably from 0.05 to 20, yet more
preferably from 0.1 to 10;
• the composition further comprises at least one additive selected from the group
8
formed by the polymers, pigments, dyes, fillers, plasticizers, fibres,
antioxidants, additives for lubricants, compatibilizing agents, anti-foaming
agents, dispersant additives, adhesion promoters and stabilizing agents.
5 BRIEF DESCRIPTION OF THE FIGURES
Figure 1 shows diagrammatically a statistical copolymer (P1), a gradient copolymer (P2)
and a block copolymer (P3); each circle shows a monomer unit. The difference in chemical
structure between the monomers is symbolized by a different colour (light grey/black).
Figure 2 shows diagrammatically a comb copolymer.
10
Figure 3 illustrates and shows diagrammatically the cross-linking of the composition
according to the invention in tetrahydrofuran (THF).
Figure 4 shows diagrammatically the behaviour of the composition of the invention as a
function of temperature. A statistical copolymer (2) having diol functions (function A) can
associate in a thermoreversible manner with a statistical copolymer (1) having boronic ester
15 functions (function B) via a transesterification reaction. The organic group of the boronic ester
functions (function B) which is exchanged during the transesterification reaction is a diol
symbolized by a black crescent. A chemical bond (3) of boronic ester type forms with release of a
diol compound.
Figure 5 shows the variation, for different temperatures comprised between 10°C and
20
110°C, of the viscosity (Pa.s, y-axis) as a function of the shear rate (s-I , x-axis) of a solution at 10%
by weight of a polydiol statistical copolymer A1-1 and 0.77% by weight of a diboronic ester
compound A2-1 in the group III base oil.
Figure 6A shows the change in the relative viscosity (without units, y-axis) as a function of
the temperature (°C, x-axis) of the compositions A, B-1, C-1 and D-1.
25
Figure 6B shows the change in the relative viscosity (without units, y-axis) as a function of
the temperature (°C, x-axis) of the compositions A, B-2, C-2 and D-2.
Figure 6C shows the change in the relative viscosity (without units, y-axis) as a function of
the temperature (°C, x-axis) of the compositions A, B-3 and C-3.
Figure 6D shows the change in the relative viscosity (without units, y-axis) as a function of
30 the temperature (°C, x-axis) of the compositions A, B-4, C-4 and D-4.
Figure 7 shows the variation, for different temperatures comprised between 10°C and
110°C, in the viscosity (Pa.s, y-axis) as a function of the shear rate (s-1, x-axis) of the composition
E.
Figure 8 shows the change in the relative viscosity (without units, y-axis) as a function of
35 the temperature (°C, x-axis) of the compositions A, B, C, D and E.
Figure 9 shows diagrammatically the exchange reactions of boronic ester bonds between
two polydiol statistical polymers (A1-1 and A1-2) and two boronic ester statistical polymers (A2-1
and A2-2) in the presence of diols.
9
Figure 10 shows the change in the relative viscosity (without units, y-axis) as a function of
the temperature (°C, x-axis) of the compositions F and G.
DESCRIPTION OF EMBODIMENTS OF THE INVENTION
5
A subject of the present invention is a composition of compounds which are associative and
exchangeable in a thermoreversible manner, this composition resulting from mixing at least:
— a polydiol statistical copolymer Al as described hereafter or in particular capable of
being obtained by one of the processes described hereafter;
10 — a compound A2 comprising at least two boronic ester functions.
o Polvdiol statistical copolymers (statistical copolymers Al)
The polydiol statistical copolymer (A 1) according to the present invention results from the
copolymerization of at least one first monomer MI bearing diol functions and at least one second
15 monomer M2, of different chemical structure to that of the monomer Ml.
By "copolymer", is meant an oligomer or a linear or branched macromolecule having a
sequence constituted by several repetitive units (or monomer unit) at least two units of which have
a different chemical structure.
By "monomer unit" or "monomer", is meant a molecule capable of being converted to an
20 oligomer or a macromolecule by association with itself or with other molecules of the same type. A
monomer denotes the smallest constitutive unit the repetition of which leads to an oligomer or to a
macromolecule.
By "statistical copolymer", is meant an oligomer or a macromolecule in which the
sequential distribution of the monomer units obeys known statistical laws. For example, a
25 copolymer is said to be statistical when it is constituted by monomer units the distribution of which
is a Markovian distribution. A diagrammatic statistical polymer (P1) is shown in Figure 1. The
distribution in the polymer chain of the monomer units depends on the reactivity of the
polymerizable functions of the monomers and on the relative concentration of the monomers. The
polydiol statistical copolymers of the invention are distinguished from the block copolymers and
30 from the gradient copolymers. By "block" is meant a part of a copolymer comprising several
identical or different monomer units which has at least one feature of its constitution or
configuration making it possible to distinguish it from its adjacent parts. A diagrammatic block
copolymer (P3) is shown in Figure 1. A gradient copolymer denotes a copolymer of at least two
monomer units of different structures the monomer composition of which changes in a gradual
35 fashion along the polymer chain, thus passing progressively from one end of the polymer chain rich
in one monomer unit, to the other end rich in the other comonomer. A diagrammatic gradient
polymer (P2) is shown in Figure 1.
By "copolymerization", is meant a process which allows a mixture of at least two monomer
10
units of different chemical structures to be converted to an oligomer or to a copolymer.
In the remainder of the present application, "B" represents a boron atom.
By "ci-c, alkyl" is meant a saturated, linear or branched hydrocarbon-containing chain
comprising from i to j carbon atoms. For example, by "C1-C10 alkyl", is meant a saturated, linear or
5 branched, hydrocarbon-containing chain comprising from 1 to 10 carbon atoms.
By "C6-C18 aryl", is meant a functional group which derives from an aromatic
hydrocarbon-containing compound comprising from 6 to 18 carbon atoms. This functional group
can be monocyclic or polycyclic. By way of illustration, a C6-C18 aryl can be phenyl, naphthalene,
anthracene, phenanthrene and tetracene.
10 By "C2-C10" alkenyl, is meant a linear or branched hydrocarbon-containing chain
comprising at least one unsaturation, preferably a carbon-carbon double bond, and comprising from
2 to 10 carbon atoms.
By "C7-C18 aralkyl", is meant an aromatic hydrocarbon-containing compound, preferably
monocyclic, substituted by at least one linear or branched alkyl chain and of which the total
15 number of carbon atoms of the aromatic ring and of its substituents ranges from 7 to 18 carbon
atoms. By way of illustration a C7-C18 aralkyl can be selected from the group formed by benzyl,
tolyl and xylyl.
By "C6-C18 aryl group substituted by an R'3 group", is meant an aromatic hydrocarboncontaining
compound, preferably monocyclic, comprising from 6 to 18 carbon atoms of which at
20 least one carbon atom of the aromatic ring is substituted by an R'3 group.
By "Hal" or "halogen" is meant a halogen atom selected from the group formed by
chlorine, bromine, fluorine and iodine.
• Monomer Ml
25 The first monomer M1 of the polydiol statistical copolymer (A 1 ) of the invention has the
general formula (I):
30
35
H2C
Xi 0
OX2
(I)
in which:
— R1 is selected from the group formed by —H, —CH3 and —CH2-CH3, preferably —H and
11
—CH3;
— x is an integer ranging from 2 to 18; preferably from 3 to 8; more preferably x is equal to
4;
— y is an integer equal to 0 or 1; preferably y is equal to 0;
5
— X1 and X2, identical or different, are selected from the group formed by hydrogen,
tetrahydropyranyl, methyloxymethyl, ter-butyl, benzyl, trimethylsilyl and t-butyl
dimethylsilyl;
or
10
— X1 and X2 form with the oxygen atoms a bridge of the following formula:
R" 2
in which:
- the stars (*) symbolize the bonds to the oxygen atoms,
15
- R'2 and R"2, identical or different, are selected from the group formed
by hydrogen and a C1-C„ alkyl group;
or
— X1 and X2 form with the oxygen atoms a boronic ester of the following formula:
20
B/R"'2
in which:
- the stars (*) symbolize the bonds to the oxygen atoms,
R"'2 is selected from the group formed by a C6-C18 aryl, a C,-C18
25
aralkyl and a C2-C18 alkyl, preferably a C6-C18 aryl, more preferably
phenyl.
Preferably, when R'2 and R"2 is a C1-C11 alkyl group; the hydrocarbon-containing chain is
a linear chain. Preferably, the C1-C11 alkyl group is selected from the group formed by methyl,
ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decycl and n-undecyl.
30 More preferably, the C1-C11 alkyl group is methyl.
Preferably, when R"'2 is a C2-C18 alkyl group; the hydrocarbon-containing chain is a linear
chain.
Among the monomers of formula (I), the monomers corresponding to formula (I-A) form
part of those preferred:
35
12
5
H2C
HO
OH
10 (I-A)
in which:
— R1 is selected from the group formed by —H, —CH3 and —CH2-CH3, preferably —H and
—CH3;
— x is an integer ranging from 2 to 18; preferably from 3 to 8; more preferably x is equal to
15 4;
— y is an integer equal to 0 or 1; preferably y is equal to 0.
Among the monomers of formula (I), the monomers corresponding to formula (I-B) form
part of those preferred: Ri
20
H2C
Y.,0
0
25
0Y2
(I-B)
in which:
— R1 is selected from the group formed by —H, —CH3 and —CH2-CH3, preferably —H and
30 —CH3;
— x is an integer ranging from 2 to 18; preferably from 3 to 8; more preferably x is equal to
4;
— y is an integer equal to 0 or 1; preferably y is equal to 0;
— Y1 and Y2, identical or different, are selected from the group formed by
35 tetrahydropyranyl, methyloxymethyl, ter-butyl, benzyl, trimethylsilyl and t-butyl
dimethylsilyl;
or
13
— Y1 and Y2 form with the oxygen atoms a bridge of the following formula:
5
in which:
- the stars (*) symbolize the bonds to the oxygen atoms,
- R'2 and R"2, identical or different, are selected from the group formed
by hydrogen and a C1-C11 alkyl group;
10 or
— Y1 and Y2 form with the oxygen atoms a boronic ester of the following formula:
15 in which:
the stars (*) symbolize the bonds to the oxygen atoms,
R'"2 is selected from the group formed by a C6-C18 aryl, a C7-C18
aralkyl and a C2-C18 alkyl, preferably a C6-C18 aryl, more preferably
phenyl.
20 Preferably, when R'2 and R"2 is a C1-C11 alkyl group; the hydrocarbon-containing chain is
a linear chain. Preferably, the C1-C11 alkyl group is selected from the group formed by methyl,
ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decycl and n-undecyl.
More preferably, the C1-C11 alkyl group is methyl.
Preferably, when R"'2 is a C2-C18 alkyl group; the hydrocarbon-containing chain is a linear
25 chain.
• Obtaining the monomer MI
The monomer Ml of general formula (I-A) is obtained by deprotection of the alcohol
functions of the monomer of general formula (I-B) according to the reaction diagram 1 below:
30
H2C
35
HO
OH
(I-A)
0Y2
10 HO
Y-10
0Y2
15
(I-b)
H2C
H2C
0
Y10
(I-B) 0Y2
35
protection
Diagram 3
HO
HO
OH
(I-a)
HO
Yi0
0Y2
(I-b)
14
Diagram 1
with R1, Y1, Y2, x and y as defined in the general formula (I-B) described above.
The deprotection reaction of the diol functions of the monomer of general formula (I-B) is
well known to a person skilled in the art. He knows how to adapt the deprotection reaction
5 conditions as a function of the nature of the protective groups Y1 and Y2.
The monomer MI of general formula (I-B) can be obtained by a reaction of a compound of
general formula (I-c) with an alcohol compound of general formula (I-b) according to the reaction
diagram 2 below:
Diagram 2
in which:
20 Y3 is selected from the group formed by a halogen atom, preferably
chlorine, —OH and 0-C(0)-R' i with R'1 selected from the group formed by
—H, —CH3 and —CH2-CH3, preferably —H and —CH3;
R1, Y1 , Y2, x and y have the same meaning as that given in general formula
(I-B).
25 These coupling reactions are well known to a person skilled in the art.
The compound of general formula (I-c) is commercially available from the suppliers:
Sigma-Aldrich® and Alfa Aesar®.
The alcohol compound of general formula (I-b) is obtained from the corresponding polyol
of formula (I-a) by protection of the diol functions according to the following reaction diagram 3:
30
15
with x, y, Y1 and Y2 as defined in the general formula (I-B).
The protection reaction of the diol functions of the compound of general formula (I-a) is well
known to a person skilled in the art. He knows how to adapt the protection reaction conditions as a
function of the nature of the protective groups Y1 and Y2 used.
5
The polyol of general formula (I-a) is commercially available from the suppliers: Sigma-
Aldrich® and Alfa Aesar®.
• Monomer M2
The second monomer of the statistical copolymer of the invention has the general formula
H2C
R2
(
R3
in which:
15 — R2 is selected from the group formed by —H, —CH3 and —CH2—CH3, preferably —H and
—CH3;
- R3 is selected from the group formed by a C6-C18 aryl group, a C6-C18 aryl substituted by
an R'3, —C(0)-0—R'3; —0—R'3, —S—R'3 and —C(0)—N(H)—R'3 group with R'3 a C1-C30
alkyl group.
20 Preferably, R'3 is a C1-C30 alkyl group of which the hydrocarbon-containing chain is linear.
Preferably, R3 is selected from the group formed by a C6-C18 aryl group, preferably a C6
aryl, and —C(0)-0—R'3 with R'3 a C1-C30 alkyl group.
Among the monomers of formula (II), the monomers corresponding to formula (II-A) form
part of those preferred:
H2C
O
O
R" 3
(II-A)
30 in which:
- R2 is selected from the group formed by —H, —CH3 and —CH2—CH3, preferably —H and
—CH3;
- R"3 is a CI-CI,' alkyl group.
By "C1-C14 alkyl group", is meant a saturated, linear or branched hydrocarbon-containing
35 chain comprising from 1 to 14 carbon atoms. Preferably, the hydrocarbon-containing chain is
linear. Preferably, the hydrocarbon-containing chain comprises from 4 to 12 carbon atoms.
