POLYMERIC MATERIALS
This invention relates to a polymeric material and particularly, although not exclusively,
relates to a polyaryletherketone, especially polyetheretherketone.
Polyaryletheretherketones, in general, have exceptional mechanical and chemical, for
example solvent resistance, properties. For satisfactory mechanical properties (e.g. tensile
strength, flexural strength, flexural modulus and/or elongation at break), the molecular weight
(e.g. quantified in terms of reduced viscosity (RV), inherent viscosity (IV) or melt viscosity
(MV)) needs to be above a minimum level. For satisfactory chemical properties, the
crystallinity of the polymeric material needs to be high.
EP1 879 describes the preparation and use of semi-crystalline polyaryletherketones,
especially polyetheretherketone (PEEK) and suggests that, to be mechanically useful,
polyaryletherketones must have an inherent viscosity (IV) of at least 0.7 dig 1 (which
corresponds to a reduced viscosity (RV) of at least 0.8 dig 1) .
It has been recognised that it can be difficult to use polyaryletherketones having an IV of
at least 0.7 dig 1 in making complex parts by injection moulding or making highly filled
composite materials, since, at the specified IV, the viscosity of the polymeric material may be
too high for satisfactory flow into narrow openings in moulds and/or may be too high to fully
wet out fillers, for example fibres, in composite materials.
US4541 884 recognises the problem of impregnating and/or wetting fibrous masses in
the production of composite materials and solves the problem by use of a melt comprising a
mixture of thermoplastic polymer and a relatively high level of plasticizer for the polymer which
is thermally stable but can be volatilised from the melt. Use of the plasticizer plasticizes the
polymer in the melt to provide a melt of reduced viscosity compared with the melt viscosity of
the polymer alone. Subsequently, it is volatilised.
WO2005/030836 solves the problem, inter alia, of injection moulding components
having relatively thin walls by using a polyaryletherketone having a relatively low melt viscosity
(MV) in the range 0.05 to 0 .12 KNsm 2 which was found, contrary to the teaching in EP 1879,
to have excellent mechanical properties. WO2006/1 06352 discloses using the same low MV
polyaryletherketone to produce highly filled polymeric materials.
US521 3889 solves the problem of wetting of fibrous masses in producing a composite
material by using a thermoplastic polymer having a very low melt viscosity to enable wetting of
the fibres. The disclosure envisages processing steps to increase the molecular weight of the
polymer, after preparation of the composite material, to improve its mechanical properties.
US4638037 describes one method of increasing molecular weight of
polyaryletherketones which, in preferred embodiments, comprises introducing an alkaline salt
of a Group I or Group II metal at a concentration of at least 0.005 wt%. The salt has
nucleophilic activity. When the mixture of polymer and salt is heated to a temperature above
the melting point of the polymer, the molecular weight (e.g. MV) of the polymer increases.
Disadvantageously, however, it is difficult to control the process and use of the salt
contaminates the polymer, which may necessitate an additional purification step to reduce salt
levels in the polymer.
It should be appreciated that, whilst it may be possible to increase molecular weight of
polyaryletherketones by using various methods, it is important to retain a sufficient level of
crystallinity (in addition to improved mechanical properties) if the polyaryletherketone is to be
usable in situations wherein both mechanical and chemical properties are important. Thus,
whilst molecular weight of polymeric materials may be increased by cross-linking, that often
leads to a significant, detrimental reduction in crystallinity.
Thus, any process for improving mechanical properties of polyaryletherketones should,
ideally, still retain substantial crystallinity in the polyaryletherketone. Furthermore, other
physical properties, for example glass transition temperature (Tg) and melting temperature
(Tm) should be satisfactory. Additionally, any process used should ideally: not produce any
undesirable by-products (e.g . salts or gases); be usable in existing chemical plants which
produce polyaryletherketones (e.g. not require significant additional equipment or process
steps); produce parts with improved properties without significant additional downstream
processing (e.g. curing or purification steps); and allow the polymeric material to be melt
processed in substantially the same manner as used for existing commercially available
polyaryletherketones.
It is one object of the invention to address at least some of the aforementioned
problems.
It is an object of preferred embodiments of the invention to provide a polymeric material
which can be used to produce parts (which may include thin walls and/or may be highly filled)
having excellent mechanical and chemical properties.
According to a first aspect of the invention, there is provided a polymeric material
comprising a repeat unit of formula
wherein t 1 and w 1 independently represent 0 or 1 and v 1 represents 0 , 1 or 2 ;
wherein said polymeric material also includes a phenylethynyl moiety and wherein,
preferably, said polymeric material has a Reduced Viscosity (RV) of at least 0.6 dL/g.
Unless otherwise stated herein, RV is suitably measured as described in Procedure 1
hereinafter.
The presence and/or level of phenylethynyl moieties in said polymeric material may be
confirmed by 13C NMR or MALDI-ToF mass spectrometry.
Said polymeric material may have an RV of at least 0.6 dL/g, preferably at least 0.8
d/Lg. The RV may be less than 2.0 dL/g. Thus, said polymeric material preferably has an RV
in the range 0.6 to 2.0 dL/g , more preferably, the RV is in the range 0.7 to 1.0 dL/g; especially
0.7 to 0.8 dL/g.
Said phenylethynyl moiety may include a linking moiety L by means of which it is
incorporated into the polymeric material and/or by means of which it is bonded to the repeat
unit of Formula I.
Said linking moiety may include an aromatic moiety which is suitably bonded directly to
the phenylethynyl moiety (at an end opposite to the end of the ethynyl moiety which is bonded
to the phenyl moiety of said phenylethynyl moiety). Said phenylethynyl moiety may be of
formula
Ph -CºC-P 2-L1
wherein Ph represents optionally-substituted phenyl, Ph2 represents optionallysubstituted
phenyl and L represents a linking moiety by means of which said phenylethynyl
moiety II is incorporated into the polymeric material and/or by means of which it is bonded to
the repeat unit of Formula I.
