GRAFT POLYARYLETHER COPOLYMERS

Abstract

The invention relates to a graft polyarylether (PAE) copolymer (P1), a process for preparing the graft PAE copolymer (P1) from a side-chain allyl/vinylene-functionalized PAE copolymer (P0) via free radical polymerisation with at least one betaine methacrylate or acrylate (B(m)A) vinyl monomer and optionally further with vinyl pyrrolidone (VP), and the use of the graft PAE copolymer (P1) in the preparation of an article, such as a membrane or a part thereof. The graft PAE copolymer (P1) comprises at least two types of recurring units, one of which having side-chain grafted poly(B(m)A) homopolymers or poly(B(m)A-VP) copolymers. The PAE copolymer (P0), from which the graft PAE polymer (P1) is prepared, may be an amorphous side-chain allyl/vinylene-functionalized polyaryletherketone or polyarylethersulfone copolymer.

Claims

1. A graft polyarylether (PAE) copolymer (P1) comprising: collectively at least 50 mol. % of sulfone recurring units (R.sub.P1a) of formula (M1) and functionalized sulfone recurring units (R*.sub.P1a) of formula (N1), said mol. % being based on the total number of moles of recurring units in the graft PAE copolymer (P1): ##STR00040## or collectively at least 50 mol. % of ketone recurring units (R.sub.P1b) of formula (M2) and functionalized ketone recurring units (R*.sub.P1b) of formula (N2), said mol. % being based on the total number of moles of recurring units in the graft PAE copolymer (P1): ##STR00041## wherein the molar ratio of sulfone recurring units (R.sub.P1a)/recurring units (R*.sub.P1a) or ketone recurring units (R.sub.P1b)/recurring units (R*.sub.P1b) is at least 1/5 and at most 100/1; and wherein each R.sub.1 is independently selected from the group consisting of a halogen, alkyl, alkenyl, alkynyl, aryl, ether, thioether, carboxylic acid, ester, amide, imide, alkali or alkaline earth metal sulfonate, alkyl sulfonate, alkali or alkaline earth metal phosphonate, alkyl phosphonate, amine and quaternary ammonium; each i is independently 0 or an integer from 1 to 4, preferably i=0 or 1; T is selected from the group consisting of a bond; C(CH.sub.3).sub.2; SO.sub.2; O; S; C(O); C(CF.sub.3).sub.2; C(CCl.sub.2); C(CH.sub.3)(CH.sub.2CH.sub.2COOH); NN; and R.sub.aCCR.sub.b, where each R.sub.a and R.sub.b, independently of one another, is a hydrogen or a C1-C12-alkyl, C1-C12-alkoxy, or C6-C18-aryl group; (CH.sub.2).sub.m and (CF.sub.2).sub.m with m being an integer from 1 to 6; an aliphatic divalent group, linear or branched, of up to 6 carbon atoms; and combinations thereof; G.sub.N is selected from the group consisting of the following formulae (G.sub.N1) to (G.sub.N10) and any combinations thereof: ##STR00042## ##STR00043## ##STR00044## wherein W in the group G.sub.N is selected from the group Consisting of a bond, C(CH.sub.3).sub.2, SO.sub.2, and any combination thereof; each k in the group G.sub.N is independently 0 or an integer from 1 to 4; the two grafted zwitterionic polymers P.sub.2 in the group G.sub.N, being the same or different from each other, comprise betaine (meth)acrylate-based (co)polymers [pB(m)A] selected from the group consisting of poly(sulfobetaine (meth)acrylate)s [pSB(m)A], poly(carboxybetaine (meth)acrylate)s [p(CB(m)A], poly(phosphobetaine (meth)acrylate)s [pPB(m)A], copolymers derived from vinyl pyrrolidone and at least one betaine (meth)acrylate [pB(m)A-VP] and any combination thereof; and the two I in the group G.sub.N, being the same or different from each other, represent a fragment of a free radical initiator and/or a fragment of betaine (meth)acrylate-based (co)polymer [pB(m)A].