25
16
Among the monomers of formula (II), the monomers corresponding to formula (II-B) also
form part of those preferred:
5
H2C
0
0
(II-B)
in which:
10
— R2 is selected from the group formed by —H, —CH3 and —CH2—CH3, preferably —H and
—CH3;
— R'"3 is a C15-C30 alkyl group.
By "C15-C30 alkyl group", is meant a saturated, linear or branched hydrocarbon-containing
chain comprising from 15 to 30 carbon atoms. Preferably, the hydrocarbon-containing chain is
15 linear. Preferably, the hydrocarbon-containing chain comprises from 16 to 24 carbon atoms.
• Obtaining the monomer M2
The monomers of formula (II), (II-A) and, (II-B) are well known to a person skilled in the
art. They are marketed by Sigma-Aldrich® and TCI®.
20
• Preferred polydiol copolymers
In an embodiment, a preferred statistical copolymer results from the copolymerization of at
least:
— a first monomer Ml of general formula (I) as described previously;
25 — a second monomer M2 of formula (II) as described previously, in which R2 is —H
and R3 is a C6-C18 aryl group; preferably R3 is phenyl.
In another embodiment, a preferred statistical copolymer results from the copolymerization
of at least:
30 — a first monomer M1 of general formula (I) as described previously;
— a second monomer M2 of formula (II-A) as described previously; and
— a third monomer M2 of formula (II-B) as described previously.
According to this other embodiment, a preferred statistical copolymer results from the
copolymerization of at least:
35 — a first monomer M1 of general formula (I) as described previously;
— a second monomer M2 of formula (II-A) in which R2 is —CH3 and R"3 is a C4-C12
alkyl group, preferably a linear C4-C12 alkyl;
— a third monomer M2 of formula (II-B) in which R2 is —CH3 and R"'3 is a C16-C24
17
alkyl group, preferably a linear C16-C24 alkyl.
According to this embodiment, a preferred statistical copolymer results from the
copolymerization of at least:
— a first monomer M1 of general formula (I) as described previously;
5 — a second monomer M2 selected from the group formed by n-octyl methacrylate, ndecyl
methacrylate and n-dodecyl methacrylate;
— a third monomer M2 selected from the group formed by palmityl methacrylate,
stearyl methacrylate, arachidyl methacrylate and behenyl methacrylate.
10 • Process for obtaining the polydiol copolymers
A person skilled in the art is in a position to synthesize the polydiol statistical copolymers
Al by calling on his general knowledge.
The copolymerization can be initiated by bulk polymerization or in solution in an organic
solvent by compounds that generate free radicals. For example, the copolymers of the invention are
15 obtained by the processes known as radical polymerization, in particular controlled radical
copolymerization, such as the method called radical polymerization controlled by Reversible
Addition-Fragmentation Chain Transfer (RAFT) and the method called radical copolymerization
controlled by Atom Transfer Radical Polymerization (ARTP). Conventional radical polymerization
and telomerization can also be used for the preparation of the copolymers of the invention (Moad,
20 G.; Solomon, D. H., The Chemistry of Radical Polymerization. 2nd ed.; Elsevier Ltd: 2006; p 639;
Matyaszewski, K.; Davis, T. P. Handbook of Radical Polymerization; Wiley-Interscience:
Hoboken, 2002; p 936).
25 A process for the preparation of a statistical copolymer comprises at least one
polymerization step (a) in which at least the following are brought into contact:
i) a first monomer M1 of general formula (I):
30
35
H2C
X 0
OX2
in which:
(I)
18
- R1 is selected from the group formed by —H, —CH3, and—CH2-CH3;
- x is an integer ranging from 2 to 18;
- y is an integer equal to 0 or 1;
- X1 and X2, identical or different, are selected from the group formed by
5
hydrogen, tetrahydropyranyl, methyloxymethyl, ter-butyl, benzyl,
trimethylsilyl and t-butyl dimethylsilyl;
or
— X1 and X2 form with the oxygen atoms a bridge of the following formula
10
in which:
- the stars (*) symbolize the bonds to the oxygen atoms;
- R'2 and R"2, identical or different, are selected from the group
15
formed by hydrogen and a C1-C11 alkyl, preferably methyl;
or
— X1 and X2 form with the oxygen atoms a boronic ester of the following
formula
R'"2
20
in which:
- the stars (*) symbolize the bonds to the oxygen atoms;
- R'"2 is selected from the group formed by a C6-C18 aryl, a C7-
C18 aralkyl and C2-C18 alkyl, preferably a C6-C18 aryl;
25 ii) at least one second monomer M2 of general formula (II):
H2C
30 in which:
- R2 is selected from the group formed by —H, —CH3 and —CH2—CH3;
- R3 is selected from the group formed by a C6-C18 aryl, a C6-C18 aryl
substituted by an R'3, —C(0)-0—R'3; —O—R'3, —S—R'3 and —C(0)—N(H)—
R'3 group with R'3 a C1-C30 alkyl group;
35 iii) at least one source of free radicals.
In an embodiment, the process can comprise moreover iv) at least one chain-transfer agent.
By "a source of free radicals" is meant a chemical compound making it possible to
generate a chemical species having one or more electrons which are not paired in its outer shell. A
19
person skilled in the art can use any source of free radicals known per se and suitable for the
polymerization processes, in particular controlled radical polymerization. Among the sources of
free radicals, the following are preferred, by way of illustration: benzoyl peroxide, tert-butyl
peroxide, the diazo compounds such as azobisisobutyronitrile, the peroxygenated compounds such
5 as persulphates or hydrogen peroxide, the redox systems such as the oxidation of Fe2+, the
persulphates/sodium-metabisulphite mixtures, or ascorbic acid/hydrogen peroxide mixtures or also
the compounds which can be cleaved photochemically or by ionizing radiation, for example ultraviolet
rays or by beta or gamma radiation.
By "chain-transfer agent", is meant a compound the goal of which is to ensure
10 homogeneous growth of the macromolecular chains by transfer reactions which are reversible
between species during growth, i.e. polymer chains terminated by a carbon-containing radical, and
dormant species, i.e. polymer chains terminated by a transfer agent. This reversible transfer process
makes it possible to control the molecular masses of copolymers thus prepared. Preferably in the
process of the invention, the chain-transfer agent comprises a thiocarbonylthio group —S—C(=S)—.
15 By way of illustration of a chain-transfer agent, the dithioesters, trithiocarbonates, xanthates and
dithiocarbamates can be mentioned. A preferred transfer agent is cumyl dithiobenzoate or 2-cyano-
2-propyl benzodithioate.
By "chain-transfer agent", is also meant a compound the goal of which is to limit the
growth of the macromolecular chains during formation by the addition of monomer molecules and
20 to initiate new chains, which makes it possible to limit the final molecular masses, or even to
control them. Such a type of transfer agent is used in telomerization. A preferred transfer agent is
cysteamine.
The process for the preparation of a polydiol statistical copolymer can comprise:
at least one step of polymerization (a) as defined above, in which the monomers
25 MI and M2 are selected with X1 and X2 different from hydrogen, and moreover
at least one step of deprotection (b) of the diol functions of the copolymer
obtained at the end of step (a), so as to obtain a copolymer in which X I and X2
are identical and are a hydrogen atom.
In an embodiment, the polymerization step (a) comprises the bringing into contact of at least
30 one monomer MI with at least two monomers M2 having different R3 groups.
In this embodiment, one of the monomers M2 has the general formula (II-A):
R2
H 2 C
35
O
R"3
(II-A)
in which:
20
- R2 is selected from the group formed by —H, —CH3 and—CH2—CH3;
- R"3 is a C1-C14 alkyl group;
and the other monomer M2 has the general formula (II-B):
5 H2C
0
0
R"' 3
(II-B)
in which:
10 — R2 is selected from the group formed by —H, —CH3 and —CH2—CH3,;
- R'"3 is a C15-C30 alkyl group.
The preferences and definitions described for the general formulae (I), (I-A), (I-B), (II-A),
(II-B) also apply to the processes described above.
15 • Properties of the polvdiol copolymers Al
The polydiol statistical copolymers Al are comb copolymers.
By "comb copolymers", is meant a copolymer having a main chain (also called backbone)
and side chains. The side chains are pendant on both sides of the main chain. The length of each
side chain is less than the length of the main chain. Figure 2 diagrammatically shows a comb
20 polymer.
The copolymers Al have a backbone of polymerizable functions, in particular a backbone of
methacrylate functions, and a mixture of hydrocarbon-containing side chains substituted or not by
diol functions.
As the monomers of formula (I) and (II) have polymerizable functions of identical or
25 substantially identical reactivity, a copolymer is obtained the monomers of which, having diol
functions, are distributed statistically along the backbone of the copolymer with respect to the
monomers the alkyl chains of which are non-substituted by diol functions.
The polydiol statistical copolymers Al have the advantage of being sensitive to external
stimuli, such as the temperature, pressure, shear rate; this sensitivity being demonstrated by a
30 change in properties. In response to a stimulus, the spatial conformation of the copolymer chains is
modified and the diol functions are rendered more accessible or less accessible to the association
reactions capable of generating cross-linking, as well as to the exchange reactions. These
association and exchange processes are reversible. The copolymer Al is a thermosensitive
copolymer, i.e. it is sensitive to changes in temperature.
35 Advantageously, the side chains of the polydiol statistical copolymer Al have an average
length ranging from 8 to 20 carbon atoms, preferably from 9 to 15 carbon atoms. By "average
length of side chain" is meant the average length of the side chains of each monomer constituting
the copolymer. A person skilled in the art knows how to obtain this average length by appropriately
21
selecting the types and the ratio of monomers constituting the polydiol statistical copolymer. The
choice of this average chain length makes it possible to obtain a polymer which is soluble in a
hydrophobic medium, whatever the temperature at which the copolymer is dissolved. The
copolymer Al is therefore miscible in a hydrophobic medium. By "hydrophobic medium" is meant
5 a medium which has no or very little affinity for water, i.e. it is not miscible in water or in an
aqueous medium.
Advantageously, the polydiol statistical copolymer Al has a molar percentage of monomer
M1 of formula (I) in said copolymer ranging from 1 to 30%, preferably 5 to 25%, more preferably
ranging from 9 to 21%.
10
In a preferred embodiment, the polydiol statistical copolymer A 1 has a molar percentage of
monomer M1 of formula (I) in said copolymer ranging from 1 to 30%, preferably 5 to 25%, more
preferably ranging from 9 to 21%, a molar percentage of monomer M2 of formula (II-A) ranging
from 8 to 92% and a molar percentage of monomer M2 of formula (II-B) ranging from 0.1 to 62%.
The molar percentage of monomers in the copolymer results directly from adjustment of the
15 quantities of monomers utilized for the synthesis of the copolymer.
In a preferred embodiment, the polydiol statistical copolymer Al has a molar percentage of
monomer M1 of formula (I) in said copolymer ranging from 1 to 30%, a molar percentage of
monomer M2 of formula (II-A) ranging from 8 to 62% and a molar percentage of monomer M2 of
formula (II-B) ranging from 8 to 91%. The molar percentage of monomers in the copolymer results
20 directly from adjustment of the quantities of monomers utilized for the synthesis of the copolymer.
Advantageously, the polydiol statistical copolymer Al has a number-average degree of
polymerization ranging from 100 to 2000, preferably from 150 to 1000. The degree of
polymerization is controlled in a known way by using a controlled radical polymerization
technique, a telomerization technique, or by adjusting the source quantity of free radicals when the
25 copolymers of the invention are prepared by conventional radical polymerization.
Advantageously, the polydiol statistical copolymer Al has a polydispersity index (PDI)
ranging from 1.05 to 3.75; preferably ranging from 1.10 to 3.45. The polydispersity index is
obtained by steric exclusion chromatography measurement using a polystyrene calibration.
Advantageously, the polydiol statistical copolymer Al has a number-average molar mass
30 ranging from 10,000 to 400,000 g/mol, preferably from 25,000 to 150,000 g/mol, the numberaverage
molar mass being obtained by steric exclusion chromatography measurement using a
polystyrene calibration.
The method of steric exclusion chromatography measurement using a polystyrene calibration
is described in the work (Fontanille, M.; Gnanou, Y., Chimie et physico-chimie des polymeres. 2nd
35 ed.; Dunod: 2010; p 546).
• Compound A2 diboronic ester
In an embodiment of the composition of the invention, the compound A2 comprising two
22
5
boronic ester functions has the general formula (III):
R6
0 R7
0 B—O
\ /
B—L
0
10 in which:
- w1 and w2, identical or different, are integers selected between 0 and 1,
R4, R5, R6 and R7, identical or different, are selected from the group formed by
hydrogen and a hydrocarbon-containing group having from 1 to 24 carbon atoms,
preferably from 4 to 18 carbon atoms, preferably from 6 to 14 carbon atoms;
15 - L is a divalent bond group and selected from the group formed by a C6-C18 aryl, a
C7-c24 aralkyl and a C2-C24 hydrocarbon-containing chain, preferably a C6-C18 aryl.
By "hydrocarbon-containing group having from 1 to 24 carbon atoms" is meant a linear or
branched alkyl or alkenyl group, having from 1 to 24 carbon atoms. Preferably, the hydrocarboncontaining
group comprises from 4 to 18 carbon atoms, preferably from 6 to 14 carbon atoms.
20 Preferably, the hydrocarbon-containing group is a linear alkyl.
By "C2-C24 hydrocarbon-containing chain" is meant a linear or branched alkyl or alkenyl
group, comprising from 2 to 24 carbon atoms. Preferably, the hydrocarbon-containing chain is a
linear alkyl group. Preferably the hydrocarbon-containing chain comprises from 6 to 16 carbon
atoms.
25
In an embodiment of the invention, the compound A2 is a compound of general formula
(III) above in which:
- w1 and w2, identical or different, are integers selected between 0 and 1;
— R4 and R6 are identical and are hydrogen atoms;
- R5 and R7 are identical and are a hydrocarbon-containing group, preferably a linear
30
alkyl, having from 1 to 24 carbon atoms, preferably from 4 to 18 carbon atoms,
preferably from 6 to 16 carbon atoms;
- L is a divalent bond group and is a C6-C18 aryl, preferably phenyl.
