Abstract:

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.

Key words: SBS hybrid bipolar membrane, indirect electrooxidate, tungstate /pertungstate, trans-oxiranedicarboxylic acid