WO2010069277A2

WO2010069277A2 - Polymeric aliphatic ion-exchange materials and their applications

Info

Publication number: WO2010069277A2
Application number: PCT/CZ2009/000150
Authority: WO
Inventors: Jan Zitka; Jan Schauer; Miroslav Bleha
Original assignee: Institute Of Macromolecular Chemistry As Cr, V.V.I.
Priority date: 2008-12-15
Filing date: 2009-12-10
Publication date: 2010-06-24
Also published as: CZ2008809A3; CZ303585B6; WO2010069277A3

Abstract

The invention concerns polymer ion-exchange materials based on copolymers o phosphonic acids (I) and diphosphonic acids (II) with an unsaturated polymerizable C=C bond and monomers with one or more polymerizable C=C bonds selected from the group of vinyl halides, vinylidene halides, vinyl esters, vinyllactames, acrylic and methacrylic acids, their halogen derivatives, esters, amides and nitriles of acrylic and methacrylic acids and their halogen derivatives. The materials according to the present invention are designed for preparation of homogenous and heterogenous membrane fuel cells and other devices and processes utilizing ion-exchange materials.

Description

Polymeric aliphatic ion-exchange materials and their applications

Technical field

The invention concerns aliphatic polymeric ion-exchange materials and their applications

Background art

At present ion-exchange membranes find numerous applications both on laboratory and industrial scale. Electrochemical desalting of seawater and brackish waters, separation of electrolytes from nonelectrolytes, purification of pharmaceutical preparations, solid electrolytes and other processes rank among most significant applications. Ion-exchange membranes are produced as homogenous membranes, which are single-phase ion- exchange systems and as heterogenous membranes which consist of dispersions of ion- exchange particles in a hydrophobic polymer binder (J. Membr. Sci. 250 (2005) 151). Most of the present cation-exchange membranes are prepared from polymers bearing sulfonic, phosphonic, and carboxylic acid groups or other acid groups in side-chains which can dissociate in water (J. Membr. Sci. 259, (2005) 10). The membranes in the hydrated state are ion-conductive on dissociation of the acid functional group. At present, perfluorinated homogenous membranes are most frequently used as polymer electrolytes in membranes of fuel cells operating below the boiling point of water (U.S. Pat. No. 6 692 569). They are characterized by high ion-conductivity, suitable water absorption capacity, good mechanical properties and extraordinary resistance to oxidation in fuel cells. The oxidation leads to embrittlement of the membrane electrolyte, possible rupture of the membrane as well as to lower fuel-cell performance (J. Membr. Sci. 243, (2004) 327). As an alternative to the perfluorinated materials, partly fluorinated and nonfluorinated ion-exchange materials are developed and used (U.S. Pat. No. 5 422 411). The most important of them are sulfonated aromatic polymers based on poly(ether ketone)s (DE 4219077), sulfonated poly(sulfone)s (J. Membr. Sci. 83, (1993), 211), sulfonated poly(phenylene sulfide)s (DE Pat. 19527435). These materials are frequently characterized by a very low resistance to oxidation (oxidation stability) in service in fuel cell and a high permeability to methanol when used in direct methanol fuel cells (Chem. Mater. 8, (1996) 610). An advantage of polymeric ion-exchange and ion-conductive materials based on copolymers of aliphatic phosphonic and diphosphonic acids and their derivatives containing polymerizable C=C bonds according to the invention over sulfonated aromatic polymers is their enhanced stability to oxidation, their good mechanical properties and excellent stability to thermal degradation. A drawback of low- temperature fuel cells (operating below the boiling temperature of water) is that the membrane dries up near the boiling point of water and loses ion conductivity. Polymeric membrane fuel cells operating above the boiling point of water, at 100 °C - 200 ⁰C (medium-temperature fuel cells), use as electrolytes basic polymers doped with mineral acids. These are mainly polybenzimidazole and its derivatives doped with phosphoric acid, which are ion-conductive at temperatures above 100 °C . (Patent WO 096/13872). An advantage of medium-temperature fuel cells is their higher tolerance to possible catalytic poisons in fuel (J. Appl. Electrochem. 31, (2001) 773), especially to carbon monoxide, a gain of high-potential heat and a higher cell performance. They do not need moisturing of the fuel and oxidant. However, their drawback is the washing out of phosphoric acid from the membrane with water formed by chemical reaction in the fuel cell, mainly at the start and switching off the fuel cell. To enhance the ion conductivity, ion-conductive fillers are usually added. These are, e.g., sulfates, phosphates, zeolites and heteropolyacids (J. Membr. Sci. 226, (2003) 169). The present scientific and technical findings report on preparation of ion-exchange polymer materials based on a vinyl- containing phosphonic acid by mixing a polymer with a vinyl-containing phosphonic acid, preparation of a two-dimensional structure (membrane) on a carrier and subsequent polymerization of the vinyl-containing phosphonic acid (US Patent 2005147859) or plasma-polymerized vinylphosphonic acid on PTFE carrier, when a graft copolymer is obtained (Chem. Eng. Commun. 190, (2003) 1085). The thus obtained materials are macro- or microheterogenous. They are polymer networks or graft copolymers. The present scientific and technical findings report also on preparation of ion-exchange polymer materials based on a vinyl-containing phosphonic acid by mixing a poly(vinylphosphonic acid) with nitrogen heterocyclic compounds such as imidazole (Polymer 45, (2005) 2986). However, the system is water-soluble and hence unsuitable for low-temperature fuel cells. In copolymerization of a vinyl-containing phosphonic acid with water-soluble monomers, a water-soluble copolymer is obtained (Solid State Ionics 164, (2003) 169). A drawback of the solution is the solubility of the system in water and hence the solution is unsuitable for low-temperature fuel cells. The water-soluble ion-exchange polymer is suitable for preparation of solid electrolyte as a membrane after crosslinking. The present scientific and technical findings also report on preparation of statistical copolymers of vinylphosphonic acid esters with styrene, which, however, possess poor mechanical properties, showing, after hydrolysis, almost no ion-conductivity (J. Appl. Polym. Sci. 74 (1999) 83). The present scientific and technical findings do not report on preparation of ion-conductive polymers based on non-grafted statistical copolymers or mixtures of polymers of which at least one polymer bears phosphonic acid groups as substituents on the main chain or in a side-chain which would be soluble without using a multifunctional comonomer, film-forming from polymer solution, highly ion-conductive, which have good mechanical properties and high oxidation stability to radicals and which would be exploitable in applications for ion-exchange materials, first of all as electrolytes in fuel cells.