The boronic diester compound A2 of formula (III) as described above is obtained by a
condensation reaction between a boronic acid of general formula (III-a) and diol functions of the
35 compounds of general formula (III-b) and (III-c) according to the reaction diagram 4 below:
R7
Acetone, H2O
MgSO4
OH OH (Ill-b)
R5
0
0 B-0
\ /
B—L
0
(III)
HO L OH
I I +
5 OH OH
(11I-a)
23
Diagram 4
10 with w1, w2, L, R4, R5, R6 and R7, as defined above.
Indeed, by condensation of the boronic acid functions of the compound (III-a) with diol
functions of the compounds of formula (III-b) and of formula (III-c), compounds having two
boronic ester functions are obtained (compound of formula (III)). This step is carried out according
to means well known to a person skilled in the art.
15
Within the context of the present invention, the compound of general formula (III-a) is
dissolved, in the presence of water, in a polar solvent such as acetone. The presence of water
allows the chemical equilibria between the molecules of boronic acid of formula (III-a) and the
boroxine molecules obtained from the boronic acids of formula (III-a) to be shifted. Indeed, it is
well known that the boronic acids can spontaneously form boroxine molecules at ambient
20 temperature. Now, the presence of boroxine molecules is undesirable within the context of the
present invention.
The condensation reaction is carried out in the presence of a dehydration agent such as
magnesium sulphate. This agent makes it possible to trap the water molecules initially introduced
as well as those that are released by the condensation between the compound of formula (III-a) and
25 the compound of formula (III-b) and between the compound of formula (III-a) and the compound
of formula (III-c).
In an embodiment, the compound (III-b) and the compound (III-c) are identical.
A person skilled in the art knows how to adapt the quantities of reagents of formula (III-b)
and/or (III-c) and of formula (III-a) in order to obtain the product of formula (III).
30
• Compound A2 boronic ester copolymer
In another embodiment of the composition of the invention, the compound A2 comprising at
least two boronic ester functions is a boronic ester statistical copolymer resulting from the
copolymerization of at least one monomer M3 of formula (IV) as described below with at least one
35 monomer M4 of formula (V) as described below.
3 Monomer M3 of formula (IV)
The monomer M3 of the boronic ester statistical copolymer compound A2 has the general
formula (IV) in which:
5 R11
B—M
0
/ X—(F28).
R9
H2C
0
(IV)
R1 0
24
in which:
- t is an integer equal to 0 or 1;
10 - u is an integer equal to 0 or 1;
- M and R8 are divalent bond groups, identical or different, and are selected from
the group formed by a C6-C18 aryl, a C7-C24 aralkyl and C2-C24 alkyl, preferably
a C6-C18 aryl,
- X is a function selected from the group formed by -0-C(0)-, -C(O)-O-,
15 -C(0)-N(H)-, -N(H)-C(0)-, -S-, -N(R'4)- and -0- with R'4 a
hydrocarbon-containing chain comprising from 1 to 15 carbon atoms;
- R9 is selected from the group formed by -H, -CH3 and -CH2-CH3; preferably
-H and -CH3;
- R10 and R11, identical or different, are selected from the group formed by
20
hydrogen and a hydrocarbon-containing chain having from 1 to 24 carbon
atoms, preferably between 4 and 18 carbon atoms, preferably between 6 and 12
carbon atoms;
By "C2-C24 alkyl" is meant a saturated, linear or branched hydrocarbon-containing chain
comprising from 2 to 24 carbon atoms. Preferably, the hydrocarbon-containing chain is linear.
25 Preferably the hydrocarbon-containing chain comprises from 6 to 16 carbon atoms.
By. "hydrocarbon-containing chain comprising from 1 to 15 carbon atoms" is meant a
linear or branched alkyl or alkenyl group, comprising from 1 to 15 carbon atoms. Preferably, the
hydrocarbon-containing chain is a linear alkyl group. Preferably, it comprises from 1 to 8 carbon
atoms.
30
By "hydrocarbon-containing chain comprising from 1 to 24 carbon atoms" is meant a
linear or branched alkyl or alkenyl group, comprising from 1 to 24 carbon atoms. Preferably, the
hydrocarbon-containing chain is a linear alkyl group. Preferably, it comprises from 4 to 18 carbon
atoms, preferably between 6 and 12 carbon atoms.
In an embodiment of the invention, the monomer M3 has the general formula (IV) in
35 which:
- t is an integer equal to 0 or 1;
- u is an integer equal to 0 or 1;
- M and R8 are divalent bond groups and are different, M is a C6-C18 aryl,
25
preferably phenyl, R8 is a C7-C24 aralkyl, preferably benzyl;
— X is a function selected from the group formed by —0—C(0)—, —C(0)-0--,
—C(0)—N(H)— and —0—, preferably —C(0)—O— or —0—C(0)—;
— R9 is selected from the group formed by —H, —CH3, preferably —H;
5 — R10 and R11 are different, one of the R10 or R11 groups is H and the other R10 or
R11 group is a hydrocarbon-containing chain, preferably a linear alkyl group,
having from 1 to 24 carbon atoms, preferably between 4 and 18 carbon atoms,
preferably between 6 and 12 carbon atoms.
10 3 Synthesis of the monomer M3 of formula (IV)
In all the diagrams shown below, unless stated otherwise, the variables R10, R11, M, u, t, X,
R8, R'4 and R9 have the same definition as in formula (IV) above.
The monomers M3 of formula (IV) are in particular obtained from a preparation process
15 comprising at least one step of condensation of a boronic acid of general formula (IV-f) with a diol
compound of general formula (IV-g) according to the reaction diagram 5 below:
CH2
Rio
20
Rio
R11 1) Acetone, 110 0
B—M
0
/ X—(R8
H2C/
M
B—OH
HO
OH OH
2) MgSO4
Ri I
(IV-f)
(IV-g)
(IV)
25
Diagram 5
In fact, by condensation of the boronic acid functions of the compound of formula (IV-f)
with diol functions of the compounds of formula (IV-g), a boronic ester compound of formula (IV)
is obtained. This step is carried out according to methods well known to a person skilled in the art.
30 Within the context of the present invention, the compound of general formula (IV-f) is
dissolved, in the presence of water, in a polar solvent such as acetone. The condensation reaction is
carried out in the presence of a dehydration agent, such as magnesium sulphate.
The compounds of formula (IV-g) are commercially available from the following suppliers:
Sigma-Aldrich®, Alfa Aesar® and TCI®.
35 The compound of formula (IV-f) is obtained directly from the compound of formula (IV-e)
by hydrolysis according to the following reaction diagram 6:
Rg
20
(IV-e)
0
B-M
/
0 Y4
(IV-c)
Y5--(ROu
H2C
(IV-d)
0
B-M
o
/ X-t
,
R8)u
H2C
26
R1
0
B-M
0
/ X-(18)u
H2O
CH2
(ROu
x
M
HO
B-OH
(IV-f)
5
Rg
HNC
(IV-e)
Diagram 6
with
10 - z an integer equal to 0 or 1;
- R12 is selected from the group formed by —H, —CH3 and —CH2-CH3;
- u, X, M, R8 and R9 as defined above.
The compound of formula (IV-e) is obtained by reaction of a compound of formula (IV-c)
with a compound of formula (IV-d) according to the following reaction diagram 7:
15
R12
R12
Diagram 7
with
25 - z, u, R12, M, R'4, R9 and Its as defined above;
and in this diagram when:
• X represents —0—C(0)—, then Y4 represents an alcohol function —OH or a halogen
atom, preferably chlorine or bromine and Y5 is a carboxylic acid function —C(0)-0H;
• X represents —C(0)-0—, then Y4 represents a carboxylic acid function —C(0)—OH and
30 Y5 is an alcohol function —OH or a halogen atom, and preferably chlorine or bromine;
• X represents —C(0)—N(H)—, then Y4 represents a carboxylic acid function—C(0)—OH
or a-C(0)—Hal function, and Y5 is an amine function NH2;
• X represents —N(H)—C(O)-, then Y4 represents an amine function NH2 and Y5 is a
carboxylic acid function —C(0)—OH or a—C(0)--Hal function;
35 • X represents —S—, then Y4 is a halogen atom and Y5 is a thiol function —SH or Y4 is a
thiol function —SH and Y5 is a halogen atom;
• X represents —N(H)—, then Y4 is a halogen atom and Y5 is an amine function —NH2 or
Y4 is an amine function —NH2 and Y5 is a halogen atom;
15
HO M AY
H 4
12 Acetone, H2O
MgSO4
27
• X represents —N(R'4)—, then Y4 is a halogen atom and Y5 is an amine
function -N(H)(R'4) or Y4 is an amine function —N(H)(R'4) and Y5 is a halogen atom;
• X represents —0—, then Y4 is a halogen atom and Y5 is an alcohol function
—OH or Y4 is an alcohol function —OH and Y5 is a halogen atom.
5 These esterification, etherification, thioetherification, alkylation or condensation reactions
between an amine function and a carboxylic acid function are well known to a person skilled in the
art. A person skilled in the art therefore knows how to select the reaction conditions depending on
the chemical nature of the Y1 and Y2 groups in order to obtain the compound of formula (IV-e).
The compounds of formula (IV-d) are commercially available from the suppliers: Sigma-
10 Aldrich®, TCI® and Acros Organics®.
The compound of formula (IV-c) is obtained by a condensation reaction between a boronic
acid of formula (IV-a) with at least one diol compound of formula (IV-b) according to the
following reaction diagram 8:
R12
(IV-a)
(IV-b)
(IV-c)
Diagram 8
20 with M, Y4, z and R12 as defined above,
Among the compounds of formula (IV-b), the one in which R12 is methyl and z=0 is
preferred.
The compounds of formula (IV-a) and (IV-b) are commercially available from the following
suppliers Sigma-Aldrich®, Alfa Aesar® and TCI®.
25
,/ Monomer M4 of general formula (V):
The monomer M4 of the boronic ester statistical copolymer compound A2 has the general
formula (V)
30 H C
R12
R13 (V)
in which:
- R12 is selected from the group formed by —H, —CH3 and —CH2—CH3,
preferably —H and —CH3;
35
- R13 is selected from the group formed by a C6-C18 aryl, a C6-C18 aryl
substituted by an R'13 group, —C(0)-0—R'13; —0—R'13, —S—R'13 and -C(0)—
N(H)—R'13 with R'13 a C1-C25 alkyl group.
By "C1-C25 alkyl group", is meant a saturated, linear or branched hydrocarbon-containing
28
chain comprising from 1 to 25 carbon atoms. Preferably, the hydrocarbon-containing chain is
linear.
By "C6-C18 aryl substituted by an R13 group" group, is meant an aromatic hydrocarboncontaining
compound comprising from 6 to 18 carbon atoms of which at least one carbon atom of
5 the aromatic ring is substituted by a C1-C25 alkyl group as defined above.
Preferably, R13 is selected from the group formed by a C5-C18 aryl, preferably a C6 aryl, and
—C(0)-0—R' 13 with R' 13 a C 1-C25 alkyl group.
Among the monomers of formula (V), the monomers corresponding to formula (V-A) form
10 part of those preferred:
H2C
O
O
15
IT 1 3
(V-A)
in which:
- R2 is selected from the group formed by —H, —CH3 and —CH2—CH3, preferably —
H and —CH3;
20
- R'13 a C1-C25 alkyl group, preferably a linear C 1-C 25 alkyl, yet more preferably a
linear C5-C15 alkyl.
V Obtaining the monomer M4:
The monomers of formulae (V) and (V-A) are well known to a person skilled in the art. They
25 are marketed by Sigma-Aldrich® and TCI®.
V Synthesis of the boronic ester statistical copolymer compound A2
A person skilled in the art is in a position to synthesize the boronic ester statistical
copolymers by calling on his general knowledge. The copolymerization can be initiated by bulk
30 polymerization or in solution in an organic solvent by compounds generating free radicals. For
example, the boronic ester statistical copolymers are obtained by the processes known as radical
copolymerization, in particular controlled radical polymerization, such as the method called
controlled radical copolymerization by Reversible Addition-Fragmentation Chain Transfer (RAFT)
and the method called controlled radical polymerization by Atom Transfer Radical Polymerization
35 (ARTP). Conventional radical polymerization and telomerization can also be used for the
preparation of the copolymers of the invention (Moad, G.; Solomon, D. H., The Chemistry of
Radical Polymerization. 2nd ed.; Elsevier Ltd: 2006; p 639; Matyaszewski, K.; Davis, T. P.
Handbook of Radical Polymerization; Wiley-Interscience: Hoboken, 2002; p 936).
(
R12
29
A process for the preparation of a boronic ester statistical copolymer comprises at least one
polymerization step (a) in which at least the following are brought into contact:
i) a first monomer M3 of general formula (IV):
5 R10
0
B—M
o
/ X—(R8)
R1 1
10
H2C
(IV)
in which:
— t is an integer equal to 0 or 1;
— u is an integer equal to 0 or 1;
15
— M and R8 are divalent bond groups, identical or different, and are selected from
the group formed by a C6-C18 aryl, a C7-C24 aralkyl and a C2-C24 alkyl,
preferably a C6-C18 aryl;
— X is a function selected from the group formed by —0—C(0)—, —C(0)-0—,
—C(0)—N(H)-, —N(H) —C(0)—, —S—, —N(R'4)— and —0— with R'4 a
20 hydrocarbon-containing chain comprising from 1 to 15 carbon atoms;
— R9 is selected from the group formed by —H, —CH3 and —CH2—CH3; preferably
—H;
— R10 and R11, identical or different, are selected from the group formed by
hydrogen and a hydrocarbon-containing chain having from 1 to 24 carbon
25 atoms, preferably between 4 and 18 carbon atoms, preferably between 6 and 12
carbon atoms;
ii) at least one second monomer M4 of general formula (V):
H2C
30
R13
(V)
in which:
- R12 is selected from the group formed by —H, —CH3 and —CH2—CH3,
preferably —H or —CH3;
35 - R13 is selected from the group formed by a C6-C19 aryl, a C6-C18 aryl
substituted by an R' 13, —C(0)-0—R'13; —0—R' 13, —S—R' 13 and —C(0)—N(H)—
R' 13 group with R'13 a C1-C25 alkyl group.
iii) at least one source of free radicals.