2. The graft polyarylether copolymer (P1) of claim 1, wherein the sulfone recurring units (R.sub.P1a) is of formula (M1a), (M1b), or (M1c): ##STR00045## wherein each R.sub.1 is independently selected from the group consisting of a halogen, alkyl, alkenyl, alkynyl, aryl, ether, thioether, carboxylic acid, ester, amide, imide, alkali or alkaline earth metal sulfonate, alkyl sulfonate, alkali or alkaline earth metal phosphonate, alkyl phosphonate, amine and quaternary ammonium; each i is independently 0 or an integer from 1 to 4, preferably i=0 or 1.

3. The graft polyarylether copolymer (P1) of claim 1, wherein i is zero for each R.sub.1.

4. The graft polyarylether copolymer (P1) of claim 1, wherein the ketone recurring units (R.sub.P1b) is of formula (M2a): ##STR00046##

5. The graft polyarylether copolymer (P1) of claim 1, comprising collectively at least 80 mol. % of sulfone recurring units (R.sub.P1a) and (R*.sub.P1a) or ketone recurring units (R.sub.P1b) and (R*.sub.P1b), said mol. % being based on the total number of moles of recurring units in the graft PAE copolymer (P1).

6. The graft polyarylether copolymer (P1) of claim 1, wherein k is 0 in the group G.sub.N of recurring units (R*.sub.P1a) or (R*.sub.P1b).

7. The graft polyarylether copolymer (P1) of claim 1, wherein the molar ratio of sulfone recurring units (R.sub.P1a)/recurring units (R*.sub.P1a) or ketone recurring units (R.sub.P1b)/recurring units (R*.sub.P1b) is from 1/4 to 50/1.

8. (canceled)

9. The graft polyarylether copolymer (P1) of claim 1, wherein each of the grafted polymer P.sub.2 in any of the formulae (G.sub.N1) to (G.sub.N10) in the recurring units (R*.sub.P1a) or (R*.sub.P1b) comprises more than 50 mol. %, based on the total number of recurring units of the grafted polymer P.sub.2, of recurring units Rzw selected from the units of formulae (Pas.sup.1), (Pas.sup.2), (Pac.sup.1) and/or (Pac.sup.2): ##STR00047## wherein m in the alkylene chain (CH.sub.2).sub.m is an integer from 1 to 20; q in the alkylene chain (CH.sub.2).sub.q is an integer from 1 to 20; and the number of recurring units Rzw of formulae (Pas.sup.1), (Pas.sup.2), (Pac.sup.1) and/or (Pac.sup.2) in the grafted zwitterionic polymers P.sub.2 is from 3 to 200.