Summary of the invention

The subject of the present invention is aliphatic polymeric ion-exchange materials based on copolymers of phosphonic or diphosphonic acids and their derivatives containing a polymerizable C=C bond, which are ion-conductive either directly or after chemical modification, which usually includes re-esterifϊcation and subsequent hydrolysis or direct hydrolysis of an ester or amide of phosphonic or diphosphonic acid. The materials according to the present invention are designed for preparation of homogenous and heterogenous membranes and for applications in membrane fuel cells and other processes utilizing ion-exchange materials. Their substance consists in that they contain polymers bearing phosphonic acid groups as substituents on the main chain or in side-chains. Preparation of the materials according to the present invention consists of solution, emulsion, suspension or block polymerization of phosphonic acid (I) or diphosphonic acid (II) or their derivatives containing polymerizable bonds of the type C=C

R₁ R₃ R₆ PO₃R₄R₅ I I I I

C=C C=C R₂ PO₃R₄R₅ R₇ PO₃R₄R₅ (I) (II)

where Ri is a substituent from the group (H, F, Cl, Br), R₂ is a substituent from the group (H, F,), R₃ is a substituent from the group (H, F, Cl, Br, I, COOR₈, COCl, CON R₈Rg), R₄ is a substituent from the group (H, substituted alkyl, unsubstituted alkyl, substituted aryl, unsubstituted aryl), R₅ is a substituent from the group (H, substituted alkyl, unsubstituted alkyl, substituted aryl, unsubstituted aryl), 100 R₆ is a substituent from the group (H, F),

101 R₇ is a substituent from the group (H, F),

102 Rg is a substituent from the group (H, substituted alkyl, unsubstituted alkyl, substituted

103 aryl, unsubstituted aryl)

104 with another comonomer containing polymerizable C=C bond. For preparation of a

105 material according to the present invention, any of their inorganic or organic salt or

106 possibly chlorides and fluorides of the acids can be used as derivatives of phosphonic

