Polymer Films

Abstract

A polymer film obtainable from curing a composition comprising: (a) a curable ionic compound comprising a bis(sulfonyl)imide group; and (b) a curable non-ionic compound comprising at least 4 vinyl groups.

Claims

1. A polymer film obtainable from curing a composition comprising: (a) a curable ionic compound comprising a bis(sulfonyl)imide group; and (b) a curable non-ionic compound comprising at least 4 vinyl groups.

2. A polymer film according to claim 1 wherein component (b) is a curable non-ionic compound of Formula (I);
RA.sub.nB.sub.mC.sub.qRFormula (I) wherein: A is [CH.sub.2CH?CHCH.sub.2]; B is [CH.sub.2CH(CH?CH.sub.2)]; C is [CH.sub.2CH(C.sub.6H.sub.5)]; n has a value of from 5 to 85% of the sum of (n+m+q); m has a value of from 15 to 95% of the sum of (n+m+q); q has a value of from 0 to 30% of the sum of (n+m+q); and each R independently is H or OH; provided that the non-ionic compound of Formula (I) comprises at least 4 vinyl groups.

3. The polymer film according to claim 1 wherein component (a) is a curable ionic compound of Formula (II): ##STR00015## wherein: each R independently comprises a polymerisable or non-polymerisable group; and M.sup.+ is a cation.

4. The polymer film according to claim 3 wherein each R independently comprises a group selected from vinyl, allyl, alkylenethiol, arylenevinyl, arylenedivinyl, arylene-alkylenethiol, arylene-dialkylenethiol, C.sub.1-6 alkyl and C.sub.6-C.sub.18 aryl, provided that the compound of Formula (II) comprises at least two polymerisable groups.

5. The polymer film according to claim 1 wherein the component (b) has a melting temperature below 50? C.

6. The polymer film according to claim 1 wherein component (b) has a viscosity of less than 600 Poise at 40? C.

7. The polymer film according to claim 1 wherein component (a) is of Formula (III): ##STR00016## wherein: each R independently is a polymerisable or non-polymerisable group; n has a value of 1 or 2; p has a value of 1, 2 or 3; M.sup.+ is a cation; and Z is N or a linking group; provided that the compound of Formula (III) comprises at least two polymerisable groups.

8. The polymer film according to claim 7 wherein n and p both have a value of 1, R is a vinyl group and Z is a phenylene group carrying a vinyl group.

9. The polymer film according to claim 7 wherein p has a value of 2 or 3 and Z is C.sub.1-6-alkylene, C.sub.1-6 perfluoroalkylene, C.sub.6-18-arylene group or a group of the formula N(R).sub.(3-p) wherein each R independently is H or C.sub.1-4-alkyl.

10. The polymer film according to claim 7 wherein p has a value of 1, n has a value of 2 and Z is a C.sub.1-6-alkyl, C.sub.1-6-perfluoroalkyl, C.sub.6-18-aryl group or a group of the formula N(R).sub.2 wherein each R independently is H or C.sub.1-4-alkyl.

11. The polymer film according to claim 1 wherein components (a) and (b) are copolymerisable.

12. The polymer film according to claim 1 wherein the composition comprises 20 to 80 wt % of component (a) and 0.5 to 20 wt % of component (b).

13. The polymer film according to claim 1 wherein the composition optionally further comprises one or more of the following components: (c) a compound comprising one and only one polymerisable group; (d) one or more radical initiators; and (e) solvent.

14. A composition comprising: (a) a curable ionic compound comprising a bis(sulfonyl)imide group; (b) a curable non-ionic compound comprising at least 4 vinyl groups; optionally (c) a compound comprising one and only one polymerisable group; optionally (d) one or more radical initiators; and optionally (e) solvent.

15. A process for preparing a polymer film comprising the steps of: (i) providing a porous support; (ii) impregnating the porous support with a composition according to claim 14; and (iii) curing the composition.

16. The process according to claim 15 wherein the curing comprises a first curing step and a second curing step.

17. The process according to claim 16 wherein the first and second curing steps are respectively selected from (i) UV curing then thermal curing; (ii) UV curing then electron beam curing; and (iii) electron beam curing then thermal curing.

18. The process according to claim 16 which comprises curing the composition in the first curing step to form a polymer film, winding the polymer film onto a core, optionally together with an inert polymer foil, and then performing the second curing step.

19. A cation exchange membrane comprising the polymer film according to claim 1.

20. A bipolar membrane comprising the polymer film according to claim 1.

21. A method of using the cation exchange membrane according to claim 19 for the treatment of polar liquids, for the production of acids and bases or for the generation of electricity.

22. The polymer film according to claim 1 wherein the component (b) has a molecular weight of at least 600 g/mol and a number average molecular weight (Mn) not higher than 15,000 Da.