10. The graft polyarylether copolymer (P1) of claim 1, not being crosslinked.

11. A process for preparing the graft polyarylether copolymer (P1) of claim 1, comprising: reacting, in a solvent S.sub.1, a side-chain allyl/vinylidene-functionalized polyarylether copolymer (P0), with at least one vinyl monomer selected from betaine (meth)acrylates or a combination of at least one betaine (meth)acrylate and vinyl pyrrolidone, in the presence of at least one free radical initiator, to form the graft PAE copolymer (P1) comprising grafted zwitterionic (co)polymers P.sub.2; and removing any free ungrafted (co)polymers resulting from free radical polymerisation and optionally any unreacted vinyl monomer and/or unreacted free radical initiator from the formed graft PAE copolymer (P1) to generate a purified the graft PAE copolymer (P1), wherein the allyl/vinylidene-functionalized polyarylether copolymer (P0) comprises: collectively at least 50 mol. % of sulfone recurring units (R.sub.P0a) of formula (M1) and functionalized sulfone recurring units (R*.sub.P0a) of formula (N0), said mol. % being based on the total number of moles of recurring units in the copolymer (P0): ##STR00048## or collectively at least 50 mol. % of ketone recurring units (R.sub.P0b) of formula (M2) and functionalized ketone recurring units (R*.sub.P0b) of formula (N0), said mol. % being based on the total number of moles of recurring units in the copolymer (P0): ##STR00049## wherein each R.sub.1 is independently selected from the group consisting of a halogen, alkyl, alkenyl, alkynyl, aryl, ether, thioether, carboxylic acid, ester, amide, imide, alkali or alkaline earth metal sulfonate, alkyl sulfonate, alkali or alkaline earth metal phosphonate, alkyl phosphonate, amine and quaternary ammonium; each i is independently 0 or an integer from 1 to 4, preferably i=0 or 1; T is selected from the group consisting of a bond; C(CH.sub.3).sub.2; SO.sub.2; O; S; C(O); C(CF.sub.3).sub.2; C(CCl.sub.2); C(CH.sub.3)(CH.sub.2CH.sub.2COOH); NN; and R.sub.aCCR.sub.b, where each R.sub.a and R.sub.b, independently of one another, is a hydrogen or a C1-C12-alkyl, C1-C12-alkoxy, or C6-C18-aryl group; (CH.sub.2).sub.m and (CF.sub.2).sub.m with m being an integer from 1 to 6; an aliphatic divalent group, linear or branched, of up to 6 carbon atoms; and combinations thereof; G.sub.P is selected from the group consisting of at least one of the following formulae (G.sub.P1), (G.sub.P2) and (G.sub.P3): ##STR00050## wherein W in the group G.sub.P is selected from the group consisting of a bond, C(CH.sub.3).sub.2, SO.sub.2 and any combination thereof; each k in the group G.sub.P is independently 0 or an integer from 1 to 4; wherein the molar ratio of sulfone recurring units (R.sub.P0a)/recurring units (R*.sub.P0a) or ketone recurring units (R.sub.P0b)/recurring units (R*.sub.P0b) is at least 1/5 and at most 100/1; and wherein the number of moles of functionalized recurring units (R*.sub.P0a) or (R*.sub.P0b) in the PAE copolymer (P0) used in the reaction mixture is n.sub.1; the number of moles of the vinyl monomer used in the reaction mixture is n.sub.2, and the molar ratio n.sub.2/n.sub.1 is at least 3 and at most 200.

12. The process of claim 11, wherein the vinyl monomer in the reaction mixture includes: at least one sulfobetaine methacrylate of formulae (Mas.sup.1) and/or (Mas.sup.2): ##STR00051## and/or at least one carboxybetaine methacrylate of formulae (Mac.sup.1) and/or (Mac.sup.2): ##STR00052## wherein m in the alkylene chain (CH.sub.2).sub.m is an integer from 1 to 20; and q in the alkylene chain (CH.sub.2).sub.q is an integer from 1 to 20.

13. The process of claim 11, wherein the reacting step is carried out with at least one of the following conditions: in the presence of 2,2-Azobis(2-methylpropionitrile) (AIBN) or 2,2-azobis(2,4-dimethylvaleronitrile (ADVN) as at least one free radical initiator; and/or the solvent S.sub.1 being a polar aprotic solvent selected from the group consisting of 1,3-dimethyl-2-imidazolidinone (DMI), dimethylsulfoxide (DMSO), dimethylsulfone (DMSO2), diphenylsulfone, diethylsulfoxide, diethylsulfone, diisopropylsulfone, tetrahydrothiophene-1,1-dioxide (commonly called tetramethylene sulfone or sulfolane), N-Methyl-2-pyrrolidone (NMP), N-butylpyrrolidinone (NBP), N-ethylpyrrolidone (NEP), N,N-dimethylacetamide (DMAc), N,N-dimethylpropyleneurea (DMPU), dimethylformamide (DMF), tetrahydrothiophene-1-monoxide, and mixtures thereof; and/or at a reaction temperature from 10 C. to 200 C.; and/or in the absence of a crosslinking agent, in the absence of radiation and/or in the absence of radiation initiator.

14. A method for preparing an article comprising the graft polyarylether copolymer (P1) of claim 1, wherein the article is formed from a solution comprising the graft polyarylether copolymer (P1).

