METHODS OF PREPARING NOVEL HALIDE ANION FREE QUATERNARY
AMMONIUM SALT MONOMERS, POLYMERIZATION METHODS
THEREFOR, AND METHODS OF USE OF THE RESULTING POLYMERS
FIELD OF USE
[0001] The present invention pertains to methods for making chloride free
Quaternary Ammonium Salt Monomers, Polymers prepared from the Monomers, and
Methods of Using the Polymers in water treatment processes such as for use as
flocculants and coagulants in water treatment.
BACKGROUND OF THE INVENTION
[0002] Water clarification is well known throughout a number of industries.
Various physical means have been used to remove particulate matter dispersed in a
bulk liquid phase. Examples of common particulate separation techniques include
filtration, settling, desalting, electrochemical techniques, centrifugation, flotation, and
the like. Such separation processes can often be made more efficient by the use of
coagulating and flocculating agents.
[0003] Coagulation may be defined as the stabilization of colloids by
neutralizing the forces that keep the colloidal particles dispersed or separated from
each other in the wastewater. Cationic coagulants are often used to provide positive
electrical charges to the colloidal particles to neutralize the negative charge on the
particles. As a result, the particles collide to form larger particles called floes.
Flocculation, on the other hand, refers to the action of polymeric treatments in the
formation of bridges between the floes to thereby form large agglomerates or clumps.
Anionic and cationic polymers are commonly employed as flocculants to agglomerate
the floes so that the agglomerates will float and not settle. Once suspended in the
wastewater, they can be removed via sedimentation, filtration, or other separation
techniques.
[0004] Commonly employed cationic coagulants such as those based on
polydiallyldimethylammonium chloride (PDADMAC) are disclosed for example in
U.S. Patent 3,288,770. Additionally, cationic copolymers such as those based on
acrylamide copolymers with cationic repeat units such as quaternary ammonium
acrylates dimethylaminoethylacrylate methyl chloride (AETAC) or
dimethylaminoethylmethacrylate methyl chloride (METAC) are often used.
[0005] In those situations in which quaternary ammonium salt moieties are
present in polymers that are employed as cationic coagulants, the anionic counter ion
to the cationic nitrogen is often a chloride ion. These chloride ions are corrosive, and
when excessive amounts of same are found in the wastewater, corrosion of metal
surfaces in contact with the water can occur.
[0006] Additionally, environmentally based requests to limit the amount of
total dissolved solids (TDS) present in effluents have been increasing over the years.
Inorganic ions that are measured as part of the TDS discharge include chloride ions.
Many industries and municipal wastewater facilities must comply then with new TDS
standards; thus raising concern for chloride content in such discharge. TDS also
presents an issue for water reuse of treated wastewater.
SUMMARY OF THE INVENTION
[0007] In one exemplary embodiment, a method is provided for forming
diallyldialkylammonium anion monomer wherein diallyldialkylammonium chloride is
reacted with an anion contributing metathesis agent in an aqueous solution to yield a
precipitate and diallydialkylammonium anion. The method further comprises
removing the precipitate from solution. In accordance with another aspect of the
invention, the anion contributing metathesis agent is a member selected from the
group consisting of potassium acetate, potassium methanesulfonate, and potassium
acrylate. In accordance with another exemplary embodiment, the precipitate is
potassium chloride.
[0008] In another embodiment, a non-chloride containing quaternary
ammonium salt anion monomer is formed from a quaternary ammonium salt chloride
precursor. The method comprises reacting the precursor with an anion metathesis
agent in an aqueous medium to yield a precipitate and the non-chloride containing
quaternary ammonium salt anion monomer. The precipitate is then removed from the
reaction medium.
[0009] In another embodiment, the quaternary ammonium salt chloride
precursor has the formula
Rl
CHs-CH
Q
R2
R4-N +-R3
R5 A
wherein Rl is H or CH3; Q is -C(0)0-, -OC(O)-, or —C(0)NH— ; R2 is
branched or linear (C1-C4) alkylene; R3, R4, and R5 are independently chosen from
H, C1-C4 linear, cyclic or branched alkyl or alkylene, or an Cs-Cs aromatic group or
alkylaromatic group, N+ R3 R4 R5 can also be a cyclic system, A= Cl .
