交联聚苯乙烯-丁二烯-苯乙烯双极膜的制备及其在电合成环氧丁二酸中的应用

以聚苯乙烯-丁二烯-苯乙烯（SBS）嵌段共聚物作为基膜材料，采用自由基接枝聚合反应，在SBS主链上引入丙烯酸（AA）、苯乙烯磺酸和γ-甲基丙烯酰氧基丙基三甲氧基硅烷（KH570）链段作为阳离子交换膜；引入丙烯酸二甲基胺基乙酯和KH570链段作阴离子交换膜，阴、阳离子交换膜经KH570结构中三甲氧基硅烷基团的水解缩合，得到含硅氧交联网的SBS接枝离子交换膜，用流延法制备了SBS双极膜。 测得SBS阴膜和阳膜的吸水率分别为63.9%和72.8%，SBS阴膜和阳膜的离子交换容量分别为1.51和2.71 mmol/g。 将SBS双极膜作为阴阳两室隔膜，采用钨酸钠/过钨酸钠体系由阴极间接电氧化合成了环氧丁二酸。 结果表明，以石墨为阴、阳电极，电流密度为2.0×10-2 A/cm²、50 ℃反应4 h，环氧丁二酸的产率为53.0%，电流效率为40.8%。

Preparation of Cross-linking Styrene-butadiene-styrene Triblock Copolymer Hybrid Bipolar Membrane and Its Application in Electro-generation of Trans-2,3-oxiranedicarboxylic Acid

The cross linking SBS hybrid bipolar membrane（SBS BPM） was prepared by free radical reaction of SBS(styrene-butadiene-styrene triblock copolymer) with acrylic acid(AA), sulfonic styrene(StSO3H) and γ-methacryloxypropyltrimethoxysilane(KH-570) as the anode membrane, and reaction of SBS with dimethyl amino ethyl methacrylate(DMAEMA) and KH-570 as the cathode membrane. Cross-linking reaction was carried out through sol-gel reaction of trimethoxysilane group. SBS BPM exhibited high temperature tolerance(thermal degradation temperature in N2, Td was up to 186.5 ℃). The ion exchange capacities(IECs) of the anode and cathode membranes were 1.51 and 2.71 mmol/g, respectively. SBS hybrid bipolar membranes were used as the separator in the electrolysis cell, then using tungstate/pertungstate as the media to indirect electrooxidate maleic acid to prepare trans 2,3-oxiranedicarboxylic acid in the cathode chamber. Graphite was used as the anode and cathode electrode. At 50 ℃ and when the current density was 2.0×10-2 A/cm2 for 4 h, the yield and average current efficiency of trans 2,3-oxiranedicarboxylic acid were 53.0% and 40.8%, respectively.