15. An article comprising the graft polyarylether copolymer (P1) of claim 1.

16. The article of claim 15, being selected from the group consisting of membranes; fibers; sheets; solution processed films; and solution processed monofilaments.

17. The article of claim 15, being a membrane of a part of a membrane, said membrane being selected from the group consisting of proton exchange membranes, membranes for bioprocessing, hemodialysis membranes, membranes for food and beverage filtration, and membranes for water purification.

18. The graft polyarylether copolymer (P1) of claim 9, wherein m in the alkylene chain (CH.sub.2).sub.m is 2; q in the alkylene chain (CH.sub.2).sub.q is 3; and the number of recurring units Rzw of formulae (Pas.sup.1), (Pas.sup.2), (Pac.sup.1) and/or (Pac.sup.2) in the grafted zwitterionic polymers P.sub.2 is from 10 to 150.

19. The process of claim 11, wherein the number of moles of the vinyl monomer used in the reaction mixture is n.sub.2, and the molar ratio n.sub.2/n.sub.1 is from 10 to 150.

20. The process of claim 12, wherein m in the alkylene chain (CH.sub.2).sub.m is 2; and q in the alkylene chain (CH.sub.2).sub.q is 3.

Description

EXAMPLES

Raw Materials

[0366] K.sub.2CO.sub.3 (potassium carbonate), available from Armand products [0367] daBPA (2,2-diallyl Bisphenol A), available from Sigma-Aldrich [0368] DCDPS (4,4-dichlorodiphenyl sulfone), available from Solvay Specialty Polymers [0369] DHDPS (4,4-dihydroxydiphenyl sulfone or Bisphenol S), available from Konishi chemicals, Japan. [0370] DMAc (dimethylacetamine), available from Sigma-Aldrich [0371] NMP (2-methyl pyrrolidone), available from Sigma-Aldrich [0372] AIBN (azobisisobutyronitrile), available from Sigma-Aldrich [0373] VP (vinyl pyrrolidone), available from Sigma-Aldrich [0374] DMAPS (2-(Methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide), available from Sigma-Aldrich, which is a sulfobetaine methacrylate (SBmA) or formula:

##STR00036##

[0375] Methanol, available from Sigma-Aldrich

Test Methods

GPC Method 1 for Measuring Mn, Mw

[0376] Viscotek GPC Max (Autosampler, pump, and degasser) with a TDA302 triple detector array comprised of RALS (Right Angle Light Scattering), RI (Refractive Index) and Viscosity detectors were used. Samples were prepared as 2 mg/mL in DMAc/LiBr. Samples were run in NMP with 0.2 w/w % LiBr at 65 C. at 1.0 mL/min through a set of 3 columns: a guard column (CLM1019with a 20 k Da exclusion limit), a high Mw column (CLM1013 exclusion of 10 MM Daltons relative to Poly Styrene) and a low Mw column (CLM1011exclusion limit of 20 k Daltons relative to PS). Calibration was done with a single, mono-disperse polystyrene standard of 100 k Da. Light Scattering, RI, and Viscosity detectors were calibrated based on a set of input data supplied with the standards. Samples were prepared as about 2 mg/mL in NMP/LiBr. Viscotek's OMNISec v4.6.1 Software was used for data analysis. The number average molecular weight Mn and weight average molecular weight Mw were reported, and the PDI=Mw/Mn was calculated.

GPC Method 2 for Measuring Mn, Mw (Sulfone Method)

[0377] The molecular weights were measured by gel permeation chromatography (GPC), using methylene chloride as a mobile phase. Two 5p mixed D columns with guard column from Agilent Technologies were used for separation. An ultraviolet detector of 254 nm was used to obtain the chromatogram. A flow rate of 1.5 ml/min and injection volume of 20 L of a 0.2 w/v % solution in mobile phase was selected. Calibration was performed with 10 or 12 narrow molecular weight polystyrene. The number average molecular weight Mn and weight average molecular weight Mw were reported, and the PDI=Mw/Mn was calculated.