L may comprise an aromatic moiety, suitably an aromatic moiety which includes an
aromatic 6-carbon atom containing ring, for example an optionally substituted phenyl moiety.
Moiety -Ph 2-L1 preferably comprises a benzophenone moiety.
Moiety -Ph2-L1 may be selected from the following:
(a)
wherein "a" or "b" represent the carbon atom bonded to the repeat unit of formula I and
the atom bonded to the ethynyl carbon atom is selected from "c", "d" and "e".
In compound V, "b" preferably represents the carbon atom bonded to the repeat unit of
formula I and the atom bonded to the ethynyl carbon atom is selected from "d" or "e"; and
(b)
wherein "a" or "b" represent the carbon atom bonded to the repeat unit of formula I and
the atom bonded to the ethynyl carbon atom is atom "c".
Preferred moieties -Ph2-L1 are of formula V.
Moiety Ph may be selected from an unsubstituted phenyl moiety and a phenyl moiety
substituted with an optionally-substituted phenylcarbonyl moiety. Preferably, Ph1 is an
unsubstituted phenyl moiety.
Preferably, said polymeric material incorporates a phenylethynyl moiety which
comprises, preferably consists of, a moiety of formula
wherein the carbon atom bonded to another atom (e.g. the repeat unit of formula I) is
atom " .
The Tg and/or Tm of said polymeric material may be substantially the same (e.g . to
within ± 1°C) of the Tg and Tm of the same polymeric material but in the absence of said
phenylethynyl moiety.
Crystallinity of said polymeric material cannot be measured by techniques which involve
melting of the polymeric material because the phenylethynyl moiety will react leading to an
increase in molecular weight (e.g. RV). However, crystallinity may be measured by wide angle
X-ray diffraction (also referred to as Wide Angle X-ray Scattering or WAXS), for example as
described by Blundell and Osborn (Polymer 24, 953, 1993). The level of crystallinity in said
polymeric material, measured by WAXS as described , may be at least 5%, preferably at least
10%, more preferably at least 15%, especially at least 20%. The crystallinity may be less than
40% and less than 35%. Preferably, the crystallinity is in the range 15 to 35%.
Preferred polymeric materials have a said repeat unit wherein t 1= 1, v 1=0 and w 1=0;
t 1=0, v 1=0 and w 1=0; t 1=0, w 1= 1 , v 1=2; or t 1=0, v 1= 1 and w 1=0. More preferred have a
repeat unit wherein t 1= 1 , v 1=0 and w 1-0; or t 1=0, v 1=0 and w 1=0. The most preferred has a
repeat unit wherein t 1= 1 , v 1=0 and w 1=0.
Said polymeric material suitably includes at least 50 mol%, (e.g. 50-99.8 mol%),
preferably at least 60 mol% (e.g. 60-99.8 mol%), more preferably at least 68 mol% (e.g . 68 to
100 mol%), of repeat units of formula I, especially such units where t 1= 1, v 1=0 and w 1=0.
Other repeat units in said first polymer may be of formula I ; or may include -Ph-Ph- moieties
where Ph suitably represents an unsubstituted phenylene moiety (especially wherein both
-Ph- moieties are 4,4'-substituted). Other repeat units may include Ph moieties bonded to two
moieties selected from carbonyl moieties and ether moieties; and-Ph-Ph- moieties bonded to
two ether moieties.
Said polymeric material suitably includes at least 50 wt% (e.g. 50-99.8 wt%) of repeat
units of formula I.
Said polymeric material may be a copolymer which comprises a first moiety of formula I
and a second moiety which includes -Ph-Ph- moieties where Ph represents an unsubstituted
phenylene moiety (which suitably includes 4,4'-bonds to adjacent moieties).
In one embodiment, said polymeric material may be selected from: a polymer
comprising at least 98 mol% and/or comprising at least 98 wt% of a repeat unit of formula I ,
especially such units wherein t 1= 1, v 1=0 and w 1=0; and a copolymer which includes a repeat
unit of formula
-O-Ph-O-Ph-CO-Ph- VIII
and a repeat unit of formula
-O-Ph-Ph-O-Ph-CO-Ph- IX
wherein Ph represents a phenylene moiety.
Said polymeric material preferably includes at least 98 wt% (e.g. 98 to 99.9 wt%) of a
repeat unit of formula I or a copolymer which includes repeat units of formulae VIII and IX.
In said copolymer, said repeat units VII I and IX are preferably in the relative molar
proportions VII I :IX of from 65:35 to 95:5.
The phenylene moieties (Ph) in each repeat unit VII I and IX may independently have
1,4- para linkages to atoms to which they are bonded or 1,3- meta linkages. Where a
phenylene moiety includes 1,3- linkages, the moiety will be in the amorphous phase of the
polymer. Crystalline phases will include phenylene moieties with 1,4- linkages. It is preferred
for the polymeric material to be highly crystalline and , accordingly, the polymeric material
preferably includes high levels of phenylene moieties with 1,4- linkages.
In a preferred embodiment, at least 95% , preferably at least 99% , of the number of
phenylene moieties (Ph) in the repeat unit of formula VIII have 1,4-linkages to moieties to
which they are bonded . It is especially preferred that each phenylene moiety in the repeat unit
of formula VIII has 1,4- linkages to moieties to which it is bonded.
In a preferred embodiment, at least 95% , preferably at least 99% , of the number of
phenylene moieties (Ph) in the repeat unit of formula IX have 1,4-linkages to moieties to which
they are bonded . It is especially preferred that each phenylene moiety in the repeat unit of
formula IX has 1,4- linkages to moieties to which it is bonded.