107 acid (I) or diphosphonic acid (II) containing polymerizable bonds of the type C=C. As

108 comonomers, acrylates, methacrylates, branched vinyl esters, acrylonitrile,

109 methacrylonitrile, vinyl halides, vinylidene halides can be used without restriction to this

110 group of comonomers. Of advantage is in particular the use of acrylonitrile and

111 methacrylonitrile. When using monomers containing more polymerizable unsaturated

112 bonds in the reaction mixture in the range 0.1 mol. - 10 mol. % and higher, branched or

113 crosslinked, usually insoluble products are obtained. Due to insolubility, such systems

114 must be polymerized already in the form of the final polymer. The polymerization can be

115 carried out in the form of a thin film, when the material is prepared and processed in the

116 form of membrane in a single step. As polymerization initiators, radical initiators, UV

117 radiation, photoinitiators, electron beam, electrochemical initiation and other common

118 methods of initiation of radical polymerization can be used. Polar solvents such as

119 dimethyl sulfoxide (DMSO), dimethylformamide (DMF), dimethylacetamide (DMAc),

120 iV-methylpyrrolidone (NMP), Λf-methylimidazole (NMI), phosphoric acid (H₃PO₄) and

121 other solvents can be used, in which the final polymer dissolves. The use of nontoxic

122 DMSO and H₃PO₄ is especially advantageous. The solvent - precipitant mixtures in the

123 ratio when the final polymer is soluble can be also used. The use of a polar solvent -

124 water with the water content up to 10 % is of advantage. The water content 3 - 7 % is

125 especially advantageous as such mixtures dissolve some salts of phosphonic and

126 diphosphonic acids. For precipitation polymerizations, polar-substituted hydrocarbons

127 such as lower aliphatic alcohols or ketones and other solvents in which the final polymer

128 does not dissolve can be used. Especially advantageous is also the use of water-

129 acrylonitrile in the ratio higher than 15:1, in which the latter is soluble. Isolation of a

130 polymer from solution can be carriod out by evaporation of solvent or precipitation of a

131 polymer into a precipitant in the case of solution polymerization. In the case of

132 precipitation polymerization, the polymer is obtained by filtration or evaporation of the

133 solvent (precipitant). The method of preparation of polymeric membranes consists in

134 dissolution of the polymer according to the invention, bearing phosphonic groups as

4 SUBSTITUTE SHEET (RULE^~26) 135 substituents in the main chain or side-chain, pouring the solution onto an inert sheet,

136 evaporation of the solvent and peeling off the membrane from the sheet. Another method

137 of preparation of polymeric membranes consists in dissolution of a homopolymer or

138 copolymer bearing phosphonic groups prepared according to the invention in a solvent

139 suitable for the polymer and in mixing with an ion-nonconductive polymer dissolved in

140 the same solvent in which the ion-conductive solvent is soluble, mixing the solutions and

141 casting the resulting solution as a film onto an inert sheet, evaporation of the solvent and

142 peeling off the resulting membrane from the sheet. Another method of preparation of

143 polymeric membranes consists in dispersing milled ion-conductive particles of the size 1

144 - 100 μm, to advantage 20 - 80 μm, in an ion-nonconductive polymer above its melting

145 temperature and subsequent pressing, injection, calendering or another common

146 technology of polymer processing. It is advantageous to keep the content of ion-

147 conductive particles in the membrane in the range 40 wt. % - 75 wt. %. The material

148 according to the invention can be processed using other common polymer processing

149 technologies. The material processing is not limited to membrane processing. Another

150 potential example is the processing into spherical micrometer-to-millimeter particles for

151 application as ion-exchange resins. Specification of examples of preparation and

152 processing of materials according to the invention follows without being limited to them. 153

154 Examples of realization of the invention 155

156 Example 1

157 A polymerization mixture consisting of 12.04 g of vinylphosphonic acid of purity 84.9 %

158 (0.095 mol), 18.07 g (0.34 mol) of acrylonitrile, 0.2015 g of, the initiator 2,2'-azobis(2-

159 methylpropanenitrile) and 70.00 g dimethyl sulfoxide (DMSO) was prepared. The

160 mixture was freed of oxygen by bubbling with an inert gas for 10 min, air-tightly closed

161 and polymerized at 70 °C for 5 h. Then the mixture was diluted with 50 g DMSO and the