Thermal Gravimetric Analysis (TGA)

[0378] TGA experiments were carried out using a TA Instrument TGA Q500. TGA measurements were obtained by heating the sample at a heating rate of 10 C./min from 20 C. to 800 C. under nitrogen.

.SUP.1.H NMR

[0379] .sup.1H NMR spectra were measured using a 400 MHz Bruker spectrometer with TCE as the deuterated solvent. All spectra are reference to residual proton in the solvent.

DSC

[0380] DSC was used to determine glass transition temperatures (Tg) and melting points (Tm)if present. DSC experiments were carried out using a TA Instrument Q100. DSC curves were recorded by heating, cooling, re-heating, and then re-cooling the sample between 25 C. and 320 C. at a heating and cooling rate of 20 C./min. All DSC measurements were taken under a nitrogen purge. The reported Tg values (and if any, Tm values) were provided using the second heat curve unless otherwise noted.

FTIR

[0381] Because of the extensive washing, filtration and drying of the graft copolymer (P1) samples, there should be non-detectable free vinyl monomer (DMAPS in this example) in the dried sample of the graft copolymer (P1). Nonetheless, free residual vinyl monomer can be detected by FTIR using a Bruker Optics Vertex 70 FTIR Bench with MIR source. The spectra were obtained in absorption mode across a diamond ATR crystal. The targeted wavelength range can be selected for the detection of the specific vinyl monomer used in the making of the graft copolymer (P1).

[0382] The procedure for FTIR analysis for the referenced samples was as follows: [0383] a background spectrum was established with fresh 18 megohm water; [0384] a drop of polymer sample was applied to the ATR crystal to ensured its complete coverage; [0385] 32 replicate scans of the spectrum were gathered to produce an average response; [0386] the following correction to each spectrum was applied: [0387] Extended ATR correction for Diamond [0388] Atmospheric correction for water and CO.sub.2 [0389] Baseline correction: Normalize all spectra together based on their Max-min peak values. [0390] ethe normalized spectra were overlaid; and
the peak heights at the targeted wavelength range were visually compared.

I. Preparation of Side Chain Allyl/Vinylene-Functionalized PES Copolymer (P0-A)

[0391] The preparation of the graft PES copolymer (P0-A) is illustrated by Scheme 1.

[0392] To generate the recurring units (R.sub.P0a), 4,4-dichlorodiphenyl sulfone (DCDPS) and 4,4-dihydroxydiphenyl sulfone or Bisphenol S (DHDPS) were used while diallyl bisphenol A (daBPA) and DCDPS were used to generate the various recurring units (R*.sub.P0a). The target mol. % for recurring units (R*.sub.P0a) in the side-chain allyl/vinylene-functionalized PES polymer (P0-A) was 4.5 mol. % to achieve a molar ratio of recurring units (R.sub.P0a)/recurring units (R*.sub.P0a) of 20:1. That is to say, the value n in Scheme 1 for the main recurring unit (R.sub.P0a) should be about 95.5 mol. %, and the combined values: m1+m2+m3 for the three illustrated functionalized recurring units (R*.sub.P0a) should be 4.5 mol. %, said mol. % being based on the total number of moles of recurring units in the PES copolymer (P0-A).

[0393] The polymerization took place in a 20-L glass reactor vessel fitted with an overhead stirrer, a nitrogen inlet and an overhead distillation set-up. The monomers DCDPS (2030.2 g; 7.07 moles), DHDPS (1673.1 g, 6.685 moles) and daBPA (98.6 g; 0.315 mole) were added to the vessel first, followed by the addition of potassium carbonate (977.1 g; 7.07 moles) and NMP (3996.5 g). The reaction mixture was heated from room temperature to 190 C. using a 10 C./min heating ramp. The temperature of the reaction mixture was maintained for around eight hours, depending upon the viscosity of the solution. The reaction was terminated by adding DCDPS (140.7 g) and continuing the reaction for about 30 minutes after which fresh NMP (351.7 g) was added, and then stopping the heat The reaction mixture was filtered and then coagulated into methanol. The polymer was then washed with methanol and water and again with methanol and dried at 110 C.