Preferably, the phenylene moieties in repeat unit of formula VII I are unsubstituted.
Preferably, the phenylene moieties in repeat unit of formula IX are unsubstituted.
Said repeat unit of formula VII I suitably has the structure:
Said repeat unit of formula IX suitably has the structu
Said copolymer may include at least 68 mol%, preferably at least 7 1 mol% of repeat
units of formula X. Particular advantageous copolymers may include at least 72 mol%, or,
especially, at least 74 mol% of repeat units of formula X. Said copolymer may include less
than 90 mol% , suitably 82 mol% or less of repeat units of formula X. Said copolymer may
include 68 to 82 mol%, preferably 70 to 80 mol%, more preferably 72 to 77 mol% of units of
formula X.
Said copolymer may include at least 10 mol%, preferably at least 18 mol%, of repeat
units of formula XI. Said copolymer may include less than 32 mol% , preferably less than 29
mol% of repeat units of formula XI. Particularly advantageous copolymers may include 28
mol% or less; or 26 mol% or less of repeat units of formula XI. Said copolymer may include 18
to 32 mol%, preferably 20 to 30 mol%, more preferably 23 to 28 mol% of units of formula XI.
The sum of the mol% of units of formula X and XI in said copolymer is suitably at least
95 mol%, is preferably at least 98 mol% , is more preferably at least 99 mol% .
In an especially preferred embodiment, said polymeric material includes at least 90
mol%, preferably at least 95 mol% , more preferably at least 98 mol% , especially at least 99
mol% of repeat units of formula I, especially repeat units of formula I wherein t 1= 1 , v 1=0 and
w 1=0. Said polymeric material suitably include 95 to 99.9 mol% (preferably 98 to 99.9 mol%,
especially 99 to 99.8 mol%) of repeat units of formula I wherein t 1= 1, v 1=0 and w 1=0 and 0 .1
to 5 mol% (preferably 0.1 to 2 mol% , especially 0.2 to 1.0 mol% of phenylethynyl moieties. In
an especially preferred embodiment said polymeric material includes 99.2 to 99.8 mol% of
repeat units of formula I wherein t 1= 1, v 1=0 and w 1=0 and 0.2 to 0.8 mol% of said
phenylethynl moieties.
In said especially preferred embodiment, said polymeric material includes 98 to 99.9
wt% of repeat units of formula I .
In a preferred embodiment, said polymeric material includes moieties of structure
wherein n is an integer which is, on average, at least 18 , preferably at least 25, more
preferably at least 30. Integer n may be 200 or less.
Said polymeric material may be in the form of pellets or granules, wherein the pellets or
granules include at least 95 wt%, preferably at least 99 wt%, especially about 100 wt% of said
polymeric material. Pellets or granules may have a maximum dimension of less than 10mm,
preferably less than 7.5mm, more preferably less than 5.0mm.
Said polymeric material may be part of a composition which may include said polymeric
material and a filler means. Said filler means may include a fibrous filler or a non-fibrous filler.
Said filler means may include both a fibrous filler and a non-fibrous filler. A said fibrous filler
may be continuous or discontinuous.
A said fibrous filler may be selected from inorganic fibrous materials, non-melting and
high-melting organic fibrous materials, such as aramid fibres, and carbon fibre.
A said fibrous filler may be selected from glass fibre, carbon fibre, asbestos fibre, silica
fibre, alumina fibre, zirconia fibre, boron nitride fibre, silicon nitride fibre, boron fibre,
fluorocarbon resin fibre and potassium titanate fibre. Preferred fibrous fillers are glass fibre
and carbon fibre. A fibrous filler may comprise nanofibres.
A said non-fibrous filler may be selected from mica, silica, talc, alumina, kaolin, calcium
sulfate, calcium carbonate, titanium oxide, ferrite, clay, glass powder, zinc oxide, nickel
carbonate, iron oxide, quartz powder, magnesium carbonate, fluorocarbon resin, graphite,
carbon powder, nanotubes and barium sulfate. The non-fibrous fillers may be introduced in
the form of powder or flaky particles.
Said composition may define a composite material which could be prepared as
described in Impregnation Techniques for Thermoplastic Matrix Composites. A Miller and A G
Gibson, Polymer & Polymer Composites 4(7), 459 - 481 ( 1996), EP1 021 58 and EP1 021 59,
the contents of which are incorporated herein by reference. Preferably, in the method, said
polymeric material and said filler means are mixed at an elevated temperature, suitably at a
temperature at or above the melting temperature of said polymeric material, but below (e.g . at
least 30°C, 40°C or 50°C below) the temperature at which the ethynyl groups react. . Thus,
suitably, said polymeric material and filler means are mixed whilst the polymeric material is
molten. Said elevated temperature is suitably below the decomposition temperature of the
polymeric material. Said elevated temperature is preferably at or above the main peak of the
melting endotherm (Tm) for said polymeric material. Said elevated temperature is preferably at
least 300°C. Advantageously, the molten polymeric material can readily wet the filler and/or
penetrate consolidated fillers, such as fibrous mats or woven fabrics, so the composite material
prepared comprises the polymeric material and filler means which is substantially uniformly
dispersed throughout the polymeric material.
The composite material may be prepared in a substantially continuous process. In this
case polymeric material and filler means may be constantly fed to a location wherein they are
mixed and heated. An example of such a continuous process is extrusion. Another example
(which may be particularly relevant wherein the filler means comprises a fibrous filler) involves
causing a continuous filamentous mass to move through a melt or aqueous dispersion
comprising said polymeric material. The continuous filamentous mass may comprise a
continuous length of fibrous filler or, more preferably, a plurality of continuous filaments which
have been consolidated at least to some extent. The continuous fibrous mass may comprise a
tow, roving, braid , woven fabric or unwoven fabric. The filaments which make up the fibrous
mass may be arranged substantially uniformly or randomly within the mass. A composite
material could be prepared as described in PCT/GB2003/001 872, US6372294 or EP1 2 15022.