162 polymer was precipitated under stirring into 2 1 of ethanol. The polymer was filtered off

163 and washed with 4 x 0.5 1 of ethanol for 4 x 30 min under constant stirring. The polymer

164 was dried at 25 °C under atmospheric pressure to constant weight. For elemental analysis

165 a membrane was prepared from a DMF solution, which was dried under atmospheric

166 pressure at 70 °C and finally dried under atmospheric pressure at 160 ⁰C for 30 min. The

167 results of elemental analysis of the polymer in the H⁺ form were: C 55.53 wt. %, H 6.10

168 wt. %, N 18.61 wt. %, P 5.04 wt. %. The ion-exchange capacity of the polymer was 3.25

169 meq/g according to the phosphorus content. 170

171 Example 2

172 A polymerization mixture consisting of 15.00 g (0.064 mol) bis(2-chloroethyl)

173 vinylphosphonate, 15.00 g (0.15 mol) methyl methacrylate, 0.1078 g of the initiator 2,2'-

174 azobis(2-methylpropanenitrile) and 60.00 g of dimethylformamide (DMF) was prepared.

175 The mixture was freed of oxygen by bubbling with an inert gas for 10 min, air-tightly

176 closed and polymerized at 70 °C for 13 h. The polymer was precipitated into 2 1 of

177 demineralized water. The polymer was filtered off and washed with 4 x 0,5 1 of

178 demineralized water for 4 x 30 min under constant stirring. The polymer was dried at 25

179 °C under atmospheric pressure to constant weight. For elemental analysis, a membrane

180 was prepared from a DMF solution, which was dried under atmospheric pressure at 70

181 °C and finally dried under atmospheric pressure at 160 °C for 30 min. The results of

182 elemental analysis of the polymer were: C 51.45 hmot. %, H 6.10 wt. %, P 3.82 wt. %,

183 Cl 7.79 wt. %. 184

185 Example 3

186 A polymerization mixture consisting of 3.08 g of vinylphosphonic acid of purity 84.9 %

187 (0.024 mol), 3.05 g (0.030 mol) of methyl methacrylate, 0.0507 g of the initiator 2,2'-

188 azobis(2-methylpropanenitrile and 100.00 g of 85% phosphoric acid of purity p.a. was

189 prepared. The mixture was freed of oxygen by bubbling with an inert gas for 10 min, air-

190 tightly closed and polymerized at 80 ⁰C for 16 h. The polymer was precipitated into 2 1

191 of demineralized water. The polymer was filtered off and washed with 4 x 0.5 1 of

192 demineralized water for 4 x 30 min under constant stirring. The polymer was dried at 25

193 °C under atmospheric pressure to constant weight. For elemental analysis, a membrane

194 was prepared from a DMF solution, which was dried under atmospheric pressure at 70

195 °C and finally dried under atmospheric pressure at 160 ⁰C for 30 min. The results of

196 elemental analysis of the polymer in the H⁺ form were: C 58.28 wt. %, H 7.94 wt. %, P

197 0.78 wt. %. %. The ion-exchange capacity of the polymer was 0.50 meq/g according to

198 the phosphorus content. 199

200 Example 4

201 A polymerization mixture consisting of 4.10 g (0.015 mol) of tetrasodium (ethen-1,1-

202 diyl)bisphosphonate, 6.00 g (0.11 mol) of acrylonitrile, 0.2068 g of the initiator 2,2'-

203 azobis(2-methylpropanenitrile) and 30.00 g of 85% phosphoric acid was prepared. The

204 mixture was freed of oxygen by bubbling with an inert gas for 10 min, air-tightly closed 205 and polymerized at 70 °C for 3 h. The polymer was precipitated into 2 1 of demineralized

206 water. The polymer was filtered off and washed with 4 x 0.5 1 of demineralized water for

207 4 x 30 min under constant stirring. The polymer was dried at 25 ⁰C under atmospheric

208 pressure to constant weight. For elemental analysis, a membrane was prepared from a

209 DMF solution, which was dried under atmospheric pressure at 70 °C and finally dried

210 under atmospheric pressure at 160 °C for 30 min. The results of elemental analysis of the

211 polymer in the H⁺ form were: C 59.64 wt. %, H 5.65 wt. %, N 21.49 wt. %, P 3.31 wt. %.

