Hybrid SBS Bipolar Membrane in Electro-Generation of HPAc and Succinic Acid. The hybrid SBS-g-(DMAEMA-SiO2)/SBS-g-(AA-StSO3Na-SiO2) bipolar membrane, SBS BPM was prepared by SBS (styrene-butadiene-styrene triblock copolymer) grafted with acrylic acid (AA), sodium sulfonic styene(StSO3Na) through free radical grafting reaction, then the grafting copolymer and mercaptopropyltrimethoxysilane (KH-590) were exposed to UV illumination, and the SiO2 doped anode membrane was obtained through sol–gel reaction of trimethoxysilane group, as similar process the cathode membrane was prepared by SBS grafted with dimethyl amino ethyl methacrylate (DMAEMA) and KH-570.

The SBS BPM exhibited good mechanical strength (tensile strength, TS is 1.55MPa) and high temperature tolerance (thermal degradation temperature in N2 is in the range of 230–250C). The ion exchange capacities (IECs) of SBS-g-(DMAEMA-SiO2) and SBS-g-(AA-StSO3 Na-SiO2) were in the region of 1.42–2.82 mmol/g. The SEM images show that the membrane cross- sections are very smooth where no silica particles could be observed. SBS-g-(DMAEMA-SiO2)/ SBS- g-(AA-StSO3Na-SiO2) bipolar membrane was used as the separator in the electrolysis cell for electro- generation of 2,2-dimethyl-3- hydroxypropionic acid(HPAc) and succinic acid(cas:110-15-6) in pairs.

The yield of HPAc and the corresponding average current efficiency in the anode chamber were 28.2% and 53.8, respectively. The yield of succinic acid(cas:110-15-6) and the average current efficiency in the cathode chamber were 74.1% and 62.5%, respectively.