Alternatively, the composite material may be prepared in a discontinuous process. In
this case, a predetermined amount of said polymeric material and a predetermined amount of
said filler means may be selected and contacted and a composite material prepared by
causing the polymeric material to melt and causing the polymeric material and filler means to
mix to form a substantially uniform composite material.
The composite material may be formed into a particulate form for example into pellets or
granules. Pellets or granules may have a maximum dimension of less than 10mm, preferably
less than 7.5mm, more preferably less than 5.0mm.
Preferably, said filler means comprises one or more fillers selected from glass fibre,
carbon fibre, carbon black and a fluorocarbon resin. More preferably, said filler means
comprises glass fibre or carbon fibre.
A composition or composite material as described may include 20 to 99.9wt% (e.g . 20 to
70wt%) of said polymeric material and 0 .1 to 80wt% (e.g. 30 to 80wt%) of filler means.
Preferred embodiments include greater than 10wt%, more preferably greater than 40wt% of
filler means.
In an especially preferred embodiment, a said polymeric material which is part of a said
composition has a Tm of less than 350°C, preferably less than 330°C, more preferably less
than 3 15°C. Polymeric materials which include repeat units of formula VII I and IX may be
particularly preferred.
The invention extends to a composition or composite material as described per se.
Said polymeric materials may be provided in a pack. Said pack may include at least
1kg , suitably at least 5kg , preferably at least 10kg , more preferably at least 14kg of material of
which at least a part is made up of a said polymeric material. Said pack may include 1000kg
or less, preferably 500 kg or less of said polymeric material. Preferred packs include 10 to 500
kg of said polymeric material.
Material in said pack may be in powder or granular form.
Said pack may comprise packaging material (which is intended to be discarded or reused).
Said packaging material preferably substantially fully encloses said polymeric material.
Said packaging material may comprise a first receptacle, for example a flexible receptacle
such as a plastics bag in which said polymeric material is arranged. The first receptacle may
be contained within a second receptacle for example in a box such as a cardboard box.
In a second aspect of the invention , there is provided a polymeric material comprising a
repeat unit of formula
where t 1 and w 1 independently represent 0 or 1 and v 1 represents 0 , 1 or 2 ;
wherein said polymeric material also includes a phenylethynyl moiety and said polymeric
material includes at least 60 mol% (e.g. 60-99.9 mol%), more preferably at least 68 mol% (e.g.
68-99.9 mol%) of repeat units of formula I , especially such units wherein t 1= 1, v 1=0 and w 1=0.
The polymeric material of the second aspect may include any features of the polymeric
material of the first aspect.
According to a third aspect of the invention, there is provided a process for preparing a
polymeric material for example as described according to the first and/or second aspects, the
process comprising:
(i) selecting one or more monomers arranged to be polymerised to define a
polymeric material comprising a repeat unit of formula
where t 1 and w 1 independently represent 0 or 1 and v 1 represents 0 , 1 or 2 ;
(ii) reacting said one or more monomers in the presence of an ethynyl compound
which includes a phenylethynyl moiety in order to incorporate the ethynyl
compound into the polymeric material.
In relation to the total weight of compounds used in the process and incorporated (at
least in part) into the polymeric material, the sum of the wt% of said one or more monomers,
referred to in point (i), used in the process is preferably at least 95 wt%, more preferably at
least 98 wt%, especially at least 99 wt%. The sum may be in the range 95 to 99.9 wt%,
preferably in the range 98 to 99.9 wt%, more preferably 99 to 99.8 wt%. The wt% of said
ethynyl compound used in the process may be 5 wt% or less, preferably 2 wt% or less, more
preferably 1 wt% or less. The wt% of said ethynyl compound used in the process may be in
the range 0 .1 to 5 wt%, preferably in the range 0 .1 to 2 wt% , more preferably in the range 0.2
to 1 wt%.
The ratio of the total weight of said one or more monomers used in point (i) divided by
the weight of said ethynyl compound referred to in point (ii) is suitably in the range 50 to 200,
for example in the range 90 to 200.
The ratio defined as the number of moles of said ethynyl compound divided by the total
number of moles of other monomers used in the process is suitably in the range 0.001 to
0.005, preferably in the range 0.001 5 to 0.004.
The ratio defined as the number of moles of said ethynyl compound divided by the
number of moles of the monomer which is present in the highest amount in the process may
be in the range 0.001 to 0.01 , preferably in the range 0.002 to 0.008,
In point (i), the method preferably comprises selecting a first monomer which is a
dihydroxy compound and a second monomer which is a dihalocompound. Preferred
dihalocompounds include dichloro and difluoro compounds. In a preferred embodiment, said
first monomer is selected from:
a dihydroxybenzene compound of formula:
and a dihydroxybiphenyl compound of formula
In said preferred embodiment, said second monomer is of formula:
x1
where X1 and X2 independently represent halogen atoms, preferably selected from
chlorine and fluorine atoms. Preferably, X1 and X2 represent fluorine atoms.
Preferably, the sum of the wt% (based on the total wt% of reagents incorporated into the
polymer in the process) of monomers of formulae XX, XI and XXII used in the process is at
least 95 wt%, preferably at least 98% , more preferably at least 99 wt% . The sum may be less
than 99.9 wt%
Preferably, the number of moles of monomers which include chlorine or fluorine atoms
which are polycondensed in the process is at least equal to the number of moles of monomers
which include two hydroxy groups (e.g. compounds XX and XXI). It is especially preferred that
the number of moles of monomers which include chlorine or fluorine atoms (e.g. compound
XXI I) is slightly greater than the number of moles of monomers which include two hydroxy
groups.