Characterization of the PES Copolymer (P0-A)

[0394] Sulfone GPC Method 2 (using methylene chloride as mobile phase):

[00001]$\begin{array}{c}{M}_w=71376g/\mathrm{mol},M_n=25407g/\mathrm{mol},\mathrm{PDI}=2.81\\ \mathrm{TGA}:485.7C.\\ \mathrm{DSC}:\mathrm{Tg}=227.7C.\end{array}$

[0395] .sup.1H NMR: The presence of unsaturated groups was confirmed by the appearance of a multiplet at 6.1-6.4 ppm which indicated the incorporation of the 2,2-diallyl bisphenol A monomer in the polymer (P0-A).

[0396] The estimated olefin content measured by .sup.1H NMR was 4.1 mol %. This value provided an actual molar ratio of recurring units (R.sub.P0a)/recurring units (R*.sub.P0a) of 23.4:1. The actual value n in Scheme 1 for the main recurring unit (R.sub.P0a) of PAES copolymer (P0-A) was 95.9 mol. %.

II. Preparation of pDMAPS-Grafted PES Copolymer (P1-A) by Free Radical Reaction

[0397] The preparation of the graft PES copolymer (P1-A) is illustrated by Scheme 2. The actual value n in Scheme 2 for the main sulfone recurring unit (R.sub.P1a) in PAES copolymer (P1-A) was 95.9 mol. %, same as PAES copolymer (P0-A), and the lumped value m for all functionalized recurring units (R*.sub.P0a)which are illustrated in this scheme with a single formula for simplificationshould be 4.1 mol. %, said mol. % being based on the total number of moles of recurring units in the PAES copolymer (P0-A).

[0398] The reaction took place in a 2-L glass reactor vessel fitted with an overhead stirrer and a nitrogen inlet. A sample of the side chain allyl/vinylene-functionalized PES copolymer (P0-A) (200 g containing 0.038 moles of olefinic double bonds) and DMAPS vinyl monomer (107.6 g; 0.38 moles) were added to the reactor and this mixture was dissolved in anhydrous NMP (747 g) and heated to 65 C. The molar ratio of number of moles of DMAPS vinyl monomer to the number of moles of the functionalized recurring units in the PAES copolymer (P0-A) was 69.1. The reaction was purged with nitrogen for 30 minutes and then AIBN (41.2 g) was added in a single portion. The reaction was allowed to continue for 12 hours at 65 C. After 12 hours, the reaction mixture was cooled and about 70-80% of the solvent distilled off under reduced pressure. The copolymer (P1-A) was isolated by coagulating in methanol, and the copolymer (P1-A) was washed repeatedly with hot water until no free poly(2-(Methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide) [pDMAPS] was detected in the water washes via FTIR. The purified copolymer (P1-A) was dried at 100 C. under high vacuum.

Characterization of Graft Polyarylethersulfone Copolymer (P1-A)

GPC Method 1 (RI Detector):

[00002]$\begin{array}{c}\mathrm{Mn}=48979g/\mathrm{mol},\mathrm{Mw}=119902g/\mathrm{mol},\mathrm{PDI}=2.4\\ \mathrm{TGA}:492.3C.\\ \mathrm{DSC}:\mathrm{Tg}=162.9C.\end{array}$

Elemental Analysis:

[00003]$\begin{array}{c}C=57.91\%\\ H=4\%\\ N=1.2\%\\ O=13.77\%\end{array}$

[0399] The estimation of the weight % of pDMAPS was analyzed by the N content which corresponds to 66.9 weight %.

[0400] The PES-g-pDMAPS copolymer (P1-A) was amorphous, as there was no Tm observed via DSC.