23. The polymer film according to claim 1 wherein the component (b) has a melting temperature below 50? C., a viscosity of less than 600 Poise at 40? C., and a number average molecular weight (Mn) not higher than 15,000 Da.

24. The polymer film according to claim 2 wherein the component (b) has a melting temperature below 50? C., a viscosity of less than 600 Poise at 40? C., and a number average molecular weight (Mn) not higher than 15,000 Da.

25. The polymer film according to claim 3 wherein the component (a) comprises at least two polymerisable groups comprising ethylenically unsaturated groups, preferably vinyl groups, or thiol groups.

26. The polymer film according to claim 25 wherein the component (b) has a melting temperature below 50? C., a viscosity of less than 600 Poise at 40? C., and a number average molecular weight (Mn) not higher than 15,000 Da.

27. A method of using the bipolar membrane according to claim 20 for the treatment of polar liquids, for the production of acids and bases or for the generation of electricity.

28. The polymer film according to claim 3 wherein the component (a) comprises vinyl groups, or thiol groups.

Description

EXAMPLES

[0163] In the following non-limiting examples all parts and amounts are by weight unless specified otherwise.

[0164] XL-B and MM-P are synthesized in the laboratory according the procedures below.

Synthesis of MM-P and XL-B CI-SS

[0165] ##STR00011##

[0166] Thionyl chloride (109 mL, 178.46 g, 1.5 mol, 3 moleq) was added dropwise to a solution of 4-vinylbenzenesulfonic acid lithium salt (95.08 g, 0.500 mol, 1 moleq) and 4OH-TEMPO (50 mg, 500 ppm) in DMF (300 mL) in a double-walled reactor that was actively cooled to 5? C. After the addition was completed, the solution was allowed to slowly heat to room temperature and was stirred for another 16 hours. Then the reaction mixture was poured into 1 litre of cold 1M KCI in a separation funnel. The bottom layer was removed and dissolved in 500 mL diethylether. This solution was washed with a 1M KCI-solution (300 mL). The organic layer was dried over sodium sulfate, filtered and concentrated in vacuum to give a yellow oil. The crude product was used without further purification in the next step. Typical yield is 89.5 g (88%). HPLC-MS purity>98%; .sup.1H-NMR: <2 wt % DMF, 0% diethyl ether.

NH2-SS

[0167] ##STR00012##

[0168] Thionyl chloride (109 mL, 178.46 g, 1.5 mol, 3 moleq) was added dropwise to a solution of 4-vinylbenzene sulfonic acid lithium salt (95.08 g, 0.500 mol, 1 moleq) and 4OH-TEMPO (50 mg, 500 ppm) in DMF (300 mL) in a double-walled reactor that was actively cooled to 5? C. After the addition was completed, the solution was allowed to slowly heat to room temperature and was stirred for another 16 hours. Then the reaction mixture was poured into 1 litre of cold 1M KCI in a separation funnel. The bottom layer was removed and was added dropwise to a solution of ammonium hydroxide 25% in water (250 ml, 3.67 mol, 15 moleq) and 4OH-TEMPO (50 mg, 500 ppm) in a double-walled reactor that was actively cooled to 5? C. After the addition was completed, the solution was stirred for 1 hour. The solution was then allowed to heat to room temperature and was stirred for one hour. Then the reaction mixture was cooled back to 5? C. and the product was filtered off and washed with 50 mL of cold water. The product was dried overnight in vacuum at 30? C. and used without further purification. Typical yield was 66.8 g (73%). HPLC-MS purity>95%.

Preparation of XL-B

[0169] ##STR00013##

[0170] Before the synthesis, vinyl benzene sulphonamide was dried in a vacuum oven overnight (30? C., vac). To a solution of the dried vinyl benzene sulphonamide (11.12 g, 0.061 mol, 1 moleq) and 4OH-TEMPO (30 mg, 500 ppm) in THF (100 mL) was added LiH (1.06 g, 0.134 mol, 2.2 moleq) as a solid at once. The reaction mixture was stirred for 30 minutes at room temperature. Then, a solution of CI-SS (12.3 g, 0.061 mol, 1 moleq) in THF (50 mL) was added to the reaction mixture. After addition, the reaction mixture was heated to 60? C. (water bath temperature). After two days, the reaction mixture was filtrated over celite to remove the excess of LiH. Celite was added and the resulting slurry was stirred for 5 minutes. Then, the celite was filtered off and washed with 100 mL ethyl acetate. The solvent was then evaporated in vacuo and the resulting white foam was washed with 500 mL diethyl ether overnight. The resulting white powder was filtered off and dried in a vacuum oven at 30? C. for 16 h yielding a white solid. Typical yield is 11 g (51%). HPLC-MS purity>94%; .sup.1H-NMR : <1 wt % residual solvents, <5 wt % styrene sulphonate or styrene sulphonamide; ICP-OES: 18-22 g Li/kg product.