[0010] Another embodiment of the invention pertains to the novel monomer
diallydimethylammonmm acetate and its preparation. Another aspect of the invention,
pertains to the novel polymer polydiallyldimethylammonium acetate and its
preparation.
[0011] In still further embodiments, methods for clarifying wastewater
comprise adding to the wastewater a polydiallyldimethylammonium acetate. The
wastewater may, for example, be oily wastewater from the food and beverage, steel,
automotive, transportation, refinery, pharmaceutical, metals, paper and pulp,
chemical processing and hydrocarbon processing industries. In still further
environments, methods for clarifying water comprise adding to the water a polydiallyl
dimethyl ammonium acetate. The water may be raw water from lakes, streams,
wells, ponds and rivers.
DETAILED DESCRIPTION
[0012] In one exemplary embodiment of the invention, a novel monomer,
diallydimethyl ammonium acetate (DADMOAC) is made based upon the metathesis
reaction between potassium acetate and diallydimethyllammonium chloride
(DADMAC). The high solubility of DADMOAC vs. KC1 forces the latter compound
to be precipitated in quantitative yields. Simple filtration leads to formation of the
novel monomer, (DADMOAC) and solid KC1. In another aspect of the invention, the
novel monomer can be polymerized by known free radical techniques to yield
polydiallyldimethylammonium acetate (PDADMOAC).
[0013] In one embodiment, the DADMOAC can be prepared by one of two
similar methods. The first method involves mixing of commercially available
DADMAC monomer ( «65%) with powdered potassium acetate to lead to the
quantitative precipitation of KC1. Simple filtration of the resulting solution yields the
DADMOAC monomer.
[0014] In an alternative synthetic route, the potassium acetate is prepared by
neutralization of potassium hydroxide solution ( 50%) by acetic acid ( ~ 99%) . The
resulting potassium acetate is then reacted with the DADMAC solution ( «65%) at
room temperature. After about two hours, the complete precipitation of KC1 is
effected. The DADMOAC monomer is isolated from the precipitate by simple
filtration under reduced pressure. In some experiments to date, the yield of «68%
solution of DADMOAC is quantitative > 98-99% .
[0015] One general procedure for preparing Cl free monomers and polymers
from DADMAC is as follows:
+ KCl Precipitate
CI CH3C(O)O-
5 % Solution in Water
Filtration of KCI
(Commercial Monomer)
i) :
ii).
Azo Initiator, etc.)
CH3C(O)O[
0016] Another exemplary procedure follows the route:
KCl l Precipitate
5 % Solution in Water
Filtration of KCI
(Commercial Monomer)
Methanesulfonic or Acrylic Acid,
~ 50 % KOH solution, 1hr, RT
MeSO3- or CH2=CHC(O)OAzo
Initiator, etc.)
MeSO3- or CH2=CHC(O)O[
0017] The isolated monomer, or aqueous solution containing such monomer,
can be polymerized by traditional free radical techniques such as those reported in
U.S. Patent 3,288,770, incorporated by reference herein. For example, temperature
ranges for the polymerization may vary between about 0-100 °C for a period of from
about 1-72 hours. The monomer concentrate in the reaction medium may be within
the range of 5-70% with concentrations of between about 50-70 wt% being preferred.
[0018] Water is the generally preferred reaction solvent, but other solvents
may also be employed such as methanol, ethanol, dimethyl formamide, diethyl
formamide, dimethyl acetamide, acetonitrile, dimethoxyethane, etc. Catalyst
(initiator) concentrations from about 0.05% - 5.0% (based on monomer weight) and
0. 1-1.0% may be mentioned as exemplary.
[0019] As to the initiators that may be employed, peroxide initiators such as
dicumyl peroxide, t-butylhydroperoxide, acetyl peroxide, and benzoyl peroxide may
be used. Azo based initiators such as azoisobutyronitrile are also effective, and
persulfate initiators such as sodium or potassium persulfate may also be mentioned.
[0020] The use of an anion contributing metathesis agent such as potassium
acetate to synthesize the Cl anion free quantitative monomer provides a simple and
direct reaction route. As is known in the art, metathesis refers to a molecular process
involving the exchange of bonds between two reacting chemical species which results
in the creation of products with similar or identical bonding affinities. Here, the
metathesis reaction occurs between the Cl anion and substitute anion such as the
acetate ion from potassium acetate. In the reaction, the acetate replaces or substitutes
for the CI ion associated with the quaternary nitrogen compound. The resulting KC1
precipitates from the reaction medium.