Said process is preferably carried out in the presence of a solvent. The solvent may be
of formula
where W is a direct link, an oxygen atom or two hydrogen atoms (one attached to each
benzene ring) and Z and Z', which may be the same or different, are hydrogen atoms or
phenyl groups. Examples of such aromatic sulphones include diphenylsulphone,
dibenzothiophen dioxide, phenoxanthin dioxide and 4-phenylsulphonyl biphenyl.
Diphenylsulphone is a preferred solvent.
The process is preferably carried out under substantially anhydrous conditions. In the
process, the compounds of formulae XX, XXI , XXII and said ethynyl compound are suitably
contacted in the presence of said solvent, especially diphenylsulphone. Polymerisation is
suitably effected at a temperature within the range 150°-400°C.
Said ethynyl compound preferably includes a phenylethynyl moiety as described
according to the first aspect. Preferably, said ethynyl compound comprises said phenylethynyl
moiety which is bonded to a leaving group, which is preferably a halogen atom (e.g . CI and F).
Said ethynyl compound preferably includes a fluorine atom and suitably comprises a said
phenylethynyl moiety bonded to a fluorine atom. Said ethynyl compound is preferably a
fluorophenylethynylbenzophenone and , more preferably, is selected from 4-
fluorophenylethynylbenzophenone and 3-fluorophenylethynylbenzophenone.
According to a fourth aspect of the invention, there is provided a method of making a
component, the method comprising:
(i) selecting a polymeric material as described according to the first aspect (or a
polymeric material as described according to the second aspect);
(ii) melt processing said polymeric material so as to define the component.
Melt processing suitably comprises heating the polymeric material above its Tm
measured as described hereinafter. Said melt processing may comprise extruding or
moulding, for example injection moulding the polymeric material.
The method preferably comprises selecting at least 10g , for example 20g to 1 kg to
make said component. The component may incorporate 10 to 1000g of said polymeric
material.
Said polymeric material selected is preferably in the form of pellets or granules.
During the melt processing of the polymeric material, its molecular weight, suitably
illustrated by its RV, rises, as the phenylethynyl moiety in said polymeric material reacts.
The RV of said polymeric material after said method is suitably higher by at least 0 .1
dL/g compared to the RV of said polymeric material selected in step (i). The ratio of the RV of
the polymeric material in said component, after step (ii), divided by the RV of the polymeric
material selected in step (i) may be at least 1.1 or at least 1.2. Said ratio may be in the range
1.1 to 2 , preferably 1.2 to 1.7.
Advantageously, said polymeric may have substantial crystallinity after step (ii) and/or in
said component. Said polymeric material of said component preferably has a crystallinity of at
least 10%, at least 15% or at least 20% , suitably measured as described in the Examples
which follow. The crystallinity may be in the range 10 to 40%, for example 15 to 35%.
Alternatively, crystallinity may be measured by WAXS as described herein. When
measured by WAXS, said polymeric material of said component may be in the range 10 to
40% , for example 15 to 35%.
The Tm (suitably measured as described herein) of said polymeric material of said
component may be at least 300°C, for example at least 320°C or at least 330°C. Said Tm may
be less than 350°C or less than 340°C.
The Tg (suitably measured as described herein) of said polymeric material of said
component may be in the range 135°C to 160°C, for example in the range 135°C to 150°C
The fact said polymeric material has a Tg and Tm may suggest it is only relatively lightly
cross-linked, for example by reaction of phenylethynyl moieties.
The difference between the Tm of the polymeric material selected in step (i) of the
method and the Tm of said polymeric material after melt-processing is suitably at least 1°C,
preferably at least 2°C, The difference may be less than 10°C. The Tm of said polymeric
material after melt -processing is preferably lower than the Tm before melt-processing.
The difference between the Tg of the polymeric material selected in step (i) of the
method and the Tg of said polymeric material after melt-processing is suitably at least 2°C,
preferably at least 5°C. The difference may be less than 12°C. The Tg of said polymeric
material after melt-processing is preferably higher than the Tg before melt-processing.
The tensile strength of said polymeric material of said component measured as
described herein in accordance with IS0527 may be at least 90 MPa, preferably at least 100
MPa. It may be in the range 100MPa to 125 MPa.
The tensile modulus of said polymeric material of said component measured as
described herein in accordance with IS0527 may be at least 4 GPa, for example in the range
3.5 to 4.5 GPa.
The invention extends to a component made in a method according to the fourth aspect.
According to a fifth aspect, there is provided a component which comprises a polymeric
material which includes a repeat unit of formula I as described in the first aspect, wherein t 1= 1,
w 1=0 and v 1=0, wherein said polymeric material includes greater than 98mol% or greater than
98 wt% of repeat units of formula I , wherein the Tg of said polymeric material is at least 145°C,
preferably at least 146°C, more preferably at least 147°C. The Tm may be less than 343°C,
less than 342°C or less than 341 °C. Said polymeric material may include greater than 99mol%
or greater than 99 wt% of repeat units of formula I,
Any invention describe herein may be combined with any feature of any other invention
described herein mutatis mutandis.
Specific embodiments of the invention will now be described , by way of example.
The following materials are referred to hereinafter:
4-fluorophenylethynylbenzophenone (4-FPEB) - obtained from Nexam Chemicals
3-fluorophenylethynylbenzophenone (3-FPEB) - obtained from Nexam Chemicals
PEEK 90 - refers to polyetheretherketone (PEEK) having MV of 0.09KNsm 2 and RV of
0.76 dL/g obtained from Victrex Manufacturing Ltd.