212 The ion-exchange capacity of the polymer is 2.13 meq/g according to the phosphorus

213 content. 214

215 Example 5

216 A polymerization mixture consisting of 9.04 g of vinylphosphonic acid of purity 84.09 %

217 (0.071 mol), 6.01 g (0.090 mol) of methacrylonitrile, 0.2041 g of the initiator 2,2'-

218 azobis(2-methylpropanenitrile) and 30.00 g dimethylformamide (DMF) was prepared.

219 The mixture was freed of oxygen by bubbling with an inert gas for 10 min, air-tightly

220 closed and polymerized at 70 °C for 6 h. Then the mixture was precipitated under stirring

221 into 2 1 of a mixture butan-1-ol/diethyl ether (1:1). The polymer was filtered off and

222 washed with 4 x 0.25 1 of a mixture butan-1-ol/diethyl ether (1:1) for 4 x 30 min under

223 constant stirring. The polymer was dried at 25 °C under atmospheric pressure to constant

224 weight. For elemental analysis a membrane was prepared from a DMF solution, which

225 was dried under atmospheric pressure at 70 °C and finally dried under atmospheric

226 pressure at 160 °C for 30 min. The results of elemental analysis of the polymer in the H⁺

227 form were: C 59.19 wt. %, H 7.25 wt. %, N 15.75 wt. %, P 6.19 wt. %. The ion-

228 exchange capacity of the polymer was 4.00 meq/g according to the phosphorus content. 229

230 Example 6

231 A polymerization mixture consisting of 10.23 g (0.080 mol) of vinylphosphonic acid of

232 purity 84.9 %, 10.02 g (0.10 mol) of vinylidene chloride, 0.2022 g of the initiator 2,2'-

233 azobis(2-methylpropanenitrile) and 20.00 g of dimethylformamide (DMF) was prepared.

234 The mixture was freed of oxygen by bubbling with an inert gas for 10 min, air-tightly

235 closed and polymerized at 70 ⁰C for 4 h. Then the mixture was precipitated under stirring

236 into 2 1 of water. The polymer was filtered off and washed with 4 x 0.5 1 of water for 4 x

237 30 min under constant stirring. The polymer was dried at 25 ⁰C under atmospheric

238 pressure to constant weight. For elemental analysis, a membrane was prepared from a

239 DMF solution, which was dried under atmospheric pressure at 70 °C. The results of 240 elemental analysis of the polymer in the H⁺ form were: C 26.97 vvt. %, H 2.84 wt. %, Cl

241 53.49 wt. %, P 5.82 wt. %. The ion-exchange capacity of the polymer was 3.75 meq/g

242 according to the phosphorus content. 243

244 Example 7

245 A polymerization mixture consisting of 7.50 g of vinylphosphonic acid of purity 84.9 %

246 (0.059 mol), 7.55 g (0.038 mol) of a mixture of branched vinyl alkanoates ClO, 0.2006 g

247 of the initiator 2,2'-azobis(2-methylpropanenitrile) and 30.00 g dimethylformamide

248 (DMF) was prepared. The mixture was freed of oxygen by bubbling with an inert gas for

249 10 min, air-tightly closed and polymerized at 70 °C for 4 h. Then the mixture was

250 precipitated under stirring into 2 1 of a mixture acetonitrile-diethyl ether 9:1. The

251 polymer was filtered off and washed with 4 x 0.25 1 of a mixture acetonitrile-diethyl

252 ether 9:1 for 4 x 30 min under constant stirring. The polymer was dried at 25 °C under

253 atmospheric pressure to constant weight. For elemental analysis, a membrane was

254 prepared from a DMF solution, which was dried under atmospheric pressure at 70 ⁰C and

255 finally dried under atmospheric pressure at 160 °C for 10 min. The results of elemental

256 analysis of the polymer in the H⁺ form were: C 41.11 wt. %, H 4.66 wt. %, N 10.71 wt.