30
The process can comprise moreover iv) at least one chain-transfer agent.
The preferences and definitions described for the general formulae (IV) and (V) also apply
to the process.
The sources of radicals and the transfer agents are those that have been described for the
5 synthesis of polydiol statistical copolymers. The preferences described for the sources of radicals
and of the transfer agents also apply to this process.
3 Properties of the boronic ester statistical copolymer compounds A2
Advantageously, the chain formed by the sequence of the R10, M, (R8)u groups with u, an
10 integer equal to 0 or 1, and X of the monomer M3 of general formula (IV) has a total number of
carbon atoms ranging from 8 to 38, preferably ranging from 10 to 26.
Advantageously, the side chains of the boronic ester statistical copolymer have an average
length greater than 8 carbon atoms, preferably ranging from 11 to 16. This chain length makes it
possible to solubilize the boronic ester statistical copolymer in a hydrophobic medium. By
15 "average length of side chain" is meant the average length of the side chains of each monomer
constituting the copolymer. A person skilled in the art knows how to obtain this average length by
appropriately selecting the types and the ratio of monomers constituting the boronic ester statistical
copolymer.
Advantageously, the boronic ester statistical copolymer has a molar percentage of
20 monomer of formula (IV) in said copolymer ranging from 0.25 to 20%, preferably from 1 to 10%.
Advantageously, the boronic ester statistical copolymer has a molar percentage of
monomer of formula (IV) in said copolymer ranging from 0.25 to 20%, preferably from 1 to 10%
and a molar percentage of monomer of formula (V) in said copolymer ranging from 80 to 99.75%,
preferably from 90 to 99%.
25 Advantageously, the boronic ester statistical copolymer has a number-average degree of
polymerization ranging from 50 to 1500, preferably from 80 to 800.
Advantageously, the boronic ester statistical copolymer has a polydispersity index (PDI)
ranging from 1.04 to 3.54; preferably ranging from 1.10 to 3.10. These values are obtained by
steric exclusion chromatography using tetrahydrofuran as eluent and a polystyrene calibration.
30 Advantageously, the boronic ester statistical copolymer has a number-average molar mass
ranging from 10,000 to 200,000 g/mol preferably from 25,000 to 100,000 g/mol. These values are
obtained by steric exclusion chromatography using tetrahydrofuran as eluent and a polystyrene
calibration.
35 3 Characteristics of the novel compositions of the invention
The compositions of the invention resulting from the mixture of at least one polydiol
statistical copolymer Al as defined above and of at least one compound A2 as defined previously
have very varied rheological properties depending on the proportion of the compounds Al and A2
OH
B-0
0)
30
25 0
Bi
\ + 2
o
,R
OH
31
used.
The polydiol statistical copolymers Al and the compounds A2 as defined above have the
advantage of being associative and of exchanging chemical bonds in a thermoreversible manner, in
particular in a hydrophobic medium, in particular an apolar hydrophobic medium.
5 Under certain conditions, the polydiol statistical copolymers Al and the compounds A2 as
defined above can be cross-linked.
The polydiol statistical copolymers Al and the compounds A2 also have the advantage of
being exchangeable.
By "associative", is meant that covalent chemical bonds of boronic ester type are established
10 between the polydiol statistical copolymers Al and the compounds A2 comprising at least two
boronic ester functions. Figure 4 shows associative polymers. Depending on the functionality of the
polydiols Al and of the compounds A2 and depending on the composition of the mixtures, the
formation of the covalent bonds between the polydiols Al and the compounds A2 may or may not
lead to the formation of a three-dimensional polymeric network.
15 By "chemical bond", is meant a covalent chemical bond of boronic ester type.
By "exchangeable", is meant that the compounds are capable of exchanging chemical bonds
between each other without the total number of chemical functions being modified. The boronic
ester bonds of the compounds A2 as well as the boronic ester bonds formed by association of the
polydiol statistical copolymers Al and the compounds A2 can be exchanged with diol functions
20 present in the composition in order to form new boronic esters and new diol functions without the
total number of boronic ester functions and diol functions being affected. The chemical exchange
reaction (transesterification) is shown in the following reaction diagram 9:
35 Diagram 9
with:
- R a chemical group of the compound A2,
- the hatched circle symbolizes the remainder of the chemical structure of the compound A2,
32
- the cross-hatched rectangle symbolizes the remainder of the chemical structure of the
polydiol statistical copolymer Al.
The boronic ester bonds of the compounds A2 as well as the boronic ester bonds formed by
association of the polydiol statistical copolymers Al and the compounds A2 can also be exchanged
5 in order to form new boronic esters without the total number of boronic ester functions being
affected. This other process of exchange of chemical bonds is carried out by metathesis reaction,
via successive exchanges of boronic ester functions in the presence of diols; this process is shown
in Figure 9. The polydiol statistical copolymer A1-1, which was associated with the polymer A2-1,
has exchanged a boronic ester bond with the boronic ester statistical copolymer A2-2. The polydiol
10 statistical copolymer A1-2, which was associated with the polymer A2-2, has exchanged a boronic
ester bond with the boronic ester statistical copolymer A2-1; the total number of boronic ester
bonds in the composition being unchanged and equal to 4. The copolymer A1-1 is then associated
both with the polymer A2-1 and with the copolymer A2-2. The copolymer A1-2 is then associated
both with the copolymer A2-1 and with the copolymer A2-2.
15
Another process of exchange of chemical bonds is shown in Figure 9, in which it can be
observed that the polydiol statistical copolymer A1-1, which was associated with the polymer A2-
1, has exchanged two boronic ester bonds with the boronic ester statistical copolymer A2-2. The
polydiol statistical copolymer A1-2, which was in association with the polymer A2-2, has
exchanged two boronic ester bonds with the boronic ester statistical copolymer A2-1; the total
20 number of boronic ester bonds in the composition being unchanged and equal to 4. The copolymer
Al-1 is then associated with the polymer A2-2. The copolymer A1-2 is then associated with the
polymer A2-1. The copolymer A2-1 has been exchanged with the polymer A2-2.
By "cross-linked", is meant a copolymer in the form of a network obtained by the
25 establishment of bridges between the macromolecular chains of the copolymer. These chains,
linked together, are mainly distributed in the three spatial dimensions. A cross-linked copolymer
forms a three-dimensional network. In practice, the formation of a copolymer network is ensured
by a solubility test. It is possible to verify that a network of copolymers has been formed by placing
the copolymer network in a known solvent in order to dissolve the non-crosslinked copolymers of
30 the same chemical composition. If the copolymer swells instead of dissolving, a person skilled in
the art knows that a network has been formed. Figure 3 illustrates this solubility test.
By "cross-linkable" is meant a copolymer capable of being cross-linked.
By "cross-linked in a reversible manner" is meant a cross-linked copolymer the bridges of
which are formed by a reversible chemical reaction. The reversible chemical reaction can be shifted
35 in one direction or another, leading to a change in structure of the polymer network. The copolymer
can pass from an initial non cross-linked state to a cross-linked state (three-dimensional network of
copolymers) and from a cross-linked state to an initial non cross-linked state. Within the context of
the present invention, the bridges which form between the copolymer chains are labile. These
33
bridges can form or be exchanged thanks to a chemical reaction which is reversible. Within the
context of the present invention, the reversible chemical reaction is a transesterification reaction
between diol functions of a statistical copolymer (copolymer A1) and the boronic ester functions of
a cross-linking agent (compound A2). The bridges formed are bonds of the boronic ester type.
5 These boronic ester bonds are covalent and labile due to the reversibility of the transesterification
reaction.
By "cross-linked in a thermoreversible manner", is meant a copolymer which is crosslinked
due to a reversible reaction the shift of which in one direction or in the other direction is
controlled by the temperature. The thermoreversible cross-linking mechanism of the composition
10 of the invention is shown diagrammatically in Figure 4. Unexpectedly, the Applicant observed that
at low temperature, the polydiol copolymer Al (symbolized by the copolymer bearing the
functions A in Figure 4) is not, or only slightly, cross-linked by the boronic ester compounds A2
(symbolized by the compound bearing the functions B in Figure 4). When the temperature
increases, the diol functions of the copolymer Al react with the boronic ester functions of the
15 compound A2 by a transesterification reaction. The polydiol statistical copolymers Al and the
compounds A2 comprising at least two boronic ester functions then link together and can
exchange. Depending on the functionality of the polydiols Al and of the compounds A2 and
depending on the composition of the mixtures, a gel may form in the medium, in particular when
the medium is apolar. When the temperature reduces again, the boronic ester bonds between the
20 polydiol statistical copolymers Al and the compounds A2 break, and if applicable, the composition
loses its gel character.
The quantity of boronic ester bonds (or boronic ester links) that can be established between
the polydiol statistical copolymers Al and the compounds A2 is adjusted by a person skilled in the
art by means of an appropriate selection of the polydiol statistical copolymer A1, the compound A2
25 and the composition of the mixture.
Moreover, a person skilled in the art knows how to select the structure of the compound A2
as a function of the structure of the statistical copolymer Al. Preferably, when the statistical
copolymer Al comprises at least one monomer M1 in which y=1, then the compound A2 of
general formula (III) or the copolymer A2 comprising at least one monomer M3 of formula (IV) is
30 preferably selected with w1= 1, w2=1 and t=1, respectively.
Advantageously, the content of statistical copolymer Al in the composition ranges from
0.1% to 99.5% by weight with respect to the total weight of the composition, preferably ranges
from 0.25% to 80% by weight with respect to the total weight of the final composition, more
preferably from 1% to 50% by weight with respect to the total weight of the final composition.
35
Advantageously, the content of compound A2 in the composition ranges from 0.1% to
99.5% by weight with respect to the total weight of the composition, preferably ranges from 0.25%
to 80% by weight with respect to the total weight of the final composition, more preferably from
0.5% to 50% by weight with respect to the total weight of the final composition.
34
In an embodiment, the content of statistical copolymer A 1 in the composition ranges from
0.5 to 99.5% by weight with respect to the total weight of the composition and the content of
compound A2, in particular of the boronic ester statistical copolymer in the composition ranges
from 0.5% to 99.5% by weight with respect to the total weight of the composition.
5 Preferentially, the ratio by weight between the polydiol statistical compound Al and
compound A2 (ratio Al/A2) in the composition ranges from 0.005 to 200, preferably from 0.05 to
20, yet more preferably from 0.1 to 10.
In an embodiment, the composition of the invention comprises:
0.5% to 40% by weight, with respect to the total weight of the
10 composition, of a mixture of at least one polydiol statistical copolymer
Al as defined previously and at least one compound A2 as defined
previously, preferably the mixture comprising from 0.5% to 99.5% by
weight of the statistical copolymer A 1 with respect to the total weight of
the mixture and from 0.5% to 99.5% by weight of the compound A2, in
15 particular of the boronic ester statistical copolymer, with respect to the
total weight of the mixture;
- 60% to 99.5% by weight, with respect to the total weight of the
composition, of a hydrophobic medium.
In an embodiment, the composition of the invention essentially consists of:
20 0.5% to 40% by weight, with respect to the total weight of the
composition, of a mixture of at least one polydiol statistical copolymer
A 1 as defined previously and at least one compound A2 as defined
previously, preferably the mixture comprising from 0.5% to 99.5% by
weight of the statistical copolymer Al with respect to the total weight of
25 the mixture and from 0.5% to 99.5% by weight of the compound A2, in
particular of the boronic ester statistical copolymer, with respect to the
total weight of the mixture;
60% to 99.5% by weight, with respect to the total weight of the
composition, of a hydrophobic medium.
30 In an embodiment, the composition of the invention is presented in the form of a stock
composition. By "stock composition" is meant, a composition from which a person skilled in the
art can make working solutions by sampling a certain quantity of stock solution completed by
making up with a necessary quantity of diluent (solvent or other) in order to obtain a desired
concentration. A working composition is therefore obtained by dilution of a stock composition.
35 A hydrophobic medium can be a solvent, a mineral oil, a natural oil, a synthetic oil.
In an embodiment, the composition of the invention can comprise moreover at least one
additive selected from the group formed by the thermoplastics, elastomers, thermoplastic
elastomers, thermosetting polymers, pigments, dyes, fillers, plasticizers, fibres, antioxidants,
35
additives for lubricants, compatibilizing agents, anti-foaming agents, dispersant additives, adhesion
promoters and stabilizing agents.
3 Process for the preparation of the novel compositions of the invention
5 The novel compositions of the invention are prepared by means well known to a person
skilled in the art. For example, it is sufficient for a person skilled in the art in particular to:
sample a desired quantity of a solution comprising the polydiol statistical
copolymer Al as defined above;
sample a desired quantity of a solution comprising the compound A2 as defined
10 above;
- mix the two solutions sampled in order to obtain the composition of the
invention.
A person skilled in the art also knows how to adjust the different parameters of the
composition of the invention in order to obtain either a composition in which the polydiol statistical
15 copolymer Al and the compound A2, in particular the boronic ester statistical copolymer, are
associated or a composition in which the polydiol statistical copolymer Al and the compound A2,
in particular the boronic ester statistical copolymer, are cross-linked. For example, a person skilled
in the art knows how to adjust in particular:
- the molar percentage of monomer MI bearing diol functions in the polydiol
20 statistical copolymer Al;
the molar percentage of monomer M3 bearing the boronic ester functions in the
boronic ester statistical copolymer A2;
the average length of the side chains of the polydiol statistical copolymer A 1;
the average length of the side chains of the boronic ester statistical copolymer A2;
25 - the length of the monomer M3 of the boronic ester statistical copolymer A2;
the length of the boronic diester compound A2;
- the number-average degree of polymerization of the polydiol statistical copolymers
Al and of the boronic ester statistical copolymers A2;
the percentage by weight of the polydiol statistical copolymer A 1;
30 - the percentage by weight of the diboronic ester compound A2;
the percentage by weight of the boronic ester statistical copolymer A2;
- etc.