PEEK 150 - refers to polyetheretherketone (PEEK) having MV of 0 .15KNsm 2 and RV of
0.88 dL/g obtained from Victrex Manufacturing Ltd.
PEEK 450 - refers to polyetheretherketone (PEEK) having MV of 0.45KNsm 2 and RV of
1.21 dL/g obtained from Victrex Manufacturing Ltd.
In general terms, in the processes which follow, polyetheretherketone is produced which
is end-capped with a phenylethynyl-containing moiety in accordance with the reaction scheme
below:
The end-capped material, having a relatively low molecular weight, may be subjected to
a thermal cycle to produce a higher molecular weight material having excellent mechanical
properties, a relatively high level of crystallinity and acceptable Tm and Tg.
Unless otherwise stated, Reduced Viscosity (RV) is measured as described in
Procedure 1.
Procedure 1 - Measurement of reduced viscosity (RV)
RV for the non-cured, cured and injection moulded polymers was measured according
to ASTM D2857-95 on a 1% (w/v) solution of the polymer in concentrated sulphuric acid (98%,
1.84g/cm 3) using an Ubbelohde viscometer (D type) at 25 °C. Polymer powder (I .OOOOg ±
0.0001 g) was dissolved in 100ml ± 0.2ml of concentrated sulphuric acid (98%, 1.84g/cm 3) at
room temperature. The solution was agitated to facilitate dissolution and filtered through a No.
1 sintered funnel before use. RV was calculated as RV = (t1 - tO) / (to x C) where t 1 and to are
the flow times measured for the solution and the solvent respectively and C is the
concentration of the solution in g/dL. The flow time of the solution was measured immediately
after preparation of the solution to avoid sulfonation of the polymer. No correction for kinetic
energy was applied.
A range of end-capped materials were prepared , as described in Examples 1 to 11.
Example 1 - Preparation of 4-FPEB-capped PEEK
To a 500 ml_ flange flask fitted with an air condenser, nitrogen inlet and an overhead
torque stirrer were added 4,4'-difluorobenzophenone (BDF) ( 109.92 g , 0.504 mol),
hydroquinone (HQ) (55.06 g , 0.50 mol), and 4-fluorophenylethynylbenzopheone (4-FPEB)
(0.75 g , 0.0025 mol) and diphenylsulfone (DPS) (224 g). The flask was purged with nitrogen
for 30 mins. The mixture was then heated to 160 °C and a mixture of sodium carbonate (53.26
g , 0.503 mol) sieved through a screen of mesh size dqqmhi and potassium carbonate ( 1 .38 g ,
0.001 mol) was added to the reaction mixture. The temperature was raised to 3 15 °C at 1 °C
min and held at this temperature until the desired torque rise was reached. The required
torque rise was determined from a calibration graph of torque rise versus RV. The reaction
mixture was then poured into a foil tray and allowed to cool, milled and washed with 2L of
acetone and then warm water (40 - 50°C) until the conductivity of the waste water was < 2m .
The resulting polymer powder was dried in an air oven for 16 hours at 130 °C and had RV of
0.89 dL/g
Examples 2 to 6 - Preparation of other end-capped PEEKs
By processes similar to Example 1 other 4-FPEB-capped and 3-FPEB-capped PEEK
polymers were prepared. The type and amount of end capping reagents (and BDF) used were
as detailed in Table 1. Note in each example, the amounts of HQ and DPS were as described
in Example 1.
Table 1
Note: "Cross-linker loading (mole %)" is defined as (moles of end-capping reagent /
moles of BDF) x 100%.
Example 7 - Scale-up of 4-FPEB end-capped PEEK
A 70 litre stainless steel reactor fitted with a lid, stirrer/stirrer guide, nitrogen inlet and
outlet was charged with diphenylsulphone (DPS) (20.5 kg) and heated to 160°C. Once the
diphenylsulfone had fully melted, hydroquinone (HQ) (3.85 kg, 35.00mol) 4 , 4'-
diflurobenzophenone (BDF) (7.73 kg, 35.44mol) and 4-fluorophenylethynylbenzophenone (4-
FPEB) (0.053 kg, 0 .175mol) were charged to the reactor under nitrogen. Dried sodium
carbonate (3.73kg, 35. 18mol) sieved through a screen with a mesh of dqqmhi and potassium
carbonate (0.097 kg, 0.70mol) was added . The contents were then heated to 180°C at 1°C/min
while maintaining a nitrogen blanket and held for 100 minutes. The temperature was then
raised to 200°C at 1°C/min and held for 20 minutes. The temperature was further raised to
3 15°C at 1°C/min and held until the desired molecular weight was reached as determined by
the torque rise of the stirrer. The required torque rise was determined from a calibration graph
of torque rise versus RV. The reaction mixture was poured via a band caster into a water bath,
allowed to cool, milled and washed with 400 litres of acetone and 1000 litres of water. The
resulting polymer powder was dried in a tumble dryer until the contents temperature measured
110°C. The resulting end-capped polymer had RV of 1.00 dL/g.
Examples 8 - 11
By processes similar to Example 7 other 4-FPEB-capped polymers were prepared. The
amount of end capping reagent used was as detailed in Table 2 .
Table 2
Note: In each of Examples 8 to 11, the amount of HQ and DPS were as described in Example
7 . "Cross-linker loading (mole %)" is defined as (moles of end-capping reagent / moles of
BDF) x 100%.
Example 12 - Curing of polymeric materials
Respective dried samples of polymer from examples 1 - 6 were compression moulded
into amorphous films by heating 5g of polymer in a mould at 400° under a pressure of 50bar
producing a film of dimensions 120mm x 120mm with a thickness of 0.2mm. The pressure was
released but the films were maintained between the platens of the press for 2 hours at 400°C
to cure the materials, before being quenched in cold water.