Preparation of MM-P

[0171] ##STR00014##

[0172] Before the synthesis, benzenesulphonamide was dried in a vacuum oven overnight at 30? C. To a solution of the dried benzenesulphonamide (0.100 mol, 1 moleq) and 4OH-TEMPO (30 mg, 500 ppm) in THF (100 mL) was added LiH (0.300 mol, 3 moleq) as a solid at once. The reaction mixture was stirred for 30 minutes at room temperature. Then, a solution of vinyl benzene sulphonyl chloride (CI-SS, 0.100 mol, 1 moleq) in THF (50 mL) was added and the reaction mixture was heated to 60? C. (water bath temperature) for 16 h. The resulting solution was filtrated over celite and the resulting foam was dissolved in 500 mL ethyl acetate. Celite was added and the resulting slurry was stirred for 5 minutes. Then, the celite was filtered off and washed with 100 mL ethyl acetate. The solvent was then evaporated in vacuum and the resulting white foam was crushed with 500 mL diethyl ether overnight. The resultant compound MM-P was collected by filtration and isolated as a white hygroscopic powder. Yield was 79%, purity>96%, residual solvents<1%, residual LiSS<2% and Li content between 23-28 mg/kg.

TABLE-US-00002 TABLE 1 Ingredients used in the Examples: Component Abbreviation Type Description/supplier XL-B (a) Benzenesulfonamide, 4-ethenyl-N-[(4- ethenylphenyl)sulfonyl]-, lithium salt LiSS Styrene sulfonate, lithium salt from Tosoh chemicals Cl-SS Styrene sulfonate, chloride NH2-SS Styrene sulfonamide Benzene From Sigma-Aldrich suphonamide PBD-SA (b) Polybutadiene, predominantly 1,2-adition from Sigma- Aldrich Ricon? 100 (b) Polybutadiene from Cray Valley Ricon? 152 (b) Polybutadiene from Cray Valley Ricon? 130 CF (b) Polybutadiene from Cray Valley Ricon? 131 (b) Polybutadiene from Cray Valley Ricon? 156 (b) Polybutadiene from Cray Valley B-1000 (b) Polybutadiene from Nippon Soda Co. B-2000 (b) Polybutadiene from Nippon Soda Co Poly BD (b) Polybutadiene from Cray Valley R45HTLO Krasol? LBH (b) Polybutadiene from Cray Valley P3000 CF Krasol? LBH- (b) Polybutadiene from Cray Valley P2000 CF MM-P (c) Benzenesulfonamide, 4-ethenyl-N-(phenylsulfonyl)-, lithium salt MeOH (e) Methanol, from Sigma-Aldrich IPA Isopropanol from Sigma-Aldrich THF Tetrahydrofuran from Sigma-Aldrich DMF Dimethylformamide from Sigma-Aldrich DCM Dichloromethane from Sigma-Aldrich MCH Methylcyclohexane from Sigma-Aldrich NMP N-methylpyrrole from Sigma-Aldrich DMSO Dimethylsulfoxide from Sigma-Aldrich 1-methoxy-2- (e) From Sigma-Aldrich propanol PW (e) Purified water TFA Trifluoroacetic acid from Sigma-Aldrich KCl Potassium chloride from Sigma-Aldrich LiH Lithium hydride from Sigma-Aldrich Celite Celite S, diatomaceous earth (SiO.sub.2) from Sigma- Aldrich 4OH-TEMPO 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl, from Evonik LAP (d) phenyl-2,4,6-trimethylbenzoylphosphinate, lithium salt from Ambeed TPO-L (d) (ethyl(2,4,6-trimethylbenzoyl)-phenyl phosphinate from IGM resin V-59 (d) 2,2-Azobis(2-methylbutyronitrile) from Fujifilm-Wako Chemicals Non-woven support PP/PE 26 gsm and 80 ?m thick

Preparation of the Examples

[0173] Polymer films (cation exchange membranes) according to the first aspect of the present invention and the Comparative Example were prepared by applying each of the compositions described in Table 2 onto a nonwoven porous support made from PP/PE coextruded fibers with a weight of 26 gram per square meter and a thickness of 80 ?m using a 4 ?m Meyer bar and then curing the composition by UV curing by placing the samples on a conveyor at 5 m/min equipped with a D-bulb in a Light Hammer? 10 of Fusion UV Systems Inc. at 40% intensity followed by thermal curing at 90? C. for 3 hours as second curing step. The thermal curing was performed with a foil laminated on top of the coating to avoid evaporation of the solvents and exposure to oxygen. This formed a polymer film (including the porous support) of thickness 80 ?m.