3 Use of the novel compositions of the invention
35 The compositions of the invention can be used in all the solutions the viscosity of which
varies as a function of temperature. The compositions of the invention make it possible to thicken a
fluid and to control its viscosity. The polydiol statistical copolymers A 1 , the compounds A2 and
the compositions can be used in fields as varied as improved oil recovery, the paper industry,
36
paints, food additives, cosmetic or pharmaceutical formulation.
For example, the compositions of the invention can be added to compositions for
lubricating mechanical parts. Indeed, the behaviour of the novel compositions of the invention
when they are introduced into a base oil, is inverse vis-à-vis temperature change compared with the
5 behaviour of the base oil and the polymer-type rheological additives of the prior art. Unlike the
base oil, which liquefies when the temperature increases, the compositions of the present invention
have the advantage of thickening when the temperature increases. The formation of reversible
covalent bonds makes it possible to increase (reversibly) the molar mass of the polymers and
therefore limits the drop in viscosity of the base oil at high temperatures. Advantageously, the
10 viscosity of the lubricating composition is therefore controlled and is less dependent on
temperature fluctuations.
EXAMPLES
The following examples illustrate the invention without limiting it.
15
1 Synthesis of polymethacrylate statistical copolymers Al bearing a diol function
o 1.1: Starting from a monomer bearing a diol function protected in ketal form
20 In an embodiment, the statistical copolymer Al of the invention is obtained according to the
following reaction diagram 10:
H
HO
OH
I. Protection of the diol function
1. Reaction with MAC
CI 0
0 0
1
11 3. Polymerization
Protected copolymers
111, 4. Deprotection
Polytalkyl methacrylate-co-alicyldiol methacrylate) copolymer
Diagram 10
25
37
1.1.1 Synthesis of the monomer M1 bearing a diol function protected in ketal form
The synthesis of a methacrylate monomer bearing a diol function protected in ketal form is
carried out in two steps (steps 1 and 2 of reaction diagram 10) according to the protocol below: ,
5 1st step:
42.1 g (314 mmol) of 1,2,6-hexane triol (1,2,6-HexTri) is introduced into a l-L flask. 5.88 g
of molecular sieve (4°A) is added followed by 570 mL of acetone. 5.01 g (26.3 mmol) of paratoluene-
sulphonic acid (pTSA) is then slowly added. The reaction medium is left under stirring for
24 hours at ambient temperature. 4.48 g (53.3 mmol) of NaHCO3 is then added. The reaction
10 medium is left under stirring for 3 hours at ambient temperature before being filtered. The filtrate is
then concentrated under vacuum by means of a rotary evaporator until a suspension of white
crystals is obtained. 500 mL of water is then added to this suspension. The solution thus obtained is
extracted with 4 x 300 mL of dichloromethane. The organic phases are combined and dried over
MgSO4. The solvent is then completely evaporated off under vacuum at 25°C by means of a rotary
15 evaporator.
2nd step:
The product thus obtained is then introduced into a 1-L flask surmounted by a dropping
funnel. The glassware used having been previously dried overnight in an oven thermostatically
controlled at 100°C. 500 mL of anhydrous dichloromethane is then introduced into the flask
20 followed by 36.8 g (364 mmol) of triethylamine. A solution of 39.0 g (373 mmol) of methacryloyl
chloride (MAC) in 50 mL of anhydrous dichloromethane is introduced into the dropping funnel.
The flask is then placed in an ice bath in order to lower the temperature of the reaction medium to
around 0°C. The methacryloyl chloride solution is then added dropwise under vigorous stirring.
Once the addition of the methacryloyl chloride is completed, the reaction medium is left under
25 stirring at 0°C for 1 hour, then at ambient temperature for 23 hours. The reaction medium is then
transferred into a 3-L Erlenmeyer flask and 1 L of dichloromethane is added. The organic phase is
then successively washed with 4 x 300 mL of water, 6 x 300 mL of a 0.5M aqueous solution of
hydrochloric acid, 6 x 300 mL of a saturated aqueous solution of NaHCO3 and again 4 x 300 mL
of water. The organic phase is dried over MgSO4, filtered then concentrated under vacuum using a
30 rotary evaporator in order to produce 64.9 g (yield of 85.3%) of protected diol monomer in the
form of a light yellow liquid the characteristics of which are as follows:
'H NMR (400 MHz, CDC13) 8: 6.02 (singlet, 1H), 5.47 (singlet, 1H), 4.08 (triplet, J = 6.8
Hz, 2H), 4.05-3.98 (multiplet, 1H), 3.96 (doublet of doublets, J = 6 Hz and J = 7.6 Hz, 1H), 3.43
(doublet of doublets, J = 7.2 Hz and J = 7.2 Hz, 1H), 1.86 (doublet of doublets, J = 1.2 Hz and J =
35 1.6 Hz, 3H), 1.69-1.33 (multiplet, 6H), 1.32 (singlet, 3H), 1.27 (singlet, 3H).
1.1.2 Synthesis of methacrvlate copolymers according to the invention bearing diol functions
38
The synthesis of the methacrylate copolymers bearing diol functions according to the
invention is carried out in two steps (steps 3 and 4 of reaction diagram 10):
- Copolymerization of two alkyl methacrylate monomers with a methacrylate
monomer bearing a diol function protected in ketal form;
5 - Deprotection of the copolymer.
More precisely, the synthesis of the copolymer is carried out according to the following
protocol:
10.5 g (31.0 mmol) of stearyl methacrylate (StMA), 4.76 g (18.7 mmol) of lauryl
10 methacrylate (LMA), 3.07 g (12.7 mmol) of methacrylate bearing a diol function protected in ketal
form obtained according to the protocol described in paragraph 1.1.1, 68.9 mg (0.253 mmol) of
cumyl dithiobenzoate and 19.5 mL of anisole are introduced into a 100-mL Schlenk tube. The
reaction medium is placed under stirring and 8.31 mg (0.0506 mmol) of azobisisobutyronitrile
(AIBN) in solution in 85 μ1, of anisole is introduced into the Schlenk tube. The reaction medium is
15 then degassed for 30 minutes by bubbling argon through it before being brought to 65°C for a
period of 16 hours. The Schlenk tube is placed in an ice bath in order to stop the polymerization,
then the polymer is isolated by precipitation from methanol, followed by filtration and drying under
vacuum at 30°C overnight.
A copolymer is thus obtained, having a number-average molar weight (Mn) of 41,000 g/mol,
20 a polydispersity index (PDI) of 1.22 and a number-average degree of polymerization (DPn) of 167.
These values are obtained respectively by steric exclusion chromatography using tetrahydrofuran
as eluent and a polystyrene calibration and by monitoring the conversion to monomers during the
copolymerization.
Deprotection of the copolymer is carried out according to the following protocol:
25 7.02 g of copolymer containing approximately 20% protected diol function obtained
previously is introduced into a 500-mL Erlenmeyer flask. 180 mL of dioxane is added and the
reaction medium is placed under stirring at 30°C. 3 mL of a 1M aqueous solution of hydrochloric
acid, then 2.5 mL of an aqueous solution of hydrochloric acid, 35% by weight, are added dropwise.
The reaction medium then becomes slightly opaque and 20 mL of THE is introduced in order to
30 make the medium completely homogeneous and transparent. The reaction medium is then left
under stirring at 40°C for 48 hours. The copolymer is recovered by precipitation from methanol,
filtration and drying under vacuum at 30°C overnight.
A poly(alkyl methacrylate-co-alkyldiol methacrylate) copolymer is obtained, containing
approximately 20 mol.% diol monomer units MI, and having an average pendant alkyl chain
35 length of 13.8 carbon atoms.
OH
,;. 1. Protection of the diol function
OH
2. Reaction with MAC
CI 0
39
o 1.2: Starting from a monomer bearing a diol function protected in boronic ester form
In another embodiment, the statistical copolymer Al of the invention is obtained according
to the following reaction diagram 11:
Polymerization
Protected copolymers
I
t 4. Deprotection
Poly(alkyl methacrylate-co-allcyldiol methacrylate) copolymers
5
Diagram 11
1.2.1 Synthesis of the monomer Ml bearing a diol function protected in boronic ester form
The synthesis of a methacrylate monomer bearing a diol function protected in ester form is
10 carried out in two steps (steps 1 and 2 of Diagram 11) according to the following protocol:
lst step:
6.01 g (49.3 mmol) of phenylboronic acid (PBA) and 300 mL of acetone are introduced
into a 500-mL beaker, followed by 1.5 mL of water. The reaction medium is placed under stirring
and 6.07 g (45.2 mmol) of 1,2,6-hexanetriol is added slowly. An excess of magnesium sulphate is
15 added to the reaction medium in order to trap the water initially introduced as well as the water
released by the condensation between the phenylboronic acid and the 1,2,6-hexanetriol. The
reaction medium is left under stirring at ambient temperature for 30 minutes before being filtered
then concentrated under vacuum by means of a rotary evaporator.
2nd step:
20
The light yellow liquid thus obtained in the preceding step is then introduced into a 1-L
flask surmounted by a dropping funnel. The glassware used having been pre-dried beforehand
overnight in an oven thermostatically controlled at 100°C. 90 mL of anhydrous dichloromethane is
40
then introduced into the flask followed by 6.92 g (68.4 mmol) of triethylamine. A solution of 5.82
g (55.7 mmol) of methacryloyl chloride (MAC) in 10 mL of anhydrous dichloromethane is
introduced into the dropping funnel. The flask is then placed in an ice bath in order to lower the
temperature of the reaction medium to around 0°C. The methacryloyl chloride solution is then
5 added dropwise under vigorous stirring. Once the addition of the methacryloyl chloride is
completed, the reaction medium is left under stirring at 0°C for 1 hour, then at ambient temperature
for 17 hours. The reaction medium is then transferred into a 500-mL Erlenmeyer flask and 300 mL
of dichloromethane is added. The organic phase is then successively washed with 4 x 100 mL of
water, 4 x 100 mL of a 0.1M aqueous solution of hydrochloric acid, 4 x 100 mL of a saturated
10 aqueous solution of NaHCO3 and again 4 x 100 mL of water. The organic phase is dried over
MgSO4, filtered then concentrated under vacuum using a rotary evaporator in order to produce 11.6
g (yield of 89%) of protected diol monomer in the form of a light yellow-coloured liquid the
characteristics of which are as follows:
1H NMR (400 MHz, CDC13) 8: 7.81 (doublet of doublets, J = 4 Hz and J = 8 Hz, 2H), 7.48
15 (triplet of triplets, J = 1.2 Hz and J = 7.2 Hz, 1H), 7.38 (triplet of triplets, J = 1.2 Hz and J = 6.8 Hz,
1 H), 6.10 (singlet, 1H), 5.55(singlet, 1H), 4.63-4.53 (multiplet, I H), 4.44 (doublet of doublets, J=
7.6 Hz and J = 8.8 Hz, 1H), 4.18 (triplet, J = 6.8 Hz, 2H), 3.95 (doublet of doublets, J = 6.8 Hz and
J = 8.8 Hz, 1H), 1.94 (doublet of doublets, J = 1.2 Hz and J = 1.6 Hz, 3H), 1.81-1.47 (multiplet,
6H)
20
1.2.2 Synthesis of methacrylate copolymers according to the invention bearing diol functions
The synthesis of the methacrylate copolymers bearing diol functions according to the
invention is carried out in two steps (steps 3 and 4 of Diagram 11):
- Copolymerization of two alkyl methacrylate monomers with a methacrylate
25 monomer bearing a diol function protected in boronic ester form;
- Deprotection of the copolymer.
The following procedures describe the synthesis of a poly(alkyl methacrylate-co-alkyldiol
methacrylate) copolymer containing approximately 10 mol.% of diol monomer units, and having
30 an average pendant alkyl chain length of 13.8 carbon atoms.
The synthesis of the polymer is carried out according to the following protocol:
13.5 g (40 mmol) of stearyl methacrylate (StMA), 12 g (47.2 mmol) of lauryl methacrylate
(LMA), 3.12 g (10.8 mmol) of methacrylate bearing a diol function protected in boronic ester form,
35 92.1 mg (0.416 mmol) of cumyl dithiobenzoate and 34 mL of anisole are introduced into a 100-mL
Schlenk tube. The reaction medium is placed under stirring and 13.7 mg (0.0833 mmol) of
azobisisobutyronitrile (AIBN) in solution in 135 !IL of anisole is introduced into the Schlenk tube.
The reaction medium is then degassed for 30 minutes by bubbling argon through it before being
41
brought to 65°C for a period of 24 hours. The Schlenk tube is placed in an ice bath in order to stop
the polymerization and 30 mL of tetrahydrofuran (THF) is then added to the reaction medium. The
polymer is isolated by precipitation from cold methanol, followed by filtration and drying under
vacuum at 30°C overnight.
5 A copolymer is thus obtained, having a number-average molar weight (Me) of 70,400 g/mol,
a polydispersity index (PDI) of 3.11 and a number-average degree of polymerization (DP„) of 228.
These values are obtained respectively by steric exclusion chromatography using tetrahydrofuran
as eluent and a polystyrene calibration and by monitoring the conversion to monomers during the
copolymerization.
10
Deprotection of the copolymer is carried out according to the following protocol:
19 g of copolymer obtained in the preceding step and containing approximately 10%
protected diol function is introduced into a 1-L Erlenmeyer flask. 250 mL of dichloromethane and
30 mL of an aqueous solution of hydrochloric acid are added. The reaction medium is stirred at
15 ambient temperature for 24 hours before being poured dropwise into 1 L of aqueous solution of
sodium hydroxide (pH = 10) then stirred at ambient temperature for another 24 hours. Throughout
this period of stirring, the reaction medium is composed of two phases. The organic phase is
recovered using a separating funnel and the polymer is precipitated from cold methanol. The
polymer thus obtained is re-dissolved in 100 ml of dichloromethane in order to be precipitated from
20 cold methanol again. The polymer is recovered and dried under vacuum at 30°C overnight.
A poly(alkyl methacrylate-co-alkyldiol methacrylate) copolymer is obtained containing
approximately 10 mol.% diol monomer units, and having an average pendant alkyl chain length of
13.8 carbon atoms.