Respective polymers from examples 7 , 8 and 10 were cured by heating samples up to
400°C and holding for 2 hours in a DSC pan according Procedure 2 below.
Polymers from Examples 9 and 11 were injection moulded into test bars using an
injection moulding machine with a tool temperature of 150°C, barrel temperature of 360°C,
nozzle temperature of 390°C, holding pressure of 30bar, injection pressure of 60bar until the
mould was filled then 100bar for 10 seconds. The screwback pressure was 10bar and the
screwback speed 175mm/s. The bars were then cured by placing them in a steel tool which
was then placed between the platens of a hot press at 400°C for 2 hours.
The following further procedures are used to assess properties of materials described
herein:
Procedure 2 - Measurement of Tg, Tm, % crvstallinity
A DSC analysis was undertaken on end-capped polymers made as described in the
examples using a Perkin Elmer Jade system.
An 8mg sample of film from examples 1 - 6 obtained as described in Example 12 , an
8mg sample of polymer powder from examples 7 , 8 and 10 and an 8mg sample shaved from
the injection moulded test bars from examples 9 and 11 were scanned by DSC to determine
Tg and Tm as follows:
Samples were heated up from 30°C to 400°C at 10°C per min, held at 400°C for 1
minute (for examples 1 - 6 , 9 and 11) or 2 hours (examples 7 , 8 and 10) then cooled back
down to 100°C at the same rate. The samples were then re-heated to 400°C at 10°C per min ,
held for 1 minute at 400°C before cooling back again to 30°C.
From the DSC trace from the second heat/cool cycle, the onset of the Tg was obtained
as the intersection of the lines drawn along the pre-transition baseline and a line drawn along
the greatest slope obtained during the transition. The Tm was the temperature at which the
main peak of the melting endotherm reached a maximum.
The Heat of Fusion for melting (AHm) was obtained by connecting the two points at which the
melting endotherm deviates from the relatively straight baseline. The integrated area under the
endotherm as a function of time yields the enthalpy (mJ) of the melting transition; the mass
normalised heat of fusion is calculated by dividing the enthalpy by the mass of the specimen
(J/g). The level of crystallisation (%) is determined by dividing the Heat of Fusion of the
specimen by the Heat of Fusion of a totally crystalline polymer, which for polyetheretherketone
is 130J/g.
Procedure 3 - Gel time
Gel time was measured using a parallel plate rheometer equipped with 25mm plates
with a 2mm gap. A thermal sweep was performed at 400°C over 1 hour and the gel time was
determined by observing the time taken for the phase angle to pass through 45°.
Procedure 4 - Fracture energy density
Fracture toughness testing was carried out on an Instron 3369 testing machine
operating with a 30kN load cell using a notched ASTM impact bar (8mm notch) in accordance
with ASTM D5045-99
Procedure 5 - Tensile testing
Tensile testing was carried out on an Instron 3369 testing machine operating with a
30kN load cell with an extension rate of 5mm per min, 25mm gauge length and 40mm
crosshead separation using a 1BA ISO test bar in accordance with ISO 527. Tensile strength,
tensile modulus and elongation at break were determined.
Results
Properties of cured samples of Examples 1 to 6 polymers are included in Table 3
Table 3
Properties of cured samples of Examples 7 to 10 polymers are included in Table 4 . The
post-cured RV was not measured on Examples 7 , 8 and 10 as films were not prepared. The
samples were cured during the DSC process. Only a small (8mg) sample was used which was
not sufficient for RV measurement. Nonetheless, the results do demonstrate an increase in Tg
and decrease in Tm on curing.
Example Starting Tg post Tm Crystallinity
No. RV cure post (X%)
(dL/g) (°C) cure
(°C)
7 1.00 150 328 20
8 1.14 15 1 3 15 19
10 1.19 150 3 18 2 1
Table 4
Properties of the moulded samples of Examples 9 and 11 were assessed and results
provided in Table 5 .
Table 5
Mechanical properties of moulded samples were assessed and compared to
commercially available PEEK 90, PEEK 150 and PEEK 450 materials. Results are provided in
Table 6 .
Table 6
It will be appreciated from Table 6 , that moulding the example 9 polymer having the
same starting RV as PEEK 90, yields a polymer with properties more like PEEK 150. Similarly,
Example 11, having the same starting RV as PEEK 150, has properties after moulding which
are more like PEEK 450.
Advantageously, it is found that the shear heating and injection moulding process
promotes the majority of the curing of the polymers and thus an increase in RV and improved
properties. A post-cure step (e.g. heating at 400°C for 2 hours) is not found to lead to a
significant further increase in fracture toughness over "as moulded" samples.
Alternative phenylethynyl compounds which may be used as described above for 4-
FPEB include the following:
R = F or CI
It should now be appreciated that the phenylethynyl compounds described can be used
to improve mechanical properties of the polymers described whilst maintaining high levels of
crystallinity. The polymer described may be used to produce thin walled parts by injection
moulding - the relatively low RV polymer will be selected to flow into narrow sections of the
mould; however during the moulding process (and/or thereafter) the RV of the polymer may be
increased, whilst still maintaining substantial crystallinity. Alternatively, relatively low RV
polymers may be used to produce highly-filled compounds. After mixing of the polymers and
fillers, the RV of the polymer may be increased to enhance its physical properties whilst still
retaining high levels of crystallinity.
The invention is not restricted to the details of the foregoing embodiment(s). The
invention extends to any novel one, or any novel combination , of the features disclosed in this
specification (including any accompanying claims, abstract and drawings), or to any novel one,
or any novel combination, of the steps of any method or process so disclosed.