257 %, P 6.19 wt. %. The ion-exchange capacity of the polymer 4.00 meq/g according to the

258 phosphorus content. 259

260 Example 8

261 A polymerization mixture consisting of 5.02 g (0.039 mol) of vinylphosphonic acid of

262 purity 84.9 %, 5.03 g (0.094 mol) of acrylonitrile, 0.0100 g of the initiator 2,2'-azobis(2-

263 methylpropanenitrile) and 50,00 g of ethanol was prepared. The mixture was freed of

264 oxygen by bubbling with an inert gas for 10 min, air-tightly closed and polymerized at 70

265 °C for 24 h. The polymer was filtered off and washed with 4 x 0,25 1 of ethanol for 4 x

266 30 min under constant stirring. The polymer was dried at 25 °C under atmospheric

267 pressure to constant weight. For elemental analysis, a membrane was prepared from a

268 DMF solution, which was dried under atmospheric pressure at 70 °C and finally dried

269 under atmospheric pressure at 160 °C for 10 min. The results of elemental analysis of the

270 polymer in the H⁺ form were: C 55.67 wt. %, H 5.94 wt. %, N 17.93 wt. %, P 5.46 wt.

271 %. The ion-exchange capacity of the polymer was 3.52 meq/g according to the

272 phosphorus content. 273

274 Example 9 275 A polymerization mixture consisting of 5.03 g (0.039 mol) of vinylphosphonic acid of

276 purity 84.9 %, 5.02 g (0.095 mol) of acrylonitrile, 0.0103 g of the initiator 2,2'-azobis(2-

277 methylpropanenitrile) and 50.00 g acetone was prepared. The mixture was freed of

278 oxygen by bubbling with an inert gas for 10 min, air-tightly closed and polymerized at 70

279 °C for 24 h. The polymer was filtered off and washed with 4 x 0.25 1 of ethanol for 4 x

280 30 min under constant stirring. The polymer was dried at 25 °C under atmospheric

281 pressure to constant weight. For elemental analysis, a membrane was prepared from a

282 DMF solution, which was dried under atmospheric pressure at 70 °C and finally dried

283 under atmospheric pressure at 160 °C for 10 min. The results of elemental analysis of the

284 polymer in the H⁺ form were: C 43.49 wt. %, H 5.66 wt. %, N 12.42 wt. %, P 12.93 wt.

285 %. The ion-exchange capacity of the polymer was 8.34 meq/g according to the

286 phosphorus content. 287

288 Example 10

289 Suspension polymerization of a mixture consisting of 5.04 g (0.022 mol) bis(2-

290 chloroethyl) vinylphosphonate, 5.03 g (0.050 mol) methyl methacrylate, 0.3020 g

291 ammonium peroxodisulfate and 10.23 g water was carried out. The mixture was freed of

292 oxygen by bubbling with an inert gas for 10 min, air-tightly closed and polymerized at 70

293 °C for 8 h under constant stirring with a mechanical stirrer at 700 rpm. The polymer was

294 dried at 120 °C under atmospheric pressure to constant weight. The results of elemental

295 analysis of the polymer in the H⁺ form were: C 45.50 wt. %, H 6.38 wt. %, P 5.50 wt.

296 %, Cl 14.06 wt. %. 297

298 Example 11

299 Precipitation polymerization of a mixture consisting of 5.02 g (0.039 mol)

300 vinylphosphonic acid of purity 84.9 %, 5.07 g (0.096 mol) acrylonitrile, 0.2400 g sodium

301 peroxodisulfate, 0.2200 g sodium disulfite and 15.00 g water was carried out. The

302 mixture was freed of oxygen by bubbling with an inert gas for 10 min, air-tightly closed

303 and polymerized at 70 °C for 24 h. The polymer was filtered off , washed with 2 x 0,5 1

304 of demineralized water for 2 x 30 min under constant stirring. The polymer was dried at

305 120 °C under atmospheric pressure to constant weight. The results of elemental analysis

306 of the polymer in the H⁺ form were: C 59.07 wt. %, H 5.84 wt. %, N 21.54 %, P 2.87

307 wt. %. The ion-exchange capacity of the polymer 1.85 meq/g according to the

308 phosphorus content. 309 310 Example 12

311 Photopolymerization was accomplished in a mixture consisting of 5.00 g (0.039 mol)

312 vinylphosphonic acid of purity 84.9 %, 5.04 g iV-vinylpyrrolidone (0.045 mol), 0.3002 g

313 benzoin ethyl ether, 0.51 g iV,JV' -methylenebisacrylamide (0.0033 mol) and 6,50 g N-

314 methylpyrrolidone. The mixture was freed of oxygen by bubbling with an inert gas for 10

315 min, cast onto a glass pad, closed and polymerized in the absence of air at 25 ⁰C for 60

316 min under UV irradiation of wavelength 354 nm at a distance of 7 cm from radiation

317 source, through a 4-mm glass. UV lamp Spectroline was used as source of UV radiation.