II. Preparation of p(DMAPS-VP)-Grafted PES Copolymer (P1-B) by Free Radical Reaction

[0401] The preparation of the graft PES copolymer (P1-B) was carried out according to Scheme 3, a scheme similar to Scheme 2, except that vinyl pyrrolidone (in addition to DMAPS) was further added to the reaction mixture to form grafted p(DMAPS-VP)-grafted PES copolymers.

[0402] The reaction took place in a 2-L glass reactor vessel fitted with an overhead stirrer and a nitrogen inlet. A sample of the side chain allyl/vinylene-functionalized PES copolymer (P0-A) (120 g containing 0.02 moles of olefinic double bonds) and DMAPS vinyl monomer (64.6 g; 0.2312 moles) and vinyl pyrrolidone (25.5 g; 0.23 moles) were added to the reactor and this mixture was dissolved in anhydrous NMP (435 g) and heated to 65 C. The molar ratio of number of moles of vinyl monomers to the number of moles of the functionalized recurring units in the PAES copolymer (P0-A) was 20.1. The reaction was purged with nitrogen for 30 minutes and then AIBN (24.7 g) was added in a single portion. The reaction was allowed to continue for 12 hours at 65 C. After 12 hours, the reaction mixture was cooled and about 70-80% of the solvent distilled off under reduced pressure. The copolymer (P1-B) was isolated by coagulating in methanol, and the copolymer (P1-B) was washed repeatedly with hot water until no free poly(2-(Methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide) [pDMAPS ] was detected in the water washes via FTIR. The purified copolymer (P1-B) was dried at 100 C. under high vacuum.

Characterization of Graft Polyarylethersulfone Copolymer (P1-B)

GPC Method 1 (RI Detector):

[00004]$\begin{array}{c}\mathrm{Mn}=33372g/\mathrm{mol},\mathrm{Mw}=117303g/\mathrm{mol},\mathrm{PDI}=3.52\\ \mathrm{TGA}\left(\mathrm{onset}\right):408C.\end{array}$

Elemental analysis [0403] C59.65% [0404] H4.12% [0405] N1.73% [0406] O16.61%

[0407] The estimation of copolymer of PVP and pDMAPS in the copolymer (P1-B) was analyzed by .sup.1H NMR in deuteriated TCE solvent by integrating the peaks attributed to pDMAPS/VP copolymer attached to the polyarylethersulfone PES and was found to be around 13 mol %.

[0408] The following equation was used for this estimation:

[00005]$\mathrm{mol}\mathrm{pDMAPS}=\frac{\frac{\left(\mathrm{PDMAPS}+\mathrm{PVP}-\mathrm{CH}3\mathrm{PES}\right)}{\#H\mathrm{pDMAPS}+\#H\mathrm{PVP}}}{\left(\frac{\left(\mathrm{PDMAPS}+\mathrm{PVP}-\mathrm{CH}3\mathrm{PES}\right)}{\#H\mathrm{pDMAPS}+\#H\mathrm{PVP}}+\frac{\mathrm{Ar}\mathrm{PES}}{\#H\mathrm{PES}}\right)}$ [0409] in which [0410] PDMAPS, PVP denote the sum of all the hydrogen protons of polyDMAPS and polyvinylpyrrolidone copolymer, respectively; [0411] CH3PES and PES denote the sum of all the hydrogen protons of the isopropylidene groups of PES signals and aromatic protons of the PES polymer respectively; [0412] #H PDMAPS, #H PVP and #H PES denote the number of protons corresponding to the DMAPS monomer, VP monomer and PES polymer, respectively.

[0413] It is to be noted that the exact composition of the copolymer could not be measured since the .sup.1H NMR signals corresponding to vinyl pyrrolidone and DMAPS monomer overlapped each other. Therefore the N content was made up by the contribution of both PVP and pDMAPS.

[0414] Accordingly, the scope of protection is not limited by the description set out above, but is only limited by the claims which follow. Each and every claim is incorporated into the specification as an embodiment of the present invention. Thus, the claims are a further description and are an addition to the preferred embodiments of the present invention.

##STR00037##

##STR00038##

##STR00039##