[0174] The PS and ER of the resultant polymer films were measured as described below and the results are shown in Table 2 below.

TABLE-US-00003 TABLE 2 Curable compositions and results of prepared CEMs Ingredients (wt %) Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Ex. 7 Ex. 8 PW 18.7 18.7 18.7 18.7 18.7 18.7 18.7 18.7 1-methoxy-2- 5.3 5.3 5.3 5.3 5.3 5.3 5.3 5.3 propanol Ricon 100 12.5 Ricon 152 12.5 Ricon 130 CF 12.5 Ricon 131 12.5 Ricon 156 12.5 B-1000 12.5 B-2000 12.5 Poly BD R45HTLO 12.5 4OH-TEMPO 1 1 1 1 1 1 1 1 (2% in Water) V-59 1 1 1 1 1 1 1 1 TPO-L 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 LAP 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 XL-B 60.8 60.8 60.8 60.8 60.8 60.8 60.8 60.8 TOTAL (wt %) 100 100 100 100 100 100 100 100 PS 0.05-0.5M 70.1 76.2 86.4 82 81.9 83.8 70.0 70.6 NaOH (%) ER 0.5M NaCl 2.5 2.3 3.3 3.0 2.4 2.8 1.9 2.8 (ohm .Math. cm.sup.2) Ingredients (wt %) Ex. 9 Ex.10 Ex. 11 Ex. 12 Ex. 13 CEx. 1 PW 18.7 18.7 17.2 17.2 17.2 21.4 1-methoxy-2-propanol 5.3 5.3 6.1 MeOH 8 5.4 0.2 Krasol LBH P3000 CF 12.5 Krasol LBH-P2000 CF 12.5 PBD-SA, predominantly 2.6 5.2 10.4 1,2-addtion 4OH-TEMPO (2% in Water) 1 1 1 1 1 1 V-59 1 1 1 1 1 1 TPO-L 0.5 0.5 0.5 0.5 0.5 0.5 LAP 0.5 0.5 0.5 0.5 0.5 0.5 MM-P 12.9 12.9 12.9 XL-B 60.8 60.8 56.3 56.3 56.3 69.5 TOTAL 100 100 100 100 100 100 PS 0.05-0.5M NaOH 77.6 89.0 79.7 73.0 70.2 56.4 (%) ER 0.5M NaCl 2.1 4.4 2.0 1.5 1.6 1.8 (ohm .Math. cm.sup.2)

Methods

Measurement of Electrical Resistance (ER)

[0175] ER (ohm.cm.sup.2) of the polymer films prepared in the Examples was measured by the method described by Dlugolecki et al., J. of Membrane Science, 319 (2008) on page 217-218 with the following modifications: [0176] the auxiliary polymer films were CMX and AMX from Tokuyama Soda, Japan; [0177] the capillaries as well as the Ag/AgCl references electrodes (Metrohm type 6.0750.100) contained 3M KCI; [0178] the calibration liquid and the liquid in compartment 2, 3, 4 and 5 was 0.5 M NaCl solution at 25? C.; [0179] the effective polymer film area was 9.62 cm.sup.2; [0180] the distance between the capillaries was 5.0 mm; [0181] the measuring temperature was 25? C.; [0182] a Cole Parmer Masterflex console drive (77521-47) with easy load II model 77200-62 gear pumps was used for all compartments; [0183] the flowrate of each stream was 475 ml/min controlled by Porter Instrument flowmeters (type 150AV-B250-4RVS) and Cole Parmer flowmeters (type G-30217-90); and [0184] the samples were equilibrated for at least 1 hour at room temperature in a 0.5 M solution of NaCl prior to measurement.

Measurement of Permselectivity (PS)

[0185] The permselectivity PS (%) that is the selectivity to the passage of ions of opposite charge to that of the polymer films prepared in the examples, was measured as follows. The polymer film to be analyzed was placed in a two-compartment system. One compartment is filled with a 0.05M solution of NaOH and the other with a 0.5M solution of NaOH.

Settings

the capillaries as well as the Ag/AgCl reference electrodes (Metrohm type 6.0750.100) contained 3M KCI;

[0186] the effective polymer film area was 9.62 cm.sup.2; [0187] the distance between the capillaries was ca 15 mm; [0188] the measuring temperature was 21.0?0.2? C.; [0189] a Cole Parmer Masterflex console drive (77521-47) with easy load II model 77200-62 gear pumps was used for the two compartments; [0190] Porter Instrument flowmeters (type 150AV-B250-4RVS) and Cole Parmer flowmeters (type G-30217-90) were used to control the flow constant at 500 ml/min; [0191] The samples were equilibrated for 1 hr in a 0.5 M NaOH solution prior to measurement. The voltage was read from a regular VOM (multitester) after 20 minutes.

[0192] Preferably the PS for NaOH is at least 70%.