Claims
1. A polymeric material comprising a repeat unit of formula
wherein t 1 and w 1 independently represent 0 or 1 and v 1 represents 0 , 1 or 2 ;
wherein said polymeric material also includes a phenylethynyl moiety and wherein,
preferably, said polymeric material has a Reduced Viscosity (RV) of at least 0.6 dL/g.
2 . A polymeric material according to claim 1, which has an RV of at least 0.8 d/Lg.
3 . A polymeric material according to claim 1 or claim 2 , wherein said phenylethynyl moiety
includes a linking moiety L by means of which it is incorporated into the polymeric material
and/or by means of which it is bonded to the repeat unit of formula I, wherein said linking
moiety includes an aromatic moiety which is bonded directly to the phenylethynyl moiety at an
end opposite to the end of the ethynyl moiety which is bonded to the phenyl moiety of said
phenylethynyl moiety.
4 . A polymeric material according to any preceding claim, wherein said phenylethynyl
moiety is of formula
wherein Ph represents optionally-substituted phenyl, Ph2 represents optionallysubstituted
phenyl and L represents a linking moiety by means of which said phenylethynyl
moiety II is incorporated into the polymeric material and/or by means of which it is bonded to
the repeat unit of formula I .
5 . A polymeric material according to claim 4 , wherein moiety -Ph 2-L1 comprises a
benzophenone moiety.
6 . A polymeric material according to claim 4 or claim 5 , wherein moiety -Ph2-L1 is selected
from the following:
wherein "a" or "b" represent the carbon atom bonded to the repeat unit of formula I and
the atom bonded to the ethynyl carbon atom is selected from "c", "d" and "e"; and
wherein "a" or "b" represent the carbon atom bonded to the repeat unit of formula I and
the atom bonded to the ethynyl carbon atom is atom "c".
7 . A polymeric material according to any preceding claim, wherein said polymeric material
incorporates a phenylethynyl moiety which comprises a moiety of formula
wherein the carbon atom bonded to another atom is atom "
8 . A polymeric material according to any preceding claim, wherein said repeat unit of
formula I has t 1= 1, v 1=0 and w 1=0.
9 . A polymeric material according to any preceding claim, wherein said polymeric material
includes at least 50 mol% of repeat units of formula I.
10 . A polymeric material according to any preceding claim, wherein said polymeric material
is selected from:
a polymer comprising at least 98 mol% and/or comprising at least 98 wt% of a repeat unit of
formula I, wherein t 1= 1, v 1=0 and w 1=0; and
a copolymer which includes a repeat unit of formula
-O-Ph-O-Ph-CO-Ph- VIII
and a repeat unit of formula
-O-Ph-Ph-O-Ph-CO-Ph- IX
wherein Ph represents a phenylene moiety.
11. A polymeric material according to claim 10 , wherein said copolymer includes a repeat
unit of formula
and a repeat unit of formula
wherein said copolymer includes at least 68 mol% of repeat units of formula X.
12 . A polymeric material according to any preceding claim, wherein said polymeric material
includes at least 95 mol% of repeat units of formula I, wherein t 1= 1, v 1=0 and w 1=0 and 5
mol% or less of said phenylethynyl moieties.
13 . A polymeric material according to any preceding claim, wherein said polymeric material
includes moieties of structure
wherein n is an integer which is, on average, at least 18 .
14 . A polymeric material according to any preceding claim, wherein said polymeric material
is part of a composition which includes said polymeric material and a filler means.
15 . A polymeric material according to claim 14 , wherein said polymeric material which is
part of a said composition has a Tm of less than 350°C.
16 . A polymeric material comprising a repeat unit of formula
where t 1 and w 1 independently represent 0 or 1 and v 1 represents 0 , 1 or 2 ;
wherein said polymeric material also includes a phenylethynyl moiety and said polymeric
material includes at least 60 mol% of repeat units of formula I.
17 . A polymeric material according to claim 16 , wherein said polymeric material include any
feature of the polymeric material of any of claims 1 to 15 .
18 . .A process for preparing a polymeric material, the process comprising:
(i) selecting one or more monomers arranged to be polymerised to define a
polymeric material comprising a repeat unit of formula
reacting said one or more monomers in the presence of an ethynyl compound
which includes a phenylethynyl moiety in order to incorporate the ethynyl
compound into the polymeric material.
19 . A process according to claim 18 , wherein in relation to the total weight of compounds
used in the process and incorporated into the polymeric material, the sum of the wt% of said
one or more monomers, referred to in point (i), used in the process is at least 95 wt% ,
20. A process according to claim 18 or claim 19 , wherein the ratio of the total weight of said
one or more monomers used in point (i) divided by the weight of said ethynyl compound
referred to in point (ii) is in the range 50 to 200.
2 1. A method of making a component, the method comprising :
(i) selecting a polymeric material as described in any of claims 1 to 17 ; and
(ii) melt processing said polymeric material so as to define the component.
22. A method according to claim 2 1, wherein the RV of said polymeric material after said
method is higher by at least 0 .1 dL/g compared to the RV of said polymeric material selected
in step (i).
23. A method according to claim 2 1 or claim 22, wherein said polymeric material of said
component has a crystallinity of at least 20%.
24. A method according to any of claims 2 1 to 23, wherein the difference between the Tm of
the polymeric material selected in step (i) of the method and the Tm of said polymeric material
after melt-processing is at least 1°C; and the difference between the Tg of the polymeric
material selected in step (i) of the method and the Tg of said polymeric material after meltprocessing
is at least 2°C.
25. A component which comprises a polymeric material which includes a repeat unit of
formula I as described in any of claims 1 to 17 , wherein t 1= 1, w 1=0 and v 1=0, wherein said
polymeric material includes greater than 98mol% or greater than 98 wt% of repeat units of
formula I , wherein the Tg of said polymeric material is at least 146°C.