25 2. Synthesis of the compounds A2 of the invention
o 2.1: Synthesis of a boronic diester as cross-linking agent
The synthesis of a compound A2 according to the invention is carried out according to the
following protocol and according to reaction diagram 12:
30
HO. ,OH
HO' 'OH
HO Oli
1...1kcetone. 1410
2.W°.
Diagram 12
42
1,4 Benzenediboronic acid (1,4-BDBA) (1.5 g; 9.05 mmol) is introduced into a 500-mL
beaker, followed by 300 mL of acetone. The reaction medium is placed under stirring and 0.300 g
(16.7 mmol) of water is introduced dropwise. The reaction medium then becomes transparent and
homogeneous and 1,2-dodecanediol (4.02 g; 19.9 mmol) is slowly added. After the latter is
5 completely dissolved, an excess of magnesium sulphate is added in order to trap the water
introduced initially as well as the water released by the condensation between the 1,4-BDBA and
the 1,2-dodecanediol. After 15 minutes under stirring, the reaction medium is filtered. The solvent
is then removed from the filtrate by means of a rotary evaporator, in order to produce 4.41 g of
boronic diester and 1,2-dodecanediol (yield of 98%) in the form of a white solid.
10 The characteristics are as follows:
IH NMR (400 MHz, CDCI3) Boronic diester: 8: 7.82 (singlet, 2H), 4.63-4.51 (multiplet,
2H), 4.42 (doublet of doublets, J = 8 Hz and J = 8.8 Hz, 2H), 3.95 (doublet of doublets, J = 7.2 Hz
and J = 8.8 Hz, 2H), 1.81-1.31 (multiplet, 36H), 0.88 (triplet, J = 7.2 Hz, 6H); 1,2-dodecanediol: 8:
3.85-3.25 (multiplet, approximately 2.17H), 1.81-1.31 (multiplet, approximately 13.02H), 0.88
15 (triplet, J = 7.2 Hz, approximately 2.17H)
o 2.2: Synthesis of the poly(alkyl methacylate-co-boronic ester monomer) copolymer
20 2.2.1 Synthesis of the boronic ester monomer
The boronic ester monomer of the invention is synthesized according to the following
reaction diagram 13:
COOH HO\_ _O(H
CH3
2.
H
CH3
25
9
HO"OH
gH
try-i0 9 CH3
CI
The monomer is obtained according to the two-step protocol:
30
The first step consists of synthesizing a boronic acid and the second step consists of
obtaining a boronic ester monomer.
lst step:
4-Carboxyphenylboronic acid (CPBA) (5.01 g; 30.2 mmol) is introduced into a 1-L beaker
followed by 350 mL of acetone and the reaction medium is placed under stirring. 7.90 mL (439
35 mmol) of water is added dropwise until the 4-carboxyphenylboronic acid is completely dissolved.
The reaction medium is then transparent and homogeneous. 1,2-Propanediol (2.78 g; 36.6 mmol) is
then slowly added, followed by an excess of magnesium sulphate in order to trap the water initially
introduced as well as the water released by the condensation between the CPBA and the 1,2-
43
propanediol. The reaction medium is left under stirring for 1 hour at 25°C before being filtered.
The solvent is then removed from the filtrate by means of a rotary evaporator. The product thus
obtained and 85 mL of DMSO are introduced into a 250-mL flask. The reaction medium is placed
under stirring then after complete homogenization of the reaction medium, 8.33 g (60.3 mmol) of
5 K2CO3 is added. 4-(Chloromethyl)styrene (3.34 g; 21.9 mmol) is then slowly introduced into the
flask. The reaction medium is then left under stirring at 50°C for 16 hours. The reaction medium is
transferred into a 2-L Erlenmeyer flask, then 900 mL of water is added. The aqueous phase is
extracted with 8 x 150 mL of ethyl acetate. The organic phases are combined, then extracted with 3
x 250 mL of water. The organic phase is dried over MgSO4 and filtered. The solvent is removed
10 from the filtrate by means of a rotary evaporator in order to produce the boronic acid monomer
(5.70 g; yield of 92.2%) in the form of a white powder, the characteristics of which are as follows:
Ili NMR (400 MHz, CDC13) 8: 7.98 (doublet, J = 5.6 Hz, 4H), 7.49 (doublet, J = 4 Hz, 4H),
6.77 (doublet of doublets, J = 10.8 Hz and J = 17.6 Hz, 1H), 5.83 (doublet of doublets,
J = 1.2 Hz and J = 17.6 Hz, 1H), 5.36 (singlet, 2H), 5.24 (doublet of doublets, J = 1.2 Hz and J =
15 11.2 Hz, 1H).
2"d step:
The boronic acid monomer (5.7 g; 20.2 mmol) obtained during the first step and 500 mL of
acetone are introduced into a 1-L Erlenmeyer flask. The reaction medium is placed under stirring
20 and 2.6 mL (144 mmol) of water is added dropwise until the boronic acid monomer is completely
dissolved. The reaction medium is then transparent and homogeneous. A solution of 1,2-
dodecanediol (5.32 g; 26.3 mmol) in 50 mL of acetone is slowly added to the reaction medium,
followed by an excess of magnesium sulphate in order to trap the water initially introduced as well
as the water released by the condensation between the boronic acid monomer and the 1,2-
25 dodecanediol. After 3 hours under stirring at ambient temperature, the reaction medium is filtered.
The solvent is then removed from the filtrate by means of a rotary evaporator in order to produce
10.2 g of a mixture of boronic ester monomer and 1,2-dodecanediol in the form of a light yellow
solid.
The characteristics are as follows:
30 `I-1 NMR (400 MHz, CDC13): Boronic ester monomer: 8: 8.06 (doublet, J = 8 Hz, 2H), 7.89
(doublet, J = 8 Hz, 2H), 7.51 (doublet, J = 4 Hz, 4H), 6.78 (doublet of doublets, J = 8 Hz and J = 16
Hz, 1H), 5.84 (doublet of doublets, J = 1.2 Hz and J = 17.6 Hz, 1H), 5.38 (singlet, 2H), 5.26
(doublet of doublets, J = 1.2 Hz and J = 11.2 Hz, 1H), 4.69-4.60 (multiplet, 1H), 4.49 (doublet of
doublets, J = 8 Hz and J = 9.2 Hz, 1H), 3.99 (doublet of doublets, J = 7.2 Hz and J = 9.2 Hz, 1H),
35 1.78-1.34 (multiplet, 18H), 0.87 (triplet, J = 6.4 Hz, 3H); 1,2-dodecanediol: 8: 3.61-3.30 (multiplet,
approximately 1.62H), 1.78-1.34 (multiplet, approximately 9.72H), 0.87 (triplet, J = 6.4 Hz,
approximately 1.62H)
44
In a variant of the synthesis, the boronic acid monomer obtained during the first step can be
protected by 1,2-propanediol instead of 1,2-dodecanediol, following the following procedure:
The boronic acid monomer (3.5 g; 12.4 mmol) obtained during the first step and 250 mL of
acetone are introduced into a 500-L Erlenmeyer flask. The reaction medium is placed under stirring
5 and 1.8 mL (100 mmol) of water is added dropwise until the boronic acid monomer is completely
dissolved. The reaction medium is then transparent and homogeneous. The 1,2-propanediol (1.08
g; 14.2 mmol) is slowly added to the reaction medium, followed by an excess of magnesium
sulphate in order to trap the water initially introduced as well as the water released by the
condensation between the boronic acid monomer and the 1,2-propanediol. After 2 hours under
10 stirring at ambient temperature, the reaction medium is filtered. The solvent is then removed from
the filtrate by means of a rotary evaporator in order to produce a mixture of boronic ester monomer
and 1,2-propanediol in the form of a light yellow solid.
The characteristics are as follows:
1H NMR (400 MHz, CDC13): Boronic ester monomer: 8: 8.06 (doublet, J = 8 Hz, 2H), 7.87
15 (doublet, J = 8 Hz, 2H), 7.42 (doublet, J = 2 Hz, 4H), 6.72 (doublet of doublets, J = 11 Hz and J =
18 Hz, 1H), 5.76 (doublet of doublets, J = 1 Hz and J = 18 Hz, 1H), 5.35 (singlet, 2H), 5.26
(doublet of doublets, J = 1 Hz and J = 11 Hz, 1H), 4.77-4.68 (multiplet, 1H), 4.48 (doublet of
doublets, J = 8 Hz and J = 9 Hz, 1H), 3.91 (doublet of doublets, J = 8 Hz and J = 9 Hz, 1H), 1.42
(doublet, J = 6Hz, 3H); 1,2-dodecanediol: 8: 3.66-3.37 (multiplet, approximately 0.26H), 1.17
20 (doublet, J = 6 Hz, approximately 0.39H)
2.2.2 Synthesis of compound A2, poly(alkyl methacrylate-co-boronic ester monomer) statistical
copolymer
The statistical copolymer A2 of the invention is obtained according to the following
25 protocol:
2.09 g of a previously prepared mixture of boronic ester monomer and 1,2-dodecanediol
(containing 3.78 mmol of boronic ester monomer), 98.3 mg (0.361 mmol) of cumyl dithiobenzoate,
22.1 g (86.9 mmol) of lauryl methacrylate (LMA) and 26.5 mL of anisole are introduced into a
100-mL Schlenk tube. The reaction medium is placed under stirring and 11.9 mg (0.0722 mmol) of
30 azobisisobutyronitrile (AIBN) in solution in 120 μ1_, of anisole is introduced into the Schlenk tube.
The reaction medium is then degassed for 30 minutes by bubbling argon through it before being
brought to 65°C for a period of 16 hours. The Schlenk tube is placed in an ice bath in order to stop
the polymerization, then the polymer is isolated by precipitation from anhydrous acetone, followed
by filtration and drying under vacuum at 30°C overnight.
35 A copolymer is thus obtained, having the following structure:
45
5
with m =0.96 and n=0.04.
The boronic ester copolymer obtained has a number-average molar weight (M.) equal to 37,200
10 g/mol, a polydispersity index (PDI) equal to 1.24 and a number-average degree of polymerization
(DP„) equal to 166. These values are obtained respectively by steric exclusion chromatography
using tetrahydrofuran as eluent and a polystyrene calibration and by monitoring the conversion to
monomers during the copolymerization. NMR analysis of the proton of the final copolymer gives a
composition of 4 mol.% boronic ester monomer and 96% lauryl methacrylate.
15
3. Rheological studies of the formulations of polymers in solution in a base oil of Group
III according to the API classification.
20 o 3.1 Equipment and protocols for measuring viscosity
The rheological studies were carried out using a stress-controlled Couette MCR 501
rheometer from the company Anton Paar. The measurements were carried out on formulations of
polymers in solution in a Group III base oil using a cylindrical geometry of reference DG 26.7. The
viscosity was measured as a function of the shear rate in the case of a temperature range varying
25 from 10°C to 110°C. For each temperature, the viscosity of the system was measured as a function
of a shear rate of 0.01 to 1000 s-t. The measurements of viscosity as a function of the shear rate at
T = 10°C, 20°C, 30°C, 50°C, 70°C, 90°C and 110°C were carried out (ranging from 10°C to
110°C) followed by new measurements at 10°C and/or 20°C in order to assess the reversibility of
the systems. An average viscosity was then calculated for each temperature using the measurement
30 points situated on the same plate.
The relative viscosity
'isolation
(r1 relative —
11 base oil
was also selected in order to represent the change in the viscosity of the system as a function of
temperature, as this variable directly reflects the compensation for the loss of natural viscosity of
35 the base oil of Group III of the polymer systems studied.
46
o 3.2: Compositions based on polydiol statistical copolymers Al and boronic diester compounds
A2.
n Compositions tested
5 Copolymers Al:
Four poly(alkyl methacrylate-co-alkyldiol methacrylate) statistical copolymers of the
invention are tested. The copolymers are as follows:
3 Copolymer A1-1: This copolymer comprises 20 mol.% monomers having diol functions.
The average side chain length is 13.8 carbon atoms. Its number-average molar weight is
10 49,600 g/mol. Its polydispersity index is 1.51. Its number-average degree of
polymerization (DP„) is 167. The number-average molar weight and the polydispersity
index are measured by steric exclusion chromatography measurement using a polystyrene
calibration.
3 Copolymer A1-2: This copolymer comprises 20 mol.% monomers having diol functions.
15 The average side chain length is 10.8 carbon atoms. Its number-average molar weight is
59,700 g/mol. Its polydispersity index is 1.6. Its number-average degree of
polymerization (DPn) is 196. The number-average molar weight and the polydispersity
index are measured by steric exclusion chromatography measurement using a polystyrene
calibration.
20 3 Copolymer A1-3: This copolymer comprises 10 mol.% monomers having diol functions.
The average side chain length is 13.8 carbon atoms. Its number-average molar weight is
47,800 g/mol. Its polydispersity index is 1.3. Its number-average degree of
polymerization (DP„) is 198. The number-average molar weight and the polydispersity
index are measured by steric exclusion chromatography measurement using a polystyrene
25 calibration.
3 Copolymer A1-4: This copolymer comprises 10 mol.% monomers having diol functions.
The average side chain length is 13.8 carbon atoms. Its number-average molar weight is
97,100 g/mol. Its polydispersity index is 3.11. Its number-average degree of
polymerization (DP„) is 228. The number-average molar weight and the polydispersity
30 index are measured by steric exclusion chromatography measurement using a polystyrene
calibration.
The copolymers A1-1, A1-2, A1-3 and A1-4 are obtained according to one of the protocols
described in paragraph 1.
35 Compound A2:
Compound A2-1 is the boronic diester obtained according to the protocol described in
paragraph 2.1.
47
Lubricating base oil
The lubricating base oil used in the compositions to be tested is an oil of Group III of the
API classification, marketed by SK under the name Yubase 4. It has the following characteristics:
- its kinematic viscosity at 40°C measured according to the standard ASTM D445 is 19.57
5 cSt;
- its kinematic viscosity measured at 100°C according to the standard ASTM D445 is 4.23
cSt;
its viscosity index measured according to the standard ASTM D2270 is 122;
its Noack volatility in percentage by weight, measured according to the standard DIN 51581
10 is 14.5;
Its flash point in degrees Celsius measured according to the standard ASTM D92 is 230°C;
Its pour point in degrees Celsius measured according to the standard ASTM D97 is -15°C.