[0021] As used herein, the phrase "anion contributing metathesis agent" refers
to a compound in which the anionic portion thereof will substitute for or replace the
Cl ion from the quaternary ammonium moiety. Although potassium acetate is
clearly preferred, potassium acrylate and potassium methane sulfonate may also be
mentioned as exemplary anion contributing metathesis agents since, when these are
employed in the reaction, the acrylate anion and methosulfonate anion replace the Cl
ion from the quat.
[0022] In addition to providing replacement of the Cl anion from DADMAC
type quaternary ammonium salt compounds (Quats), the reaction can be employed to
substitute a more environmentally acceptable anion to a multiplicity of varying CI
containing quats. For instance, although some of the specific examples involve
reaction of the popular DADMAC quat, other diallyldialkylammonium chlorides shall
similarly react. (The alkyl groups may, for example, be from Ci-Ce alkyl).
Additional tests with acryloyl and acrylamido quats result is similar substitution of
acrylate, methosulfate, and acetate anions for the chloride anion in precursor quats.
[0023] For example, the general metathesis reaction can be utilized to
substitute anions from monomeric precursors having the formula:
Formula I
Rl
CHs-CH
Q
R2
R4-N +-R3
R5 A
wherein Rl is H or CH3; Q is -C(0)0-, -OC(O)-, or —C(0)NH— , R2 is
branched or linear (C1-C4) alkylene; R3, R4, and R5 are independently chosen from
H, C1-C4 linear, cyclic, or branched alkyl or alkylene, or an Cs-Cs aromatic group or
alkylaromatic group; N+ R3 R4 R5 can also be a cyclic system, A= C 1 . Exemplary
monomers encompassed by Formula I above include:
AETAC = 2-acryloxyethyltrimethyl ammonium chloride
MAPTAC = 3-(meth) acrylamidopropyl trimethyl ammonium chloride
METAC = 2-methacryloxyethyltrimethyl ammonium chloride
These monomers can readily be converted to acetate, methosulfate, or acrylate counter
ion form.
[0024] The general procedure for preparing Cl free monomers from Formula
I type quats is as follows:
KCl Precipitate
~ 65 % - 80 % Solution in Water
C
R
R
)Oiii)
. Dilution at Desired Concentration
iv) . Polymerization at 70 - 80 °C (SPS, Azo Initiator, etc.)
CI- Free Poly(METAC), Poly(AETAC), etc.
[0025] The polymers produced from the chloride free quaternary ammonium
salt monomers may be employed as coagulants for treating wastewater. In this
regard, the polymers may be fed in an amount of from 0.5-500 ppm; 0.25-100 ppm;
0.5-75 ppm, or from 1-50 ppm to the wastewater based on one million parts of said
wastewater. The wastewater is generally primary or secondary wastewater including
oily wastewater from the food and beverage, steel, automotive, transportation,
refinery, pharmaceutical, metals, pulp and paper, chemical processing, or
hydrocarbon processing industries. The polymer may also be fed in the dosage range
of 0.5-500 ppm to clarify raw water from rivers, lakes, ponds, streams, wells, and
aquifers.
EXAMPLES
Example 1 - Diallydimethylammonium acetate monomer preparation (DADMOAC) -
Protocol A
[0026] 200 g of (0.804 mol) of -65% commercially available
diallyldimethylammonium chloride (DADMAC) and 79.49 g of potassium acetate
(0.806 mol) (-99.5%) were mixed in a chemical reaction flask. The heterogeneous
mixture was heated at about 80 °C while agitated for at least 60 minutes. The
resulting reaction mixture was then cooled to 25 °C, and after 120 minutes, the
reaction mixture was filtered under reduced pressure at 25 °C.
[0027] KC1 precipitate was filtered from the reaction mixture with
approximately 217. 1 g of DADMOAC remaining in the solution water with
DADMOAC being present in an amount of -68% solution in water resulting in about
148.8 g (-0.804 mol) of DADMOAC. DADMOAC yield was about 99%. 60.2 g of
KC1 was separated from the reaction mixture (theoretical -59.8 g).