318 The polymer membrane obtained was immersed into 50% H₃PO₄ for 1 h, washed with 2

319 x 0.5 1 of demineralized water for 2 x 30 min under constant stirring. The membrane was

320 dried at 120 °C under atmospheric pressure to constant weight. The results of elemental

321 analysis of the polymer in the H⁺ form were: C 40.60 wt. %, H 6.25 wt. %, N 6.45 wt. %,

322 P 14.32 wt. %. The ion-exchange capacity of the polymer was 9.25 meq/g according to

323 the phosphorus content. 324

325 Example 13

326 A water-soluble polymer was prepared from a polymerization mixture consisting of 5.05

327 g (0.040 mol) of vinylphosphonic acid of purity 84.9 %, 5.02 g JV-vinylpyrrolidone

328 (0.045 mol), 0.1002 g of the initiator 2,2'-azobis(2-methylpropanenitrile) and 50.00 g N-

329 methylpyrrolidone. The mixture was freed of oxygen by bubbling with an inert gas for 10

330 min, air-tightly closed and polymerized at 70 °C for 58 h. The polymer was precipitated

331 into 0.5 1 of acetone. The polymer was filtered off and washed with 2 x 0.5 1 acetone for

332 2 x 30 ml under constant stirring. The polymer was dried at 120 °C under atmospheric

333 pressure to constant weight. The results of elemental analysis of the polymer in the H⁺

334 form were: C 36.71 wt. %, H 6.06 wt. %, N 4.45 wt. %, P 18.78 wt. %. The ion-

335 exchange capacity of the polymer was 12.12 meq/g according to the phosphorus content. 336

337 Example 14

338 Emulsion polymerization was performed of a reaction mixture consisting of 10.8 g

339 (0.085 mol) vinylphosphonic acid of purity 84.9 %, 90.1 g (0.90 mol) methyl

340 methacrylate, 8.41 g of a 24% solution of sodium dodecyl sulfate as emulsifier, 1,00 g of

341 the initiator ammonium peroxodisulfate and 230 g water. The mixture was freed of

342 oxygen by bubbling with an inert gas. The polymerization was carried out in a reaction

343 vessel of ca. 400 ml volume. The vessel was charged with 20 % of the total amount of

344 water thermostatted at 80 ⁰C and kept under inert atmosphere of argon. The rest of water 345 was intensively stirred with the monomers, emulsifier and 0.4 g of ammonium

346 peroxodisulfate under the formation of monomer emulsion. 0.1 g of ammonium

347 peroxodisulfate was added shortly before dosing the monomer emulsion into the reaction

348 vessel. The emulsion was dosed in two steps. The first dose of 10 % of the dose led to the

349 formation of seeds. After 1 h the rest of emulsion was dropped into the polymerization

350 mixture in the course of 3 h. When the dropping was finished, the rest of the initiator was

351 added into the reaction vessel and the reaction temperature was increased to 90 °C. This

352 phase took 2 h. The formed emulsion was coagulated. The polymer was dried at

353 laboratory temperature. For elemental analysis, a membrane was prepared from a DMF

354 solution, which was dried under atmospheric pressure at 70 °C and finally dried under

355 atmospheric pressure at 160 °C for 10 min. The results of elemental analysis of the

356 polymer in the H⁺ form were: C 61.83 wt. %, H 8.52 wt. %, P 0.36 wt. %. The ion-

357 exchange capacity of the polymer was 0.21 meq/g according to the phosphorus content. 358

359 Example 15

360 The polymer prepared according to Example 1 was dissolved in dimethylformamide to

361 make a 10% solution. The solution was cast onto a glass as a thin film. The solvent was

362 evaporated at 70 °C and the membrane was peeled off by immersing onto demineralized

363 water. The ion-exchange capacity of the membrane was 3.25 meq/g according to the