Composition A (not according to the invention) is used as reference.
15 It contains a solution with 4.2% by weight of a polymethacrylate polymer in a lubricating
base oil of Group III of the API classification. The polymer has a number-average molar weight
(Ma) equal to 106,000 g/mol, a polydispersity index (PDI) equal to 3.06, a number-average degree
of polymerization of 466 and the average pendant chain length is 14 carbon atoms.
This polymethacrylate is used as viscosity index improver additive.
20 4.95 g of a formulation having a concentration by weight of 42% of this polymethacrylate
in a Group III base oil and 44.6 g of Group III base oil are introduced into a flask. The solution thus
obtained is maintained under stirring at 90°C until the polymethacrylate is completely dissolved.
A solution with 4.2% by weight this polymethacrylate is obtained.
25
Composition B-1 (not according to the invention) is obtained as follows:
4.14 g of polydiol copolymer A1-1 and 37.2 g of Group III base oil are introduced into a
flask. The solution thus obtained is maintained under stirring at 90°C until the polydiol is
completely dissolved.
30 A solution with 10% by weight polydiol copolymer A1-1 is obtained.
Composition C-1 (according to the invention) is obtained as follows:
8 g of the solution with 10% by weight polydiol copolymer A1-1 in the Group III base oil
prepared previously is introduced into a flask. 55.8 mg of boronic diester A2-1 is added to this
35 solution. The solution thus obtained is maintained under stirring at 90°C until the boronic diester is
completely dissolved.
A solution with 10% by weight polydiol copolymer A1-1 and 20 mol.% boronic diester
A2-1 with respect to the diol functions of the polydiol copolymer A1-1 is obtained.
48
Composition D-1 (according to the invention) is obtained as follows:
8 g of the solution with 10% by weight polydiol copolymer Al-1 in the Group III base oil
prepared previously is introduced into a flask. 223 mg of boronic diester A2-1 is added to this
5 solution. The solution thus obtained is maintained under stirring at 90°C until the boronic diester is
completely dissolved.
A solution with 10% by weight polydiol copolymer A1-1 and 80 mol.% boronic diester
A2-1 with respect to the diol functions of the polydiol copolymer Al-1 is obtained.
10 Composition B-2 (not according to the invention) is obtained as follows:
6.52 g of polydiol copolymer A1-2 and 58.7 g of Group III base oil are introduced into a
flask. The solution thus obtained is maintained under stirring at 90°C until the polydiol is
completely dissolved.
A solution with 10% by weight polydiol copolymer A1-2 is obtained.
15
Composition C-2 (according to the invention) is obtained as follows:
8 g of the solution with 10% by weight polydiol copolymer A1-2 in the Group III base oil
prepared previously is introduced into a flask. 65.4 mg of boronic diester A2-1 is added to this
solution. The solution thus obtained is maintained under stirring at 90°C until the boronic diester is
20 completely dissolved.
A solution with 10% by weight polydiol copolymer Al-2 and 20 mol.% boronic diester
A2-1 with respect to the'diol functions of the polydiol copolymer A1-2 is obtained.
Composition D-2 (according to the invention) is obtained as follows:
25
8 g of the solution with 10% by weight polydiol copolymer A1-2 in the Group III base oil
prepared previously is introduced into a flask. 262 mg of boronic diester A2-1 is added to this
solution. The solution thus obtained is maintained under stirring at 90°C until the boronic diester is
completely dissolved.
A solution with 10% by weight polydiol copolymer Al-2 and 80 mol.% boronic diester
30 A2-1 with respect to the diol functions of the polydiol copolymer A1-2 is obtained.
Composition B-3 (not according to the invention) is obtained as follows:
7.24 g of polydiol copolymer Al-3 and 65.2 g of Group III base oil are introduced into a
flask. The solution thus obtained is maintained under stirring at 90°C until the polydiol is
35 completely dissolved.
A solution with 10% by weight polydiol copolymer Al-3 is obtained.
Composition C-3 (according to the invention) is obtained as follows:
49
8 g of the solution with 10% by weight polydiol copolymer Al-3 in the Group III base oil
prepared previously is introduced into a flask. 28.2 mg of boronic diester A2-1 is added to this
solution. The solution thus obtained is maintained under stirring at 90°C until the boronic diester is
completely dissolved.
5 A solution with 10% by weight polydiol copolymer Al-3 and 20 mol.% boronic diester
A2-1 with respect to the diol functions of the polydiol copolymer A1-3 is obtained.
Composition B-4 (not according to the invention) is obtained as follows:
4.99 g of polydiol copolymer Al-4 and 44.4 g of Group III base oil are introduced into a
10 flask. The solution thus obtained is maintained under stirring at 90°C until the polydiol is
completely dissolved.
A solution with 10% by weight polydiol copolymer A1-4 is obtained.
Composition C-4 (according to the invention) is obtained as follows:
15 6.01 g of the solution with 10% by weight polydiol copolymer A1-4 in the Group III base
oil prepared previously is introduced into a flask. 18.6 mg of boronic diester A2-1 is added to this
solution. The solution thus obtained is maintained under stirring at 90°C until the boronic diester is
completely dissolved.
A solution with 10% by weight polydiol copolymer A1-4 and 20 mol.% boronic diester
20 A2-1 with respect to the diol functions of the polydiol copolymer A1-4 is obtained.
Composition D-4 (according to the invention) is obtained as follows:
6.03 g of the solution with 10% by weight polydiol copolymer A1-4 in the Group III base
oil prepared previously is introduced into a flask. 74.7 mg of boronic diester A2-1 is added to this
25 solution. The solution thus obtained is maintained under stirring at 90°C until the boronic diester is
completely dissolved.
A solution with 10% by weight polydiol copolymer A1-4 and 80 mol.% boronic diester
A2-1 with respect to the diol functions of the polydiol copolymer A1-4 is obtained.
30 n Rheology results obtained
The rheological behaviour of composition C1-1 was studied in the case of a temperature
range from 10°C to 110°C. The results are presented in Figure 5. The dynamic viscosity of
composition C1-1 varies at low shear rates and for temperatures below 50°C. Composition C1-1
35 deforms under shear stress at temperatures below 50°C.
In the case of temperatures above 50°C, the dynamic viscosity of composition C1-1 varies
very slightly or does not vary at low shear rates. Composition CI-1 no longer deforms under shear
stress at these temperatures.
50
The relative viscosity of compositions A, B-1, C-1, D-1, B-2, C-2, D-2, B-3, C-3, D-3, B-4,
C-4, D-4 was studied. The change in the relative viscosity of these compositions is illustrated in
Figures 6A-6D. By comparing the results obtained, it is observed that certain parameters influence
5 the relative viscosity of the compositions.
v The influence of Lc (average pendant side chain length)
The polydiol copolymers A1-1 and A1-2 have the same percentage of diol monomer MI
per chain, comparable molar weights, but a different average alkyl chain length of the monomers
10 (Lc = 13.8 and Lc = 10.8 respectively).
The change in the relative viscosity as a function of the temperature for the solutions
formulated from these polymers (Figure 6A and 6B) indicates that the average alkyl chain length of
the monomers constituting the polydiol copolymer plays a role in the rheological properties of the
formulations.
15
v The influence of the molar percentage of diol monomer (1)/0 diol)
The polydiol copolymers A1-1 and A1-3 have the same average alkyl chain length (Lc),
comparable molar weights but a different percentage of diol monomer MI per backbone chain
(20% and 10% respectively).
20 The change in the relative viscosity as a function of the temperature for the solutions
formulated from these polymers (Figure 6A and 6C) indicates that the percentage of diol monomer
per backbone chain plays a role in the rheological properties of the formulations.
v The influence of the molar weights and degrees of polymerization (DP,)
25 The polydiols A1-3 and Al-4 have the same percentage of diol monomer M1 per chain, the
same average alkyl chain length (Lc) but molar weights (47,800 g/mol and 97,100 "g/mol
respectively) and substantially different number-average degrees of polymerization (DP„ of 198
and 228 respectively).
The change in the relative viscosity as a function of the temperature for the solutions
30 formulated from these polymers (Figure 6.0 and 6.D) indicates that the molar weight of the
polydiol copolymers (Mn) plays a role in the rheological properties of the formulations.
o 3.2: Compositions based on polvdiol statistical copolymers Al and boronic ester polymer
compounds A2.
35
n Compositions tested
Copolymers Al:
A poly(alkyl methacrylate-co-alkyldiol methacrylate) statistical copolymer of the invention
51
is tested. The copolymer is as follows:
3 Copolymer A1-1: This copolymer comprises 20 mol.% monomers having diol functions.
The average side chain length is 13.8 carbon atoms. Its number-average molar weight is
49,600 g/mol. Its polydispersity index is 1.51. Its number-average degree of
5
polymerization (DP„) is 167. The number-average molar weight and the polydispersity
index are measured by steric exclusion chromatography measurement using a polystyrene
calibration.
Copolymer A1-1 is obtained according to one of the protocols described in paragraph 1.
10 Compound A2:
Compound A2-2 is the boronic ester polymer obtained according to the protocol
described in paragraph 2.2. This copolymer comprises 4 mol.% monomers having boronic ester
functions. The average side chain length is greater than 12 carbon atoms. Its number-average molar
weight is 37,200 g/mol. Its polydispersity index is 1.24. Its number-average degree of
15 polymerization (DP,i) is 166. The number-average molar weight and the polydispersity index are
measured by steric exclusion chromatography measurement using a polystyrene calibration.
Lubricating base oil
The lubricating base oil used in the compositions to be tested is the Group III oil described
20 previously in paragraph 3.1.
The composition A (not according to the invention) used as reference is the same as the
composition A used in paragraph 3.1.
25 Composition B (not according to the invention) is obtained as follows:
Composition B is the same composition B-1 used in paragraph 3.1.
Composition C (according to the invention) is obtained as follows:
4 g of the solution with 10% by weight polydiol copolymer A1-1 in the Group III base oil
30 prepared previously is introduced into a flask. 76.8 mg of boronic ester polymer A2-2 and 4 g of
the Group III base oil are added to this solution. The solution thus obtained is maintained under
stirring at 90°C until the boronic ester polymer is completely dissolved.
A solution with 5% by weight polydiol copolymer A1-1 and 1% by weight boronic ester
polymer A2-2 with respect to the total weight of the composition is obtained.
35
Composition D (according to the invention) is obtained as follows:
6 g of the preceding composition C (i.e. a composition at 5% by weight polydiol copolymer
Al-1 and 1% by weight boronic ester polymer A2-2 with respect to the total weight of the
52
composition) is introduced into a flask. 61.9 mg of boronic ester polymer A2-2 is added to this
solution. The solution thus obtained is maintained under stirring at 90°C until the boronic ester
polymer is completely dissolved.
A solution with 5% by weight polydiol copolymer A1-1 and 2% by weight boronic ester
5 polymer A2-2 with respect to the total weight of the composition is obtained.
Composition E (according to the invention) is obtained as follows:
3 g of the solution with 10% by weight polydiol copolymer A1-1 in the Group III base oil
prepared previously is introduced into a flask. 176 mg of boronic ester polymer A2-2 and 3 g of the
10 Group III base oil are added to this solution. The solution thus obtained is maintained under stirring
at 90°C until the boronic ester polymer is completely dissolved.
A solution with 5% by weight polydiol copolymer A1-1 and 3% by weight boronic ester
polymer A2-2 with respect to the total weight of the composition is obtained.
15 n Rheology results obtained
The rheological behaviour of composition E was studied in the case of a temperature range
from 10°C to 110°C. The results are presented in Figure 7. The dynamic viscosity of composition E
varies at low shear rates and for temperatures below 50°C. Composition E deforms under shear
stress at temperatures below 50°C.
20 In the case of temperatures above 50°C, the dynamic viscosity of composition E varies
very slightly or does not vary at low shear rates. Composition E no longer deforms under shear
stress at these temperatures.
The relative viscosity of compositions A, B, C, D and E was studied. The change in the
25 relative viscosity of these compositions is illustrated in Figure 8. This figure indicates that the
polydiol/poly(boronic ester) systems make it possible to very significantly compensate for the drop
in natural viscosity of the base oil as a function of the temperature. Furthermore, the effect obtained
can be regulated by adjusting the concentrations by weight of the different polymers in solution in
the base oil III.
30
4 Synthesis of Poly(Styrene-Alkyldiol Methacrylate) statistical copolymers Al
The synthesis of the styrene-methacrylate copolymers bearing diol functions according to
the invention is carried out in two steps:
35 — Copolymerization of the styrene monomer with a methacrylate monomer bearing a diol
function protected in the ketal form;
— Deprotection of the diol functions of the copolymer
53
The following procedures describe the synthesis of a poly(styrene-co-alkyldiol methacrylate)
copolymer containing approximately 10 mol.% diol monomer units.
More precisely, the synthesis of the copolymer is carried out according to the following
5 protocol:
3.03 g (12.50 mmol) of hexyldiol methacrylate monomer bearing a diol function protected in
ketal form obtained according to the protocol described in paragraph 1.1.1, 11.6 g (111.7 mmol) of
styrene and 50.8 mg of 2-phenyl-2-propyl benzodithioate (0.187 mmol) in solution in 0.89 g of
anisole are introduced into a 100-mL Schlenk tube. The reaction medium is then placed under
10 stirring then degassed for 30 minutes by bubbling nitrogen through it before being brought to
120°C for a period of 30 hours. The Schlenk tube is then placed in a cold water bath in order to
stop the polymerization and 20 mL of tetrahydrofuran is then added to the reaction medium. The
polymer is isolated by precipitation from methanol at ambient temperature, followed by filtration
and drying under vacuum at 30°C for 17 hours.
15 A copolymer is thus obtained, having a number-average molar weight (Mn) of 39,600 g/mol
equivalent of polystyrene, a polydispersity index (PDI) of 1.47 and a number-average degree of
polymerization of 541 (89 mol.% styrene). These values are obtained respectively by steric
exclusion chromatography using tetrahydrofuran as eluent and polystyrene calibration, and by
NMR monitoring of the conversion to monomers during the polymerization.