[0028] 30 g of DI water was added to the DADMOAC aqueous solution in
order to delete the solution to about 60% actives DADMOAC. The pH of this 60%
solution was about 8.34 (25 °C).
Example 2 - DADMOAC monomer preparation - Protocol B
[0029] 192.9 DADMAC (-67.6%) solution (0.804) mole and 48.7 g (0.804
mol) glacial acetate acid were charged into a reaction flask and stirred at 25 °C. In a
separate flask, 51.80 g (0.804 mol) KOH pellets (-86.9%) were mixed with 48.2 g DI
water. The first reaction flask containing DADMAC and glacial acetic acid was
cooled to about 15-20 °C.
[0030] The KOH solution from the second flask was added to the first flask
over a period of about 120 minutes with the resulting reaction mixture in the first
flask subjected to intense agitation. The temperature of the reaction mixture in the
first flask was carefully monitored so as not to exceed 80 °C. Upon completion of
the addition of the KOH solution to the first flask, this reaction mixture was then
heated to about 90-100 °C in order to evaporate 62.7 g water. The reaction mixture
was then cooled to 25 °C and allowed to stand at this temperature for 120 minutes.
The reaction mixture was then filtered under reduced pressure in order to remove
KC1. The yield of KC1 salt after drying was «60.39 (theoretical 59.9 g), and the
yield of DADMAOC solution was about 217.7 g -99% (theoretical «218.4 g).
The resulting DADMOAC solution had a pH of about 8.95 (25 °C), and the active
DADMOAC concentration in solution was 60% in water. 29 g of DI water was
added to the DADMOAC solution in order to dilute the solution to a 60%
DADMOAC actives concentration. The pH of this 60% solution was -8.29 (25 °C).
Example 3 - Radical Polymerization of DADMOAC Monomer (-60% in water) using
Potassium Persulfate Initiator
[0031] An aqueous solution containing 115 g DADMOAC monomer (60%
solution) was charged into a reactor under agitator on condition. The solution was
heated to 80 °C and sparged with nitrogen for 20-30 minutes. Potassium Persulfate
(SPS) (0.5 g) was dissolved in 2.0 g of DI water in order to form an initiator solution.
The initiator solution was fed to the DADMOAC solution for 120 minutes at 120 °C.
[0032] Agitation of the reaction solution was continued for 60 minutes at
80°C. After addition of the initiator, a shot of 1. 1 g SPS and 3.0 g DI water was
prepared, mixed and sparged with nitrogen for 2-3 minutes. This additional shot of
initiator was then shot fed to the reaction mixture in order to polymerize residual
monomer. The reaction mixture was heated to 85 °C and maintained under agitation
at this temperature for 90 minutes. After this reaction was completed, the reaction
was cooled to 25 °C. 54.0 g DI water was added for dilution, and the reaction
mixture was then agitated for an additional 30 minutes.
[0033] The resulting polymer solution was obtained:
pH = 6.61 (25 °C)
Solids = 44.25%
Viscosity = 1600 cps (LV3, 30 rpm @ 25 °C)
Mw (GPC) = 48,600
Mw/Mn (GPC) = 4.05
MW and Mn are determined by GPC using calibration based on the narrow Mw/Mn
polyethyleneoxide standards.
Example 4 - Radical Polymerization of DADMOAC Monomer (-55 % in water) -
SPS Initiator
[0034] An aqueous solution containing 125 g DADMOAC monomer (55%
solution) was charged into a reactor under agitator on conditions. The solution was
heated to 80 °C and sparged with nitrogen for 20-30 minutes. SPS (0.75 g) was
dissolved in DI water (2.09) in order to provide an initiator solution. This initiator
solution was fed to the DADMOAC solution over a period of 120 minutes while the
reaction mixture was maintained at 120 °C with a continuous agitation. After the
initiator addition was over, the reaction mixture was agitated for an additional 60
minutes at 80 °C. A burnout shot of initiator solution was prepared by mixing 1.5 g
SPS in 3.5 g DI water under nitrogen sparging conditions for 2-3 minutes. This
burnout shot initiator was added to the reaction mixture, with the reaction mixture
being heated to 85 °C, under agitation, for 90 minutes. After the reaction was over,
the reaction mixture was cooled to 25 °C. Dilution water in an amount of 40.0 g DI
was added while the mixture was agitated for an additional 30 minutes.