364 phosphorus content. 365

366 Example 16

367 The polymer prepared according to Example 1 was milled in a ball mill and sieved. The

368 fraction of particles smaller than 63 μm was isolated. 35 g of a mixture of 66 wt.% of the

369 polymer particles and 34 wt.% of LLD PE was kneaded at 150 ⁰C in a Brabender Plasti-

370 Corder PLE 651 device at 30 rpm for 5 min after the torque reached 25 Nm. The mixture

371 was then pressed at 150 ⁰C between polyester films into 0,2 mm films using a final force

372 of 175 kN, 2-min precuring and 2-min coining. The area of the thus prepared membrane

373 was 315 cm². The ion-exchange capacity of the membrane was 2.15 meq/g according to

374 the phosphorus content. 375

376 Example 17

377 The polymer prepared according to Example 1 was milled in a ball mill and the fraction

378 smaller than 63 μm mesh was isolated. 1.2 g of the particles was dispersed in 10 g of a

379 12% solution of polyisobutylene in toluene and the mixture ws cast onto a glass. Toluene 380 was evaporated and the membrane peeled off by immersing into water. The ion-exchange

381 capacity of the membrane was 1.63 meq/g according to the phosphorus content. 382

383 Example 18

384 The polymer prepared according to Example 1 was dissolved in dimethylformarnide

385 (DMF) to make a 10% solution. 1 g of the solution was mixed with 1 g of 10% solution

386 of poly(vinylidene fluoride) in DMF and cast onto a glass as a thin film. The solvent was

387 evaporated at 90 °C under atmospheric pressure and the film was finally dried under

388 atmospheric pressure at 160 °C for 30 min. The membrane was peeled off by immersing

389 into demineralized water. The ion-exchange capacity of the membrane was 1.63 meq/g

390 according to the phosphorus content. 391

392 Example 19

393 The membrane prepared according to Example 15, weighing 1.43 g in the dry state, was

394 immersed into 50% phosphoric acid at 25 °C for 2 h. Then it was taken out, wiped with a

395 cellulose pad and dried at 110 ⁰C to constant weight. The amount of sorbed phosphoric

396 acid was 2.83 g.

397 Utility in industry

398 At present ion-exchange membranes find applications on laboratory and industry scale.

399 Electrochemical desalting of seawater and brackish waters, separation of electrolytes

400 from nonelectrolytes, purification of pharmaceutical preparations, solid electrolytes and

401 other processes rank among the most important applications.The materials according to

402 the present invention are designed for preparation of homogenous and heterogenous

403 membranes and for use in fuel cells and other processes utilizing ion-exchange materials.

404

Claims

415 PATENT CLAIMS

416 1. Polymer ion-exchange ion-conductive materials characterized in that they are formed

417 by non-grafted copolymers of phosphonic acids with polymerizable C=C bonds or their

418 derivatives with polymerizable C=C bonds, with one or more comonomers with one or

419 more polymerizable C=C bonds.

420 2. Nongrafted polymer ion-exchange ion-conductive materials according to Claim 1

421 characterized in that the polymerizable phosphonic acid includes compounds of general

422 formulas I and II or chlorides, fluorides and amides derived from the acids.

423 3. Nongrafted polymer ion-exchange ion-conductive materials according to Claims 1 and

424 2 characterized in that the comonomers with one or more C=C bonds are selected from

425 the group of vinyl halides, vinylidene halides, vinyl esters, vinyllactames, acrylic and

426 methacrylic acids, their halogen derivatives, esters, amides and nitriles of acrylic and

427 methacrylic acids and their halogen derivatives.

428 4. Nongrafted polymer ion-exchange ion-conductive materials according to Claims 1, 2

429 and 3 characterized in that they contain 1.2 - 28 wt.% of phosphorus.

430 5. Nongrafted polymer ion-exchange ion-conductive materials according to Claims 1, 2,

431 3 and 4 characterized in that they bind phosphoric acid by physical sorption.

432 6. Application of nongrafted polymer ion-exchange ion-conductive materials according

433 to Claims 1 , 2, 3, 4 and 5 in fuel cells or other electrochemical and ion-exchange devices.

434 7. Application of nongrafted polymer ion-exchange ion-conductive materials according

435 to Claims 1, 2, 3, 4, 5 and 6 in ion-echange columns, catalytic systems or electrochemical

436 devices.

14