20 Deprotection of the copolymer is carried out according to the following protocol:
9.72 g of copolymer obtained in the preceding step and containing approximately 10%
protected functions diol is introduced into a 500-mL flask containing 280 mL of dioxane in order to
solubilize the polymer. 36 mL of an aqueous solution of hydrochloric acid (1 mol/L) is added. The
medium then becomes completely opaque. After 24 hours under stirring at 25°C, the medium has
25 again become transparent. 1.5 mL of hydrochloric acid (36% by weight) is then added to the
medium before the latter is left under stirring at 25°C for 24 hours. Once the deprotection is
completed, the medium again becomes perfectly transparent. The polymer is isolated by two
successive precipitations from methanol at ambient temperature, followed by filtration and drying
under vacuum at 30°C for 17 hours.
30 A poly(styrene-co-alkyldiol methacrylate) copolymer having a number-average molar
weight (Mn) of 43,800 g/mol equivalent of polystyrene, a polydispersity index (PDI) of 1.34 is
obtained.
5 Synthesis of Poly(Styrene-phenylboronic ester Styrene) statistical copolymers A2
35
The synthesis of another compound A2, styrene-phenylboronic ester styrene copolymer, is
carried out according to the following protocol:
54
1.00 g of a mixture of boronic ester monomer and 1,2-propanediol previously prepared in
accordance with paragraph 2.2.1 (containing 3.06 mmol of boronic ester monomer), 8.59 g (82.5
mmol) of styrene and 33.5 mg of 2-phenyl-2-propyl benzodithioate (0.123 mmol) in solution in
0.59 g of anisole are introduced into a 30-mL Schlenk tube. The reaction medium is then placed
5 under stirring then degassed for 30 minutes by bubbling nitrogen through it before being brought to
120°C for a period of 24 hours. The Schlenk tube is placed in a cold water bath in order to stop the
polymerization and 15 mL of tetrahydrofuran is then added to the reaction medium. The polymer is
isolated by precipitation in hexane at ambient temperature, followed by filtration and drying under
vacuum at 30°C for 17 hours.
10
A copolymer is thus obtained, having a number-average molar weight (Mn) of 35,200 g/mol, a
polydispersity index (PDI) of 1.31 and a number-average degree of polymerization of 528 (96
mol.% styrene). These values are obtained respectively by steric exclusion chromatography using
tetrahydrofuran as eluent and a polystyrene calibration, and by NMR monitoring of the conversion
to monomers during the polymerization.
15
6. Rheological studies of the formulations of polymers in solution in tetralin.
6.1 Equipment and protocols for measuring viscosity
The rheological studies were carried out using a stress-controlled Couette MCR 302
20 rheometer from the company Anton Paar.
The rheology measurements were carried out using a cylindrical geometry of reference DG
26.7. The viscosity was measured as a function of the shear rate in the case of a temperature range
varying from 50°C to 100°C. For each temperature, the viscosity of the system was measured as a
function of the shear rate from 0.1 to 200 s-1 for the study of tetralin alone and from 1 to 500 s"` for
25 compositions A and B. The measurements of viscosity as a function of the shear rate at T = 50°C,
60°C, 70°C, 80°C, 90°C and 100°C were carried out (ranging from 50°C to 100°C). An average
viscosity was then calculated for each temperature using the measurement points situated on the
same plate.
The relative viscosity
17 solution
(n relative = ribose oil
30
was selected to represent the change in the viscosity of the system as a function of
temperature, as this variable directly reflects the compensation of the polymer systems studied for
the loss of natural viscosity of the tetralin.
55
6.2. Compositions in tetralin
Tetralin
1,2,3,4-Tetrahydronaphthalene, also called tetralin, used in the compositions to be tested is a
low-volatility apolar hydrocarbon solvent. It has the following characteristics according to the
5 information given by the supplier:
Its density is 0.966;
Its melting point is -36°C;
Its boiling point is located between 206 and 207°C;
Its flash point is 77°C.
10
Copolymer A1-5
This copolymer comprises 10 mol.% monomers having diol functions and 90 mol.% styrene
monomers. Its number-average molar weight is 43,800 g/mol. Its polydispersity index is 1.34. The
number-average molar weight and the polydispersity index are measured by steric exclusion
15 chromatography using a polystyrene calibration.
This copolymer is obtained according to the process described in paragraph 4.
Copolymer A2-3
This copolymer comprises 4 mol.% monomers having boronic ester functions and 96 mol.%
20 styrene monomers. Its number-average molar weight is 35,200 g/mol. Its polydispersity index is
1.31. The number-average molar weight and the polydispersity index are measured by steric
exclusion chromatography using a polystyrene calibration.
This copolymer is obtained according to the process described in paragraph 5.
25 Stock solution B-5
1.00 g of polydiol copolymer A1-5 and 19.00 g of tetralin are introduced into a flask. The
solution thus obtained is maintained under stirring at ambient temperature for 4 hours until the
polydiol A1-5 is completely dissolved.
A solution containing 5% polydiol copolymer A1-5 by weight is obtained.
30
Stock solution C-5
1.00 g of poly(boronic ester) copolymer A2-3 and 19.00 g of tetralin are introduced into a
flask. The solution thus obtained is maintained under stirring at ambient temperature for 4 hours
until the poly(boronic ester) A2-3 is completely dissolved.
35 A solution containing 5% poly(boronic ester) copolymer A2-3 by weight is obtained.
Composition F
0.1 mL of stock solution C-5 containing 5% poly(boronic ester) copolymer A2-3 by weight
56
in the tetralin prepared previously is introduced into a flask to which 0.9 mL of tetralin is added.
The solution is left under stirring for 2 minutes in an oil bath heated at 90°C. 4 mL of the stock
solution B-5 containing 5% polydiol copolymer A1-5 by weight is then added to this solution
leaving the flask in the bath and under stirring. The solution thus obtained is maintained under
5 stirring at 90°C for an hour.
A solution containing 4% polydiol copolymer A1-5 by weight and 0.1% poly(boronic ester)
copolymer A2-3 by weight is obtained.
Composition G
10 0.3 mL of stock solution C-5 containing 5% copolymer poly(boronic ester) A2-3 by weight
in the tetralin prepared previously is introduced into a flask to which 1.7 mL of tetralin is added.
The solution is left under stirring for 2 minutes in an oil bath heated at 50°C. 3 mL of the stock
solution B-5 containing 5% polydiol copolymer A1-5 by weight is then added to this solution
leaving the flask in the bath and under stirring. The solution thus obtained is maintained under
15 stirring at 50°C for an hour.
A solution containing 3% polydiol copolymer A1-5 by weight and 0.3% poly(boronic ester)
copolymer A2-3 by weight is obtained.
20 6.3. Rheology results
The rheological behaviour of compositions F and G was studied in the case of a temperature
range from 50 to 100°C. The results are shown in Figure 10. It is observed that the poly(styrenealkyldiol
methacrylate) copolymer A1-5 and the poly(styrene—phenylboronic ester styrene)
25 copolymer A2-3 make it possible to compensate for the reduction in viscosity of the tetralin when
the temperature increases.
57
CLAIMS
1. Composition resulting from the mixture of at least:
o a statistical copolymer Al resulting from the copolymerization:
5
• of at least one first monomer MI of general formula (I):
Ri
10
H2C
Xi 0
OX2
15 (I)
in which:
- R1 is selected from the group formed by —H, —CH3, and —CH2-CH3;
- x is an integer ranging from 2 to 18;
- y is an integer equal to 0 or 1;
20 - X1 and X2, identical or different, are selected from the group formed by
hydrogen, tetrahydropyranyl, methyloxymethyl, ter-butyl, benzyl,
trimethylsilyl and t-butyl dimethylsilyl;
or
— X1 and X2 form with the oxygen atoms a bridge of the following formula
25
in which:
- the stars (*) symbolize the bonds to the oxygen atoms,
30
- R'2 and R"2, identical or different, are selected from the group
formed by hydrogen and a C1-C11 alkyl, preferably methyl;
or
— X1 and X2 form with the oxygen atoms a boronic ester of the following
formula
B/RH1 2
35
\*
in which:
58
the stars (*) symbolize the bonds to the oxygen atoms,
- R"'2 is selected from the group formed by a C6-C18 aryl, a C7-
C18 aralkyl and C2-C18 alkyl, preferably a C6-C18 aryl;
n with at least one second monomer M2 of general formula (II):
5
R2
H2C
R3
in which:
10 - R2 is selected from the group formed by —H, —CH3 and —CH2—CH3,
- R3 is selected from the group formed by a C6-C18 aryl, a C6-C18 aryl
substituted by an R'3, —C(0)-0—R'3;
—0—R'3, —S—R'3 and —C(0)—N(H)—R'3 group with R'3 a C1-C30 alkyl
group; and
15 o a compound A2 comprising at least two boronic ester functions.
2. Composition according to claim 1, in which the statistical copolymer Al results from the
copolymerization of at least one monomer M1 with at least two monomers M2 having different R3
groups.
20
3. Composition according to claim 2, in which one of the monomers M2 has the general
formula (II-A):
25
O
in which:
30 - R2 is selected from the group formed by —H, —CH3 and —CH2—CH3,
- R"3 is a C1-C14 alkyl group,
and the other monomer M2 has the general formula (II-B):
R"3
(II-A)
35
O
(II-B)
R6
0
0 B-0
\ /
B—L
0
R7
59
in which:
- R2 is selected from the group formed by —H, —CH3 and —CH2—CH3,
- R"'3 is a C15-C30 alkyl group.
5 4. Composition according to one of claims 1 to 3, in which the side chains of the statistical
copolymer Al have an average length ranging from 8 to 20 carbon atoms, preferably from 9 to 15
carbon atoms.
5. Composition according to one of claims 1 to 4, in which the statistical copolymer A 1 has a
10 molar percentage of monomer MI of formula (I) in said copolymer ranging from 1 to 30%,
preferably from 5 to 25%, more preferably ranging from 9 to 21%.
6. Composition according to one of claims 1 to 5, in which the statistical copolymer A 1 has a
number-average degree of polymerization ranging from 100 to 2000, preferably from 150 to 1000.
15
7. Composition according to one of claims 1 to 6, in which the statistical copolymer Al has a
polydispersity index (PDI) ranging from 1.05 to 3.75; preferably ranging from 1.10 to 3.45.
20 8. Composition according to claim 1, in which the compound A2 is a compound of formula
(III):
25
III
in which:
30 - wi and w2, identical or different are integers selected between 0 and 1;
- R4, R5, R6 and R7, identical or different are selected from the group formed by
hydrogen and a hydrocarbon-containing group having from 1 to 24 carbon atoms,
preferably between 4 and 18 carbon atoms, preferably between 6 and 14 carbon
atoms;
35 - L is a divalent bond group and selected from the group formed by a C6-C18 aryl, a
C6-C18 aralkyl and a C2-C24 hydrocarbon-containing chain.
9. Composition according to claim 1, in which the compound A2 is a statistical copolymer
60
resulting from the copolymerization
• of at least one monomer M3 of formula (IV):
5 0
B—M
0
/ X—(R8).
R11
H2C (IV)
10 in which:
— t is an integer equal to 0 or 1;
— u is an integer equal to 0 or 1;
— M and R8 are divalent bond groups, identical or different, selected from the
group formed by a C6-C18 aryl, a C2-C24 aralkyl and a C2-C24 alkyl, preferably a
15 C6-C 18 aryl,
— X is a function selected from the group formed by —0—C(0)—, —C(0)-0—,
—C(0)—N(H)—, —N(H)--C(0) -, —S—, —N(R'4)— and —0— with R'4 a
hydrocarbon-containing chain comprising from 1 to 15 carbon atoms;
— R9 is selected from the group formed by —H, —CH3 and—CH2—CH3;
20
— R10 and R11 identical or different are selected from the group formed by
hydrogen and a hydrocarbon-containing group having from 1 to 24 carbon
atoms, preferably between 4 and 18 carbon atoms, preferably between 6 and 14
carbon atoms;
with at least one second monomer M4 of general formula (V):
25
R12
H2C
R13
(V)
in which:
30 - R12 is selected from the group formed by —H, —CH3 and —CH2--CH3,
- R13 is selected from the group formed by a C6-C18 aryl, a C6-C18 aryl
substituted by an R' 13, -C(0)-0-R'13i —0—R913, —S—R913 and —C(0)—N(H)—
R' 13 group with R' 13 a C1-C25 alkyl group.
35 10. Composition according to claim 9, in which the chain formed by the sequence of the R10, M,
X and (R8)„ groups with u equal to 0 or 1 of the monomer of general formula (IV) has a total
number of carbon atoms ranging from 8 to 38, preferably from 10 to 26.
61
11. Composition according to one of claims 9 to 10, in which the side chains of the copolymer
A2 have an average length greater than or equal to 8 carbon atoms, preferably ranging from 11 to
16 carbon atoms.
5 12. Composition according to one of claims 9 to 11, in which the copolymer A2 has a molar
percentage of monomer of formula (IV) in said copolymer ranging from 0.25 to 20%, preferably
from 1 to 10%.
13. Composition according to one of claims 9 to 12, in which the copolymer A2 has a number-
10 average degree of polymerization ranging from 50 to 1500, preferably from 80 to 800.
14. Composition according to one of claims 9 to 13, in which the copolymer A2 has a
polydispersity index (PDI) ranging from 1.04 to 3.54; preferably ranging from 1.10 to 3.10.
15 15. Composition according to one of claims 1 to 14, in which the copolymer Al content ranges
from 0.1% to 50% by weight with respect to the total weight of the composition.
16. Composition according to one of claims 1 to 15, in which the compound A2 content ranges
from 0.1% to 50% by weight with respect to the total weight of the composition.
20
17. Composition according to one of claims 1 to 16, in which the ratio by weight between the
copolymer A 1 and the compound A2 (ratio Al/A2) ranges from 0.005 to 200, preferably from 0.05
to 20, even more preferably from 0.1 to 10.
25 18. Composition according to any one of claims 1 to 17 further comprising at least one additive
selected from the group formed by the polymers, pigments, dyes, fillers, plasticizers, fibres,
antioxidants, additives for lubricants, compatibilizing agents, anti-foaming agents, dispersant
additives, adhesion promoters and stabilizing agents.