[0035] The resulting polymer solution was obtained:
pH = 6.45 (25 °C)
Solids = 43.50%
Viscosity = 1200 cps (LV3, 30 rpm @ 25 °C)
Mw (GPC) = 39,000
Mw/Mn (GPC) = 3.98
Mw and Mn are determined by GPC using calibration based on the narrow Mw/Mn
polyethyleneoxide standards.
Example 5 - Monomer Synthesis:
([2-(methacryloyl) ethyl]-trimethylammonium aerylate) - METAC/ Aerylate
[0036] 221.30 g (0.847 mol) of METAC (-79.5% solution in water) and 61.6
g (0.847 mol) acrylic acid (-99%) were charged into a reaction flask. The resulting
solution was agitated for 10 minutes and cooled down at 10-15 °C. 54.7 g (0.847
mol) KOH (-86.9%) was dissolved in 33.3 g DI water with the resulting KOH
solution cooled to about 20 °C. The KOH solution was added to the METAC/acrylic
acid solution over a period of 120 minutes while the temperature was maintained
below 40 °C to avoid spontaneous polymerization. After termination of the KOH
solution addition, the mixture was stirred continuously for 120 minutes at 25 °C. KC1
formed as a solid precipitate and was separated from the reaction medium by filtering
under reduced pressure. The yield of KC1 was 66.7 g (theoretical 63. 10 g) with the
yield of METAC/acrylate being 297.36 g -96.7% (theoretical 307.8 g).
[0037] The pH of the METAC/Acrylate solution was 6.67 (25 °C), and the
solids content of the METAC/acrylate in solution was about 66.9%.
Example 6 - Monomer Synthesis
([2-(Acryloyl) ethyl] - trimethylammonium (aerylate) - AETAC/Acrylate
[0038] 216.0 g (0.847 mol) AETAC (-75.9% solution in water) and 61.6 g
(0.847 mol) Acrylic Acid (-99%) were charged into a reaction flask. The resulting
solution was agitated for 10 minutes and cooled down at 10-15 °C. In a separate
flask, 54.7 g (0.847 mol) KOH (-86.9%) was mixed in 33.3 g DI water. The KOH
solution was cooled to 20 °C and then added to the AETAC/ Acrylic Acid mixture
over a period of 120 minutes. Temperature of the reaction mixture was maintained
below 40 °C to avoid spontaneous polymerization. After termination of the KOH
solution, the reaction mixture was continuously stirred for a period of 120 minutes
while the temperature was maintained at 25 °C. KC1 formed as a solid precipitate and
was separated from the reaction mixture under reduced pressure to yield
AETAC/Acrylate in solution. The yield of KC1 was 69.60 g (theoretical 63. 10 g)
with the yield of AETAC/Acrylate solution being 279.05 g, -92.2% (theoretical
302.50 g). The pH of the AETAC/Acrylate solution was 6.61 (25 °C) with a solids
content of about 69.50% AETAC/acrylate in solution.
Example 7
[0039] In order to demonstrate the efficacy of the DADMOAC polymers in
reducing turbidity in sample wastewaters, the following tests were undertaken.
[0040] Jar tests were undertaken to evaluate water clarification efficacy of the
coagulants. 600 ml beakers were filled with the sample wastewater. The desired
coagulant dosage was then added to each beaker with the beakers stirred with paddles
first at 100 rpm and then 35 rpm for a total stirring time of 7 minutes. The beakers
were allowed to settle for 5 and then 30 ml of supernatant from each beaker was
removed via syringe. The supernatant samples were then measured with a HACH
2100 AN Tubidimeter set to the NTU (nephlelometric turbidity unit) measurement
mode.
[0041] Results are shown in Table 7. 1.
Table 7.1
Standard LNVA River Water Standard Jar Tests
Raw NTU = 93
pH = 7(+ 1-0.2)
C-l = polyDADMAC
A-l = polyDADMOAC - made in accordance with Example 4; molecular weight
39,100 Mw/Mn = 3.98
A-2 = polyDADMOAC - made in accordance with Example 3; molecular weight
48,600 Mw/Mn 4.05
A-3 = polyDADMOAC - made in accordance with Example 3 except that initiator
feed time was 90 minutes, Mw = 44,900 Mw/Mn 3.90
[0042] While typical embodiments have been set forth for the purpose of
illustration, the foregoing descriptions should not be deemed to be a limitation on the
scope of the appended claims. It is apparent that numerous other forms and
modifications of this invention will occur to one skilled in the art. The appended
claims and these embodiments should be construed to cover all such obvious forms
and modifications that are within the true spirit and scope of the present invention.

CLAIMS
1. Method of forming diallyldialkylammonium anion monomer comprising
reacting diallyldialkylammonium chloride and an anion contributing metathesis agent
in an aqueous solution to yield a precipitate and diallyldialkylammonium anion, and
removing said precipitate from said solution.
2. Method as recited in claim 1 wherein said anion contributing metathesis
agent is a member selected from potassium acetate, potassium methanesulfonate, and
potassium aery late, said precipitate being KC1.
3. Method as recited in claim 2 wherein said anion contributing metathesis
agent is potassium acetate, said diallyldialkylammonium chloride is
diallyldimethylammonium chloride and said diallyldialkylammonium anion monomer
is diallyldimethylammonium acetate monomer.
4. Method as recited in claim 2 wherein said KC1 is filtered to remove it
from said solution.
5. Method of forming a nonchloride containing quaternary ammonium salt
anion monomer from a quaternary ammonium salt chloride precursor, said method
comprising reacting said precursor with an anion metathesis agent in an aqueous
medium to yield a precipitate and said nonchloride containing quaternary ammonium
salt anion monomer, and removing said precipitate from said aqueous medium.
6. Method as recited in claim 5 wherein said precursor is
diallyldialkylammonium chloride, said anion metathesis agent being selected from
potassium aery late, potassium methansulfonate, and potassium acetate, said precipitate
being KC1.
7. Method as recited in claim 6 wherein said precursor is
diallyldimethylammonium chloride, said anion metathesis agent being potassium
acetate, and said nonchloride containing ammonium salt monomer is
diallyldimethylammonium acetate (DADMOAC).
8. Method as recited in claim 5 wherein said quaternary ammonium salt
chloride precursor has the formula
Formula I
Rl
CHs-CH
Q
R2
R4-N +-R3
R5 A
wherein Rl is H or CH3; Q is -C(0)0-, -OC(O)-, or —C(0)NH— ; R2 is
branched or linear (C1-C4) alkylene; R3, R4, and R5 are independently chosen from
H, C1-C4 linear, cyclic or branched alkyl or alkylene or an Cs-Cs aromatic group or
alkylaromatic group N+ R3 R4 R5 can also be a cyclic system, A= Cl , said anion
metathesis agent being selected from potassium aerylate, potassium methanesulfonate,
and potassium acetate, said precipitate being KC1.
9. Method as recited in claim 8 wherein in said Formula I , Rl is H, Q is
-C(0)0-, R2 is Et, and R3, R4 and R5 are all Me - (AETAC).
10. Method as recited in claim 8 wherein in said Formula I , Rl is CF , Q
is —C(0)(0)— , R2 is Et and R3, R4, and R5 are all Me - (METAC).
11. Diallyldimethylammonium acetate
12. Polydiallydimethylammonium acetate
13. Polydiallydimethylammonium acetate as recited in claim 12 having a
molecular weight of about 5,000 to about 2,000,000.
14. A method for clarifying water comprising adding to said water a
coagulant in the amount of about 0.25-500 ppm based upon one million parts of said
water, said coagulant being polydiallyldimethylammonium acetate (PDADMOAC).
15. A method as recited in claim 14 wherein said water is raw, untreated
water from a lake, river, pond, stream or aquifer.
16. A method as recited in claim 14 wherein said water is wastewater.
17. A method as recited in claim 16 wherein about 0.5-75 ppm of said
PDADMOAC is added to said wastewater.
18. A method as recited in claim 17 wherein about 1 to about 50 ppm of
said PDADMOAC is added to said wastewater.
19. A method as recited in claim 16 wherein said wastewater is oily
wastewater from food and beverage, steel, automotive, transportation, refinery,
pharmaceutical, metals, paper and pulp, chemical processing, and hydrocarbon
processing industries.
20. A method as recited in claim 19 wherein said PDADMOAC has a
molecular weight of between about 5,000 to 2,000,000.