Preparation and Characterization of A Semi-interpenetrating Network Alkaline Anion Exchange Membrane

A series of semi-interpenetrating network (semi-IPN) anion exchange membranes (QCS/St-G(8-2-8), Quaternized chitosan/styrene-[maleic alkylene group diethyl bis (octyl dimethyl chloro/bromide), abbreviated as G(8-2-8)] were prepared via in-situ polymerization by Styrene (St) and G(8-2-8) in QCS casting solution. During the process of in-situ polymerization, linear block polymers (St-G(8-2-8)) of Styrene and G(8-2-8) was constructed, then was mixed with QCS casting solution, followed crosslinking the QCS by glutaraldehyde (GA). With the increasing content of linear block polymer, water uptake and swelling ratio of the composite membrane decreased; This kind of linear structure makes an order arrangement of quaternary ammonium groups which improves the OH- migration efficiency. At 70 A degrees C, the M-30 composite membrane performs a high OH- conductivity of 8.20x10(-2) S center dot cm(-1), the methanol permeability is 3.23x10(-6) cm(-2)center dot s(-1) which is still lower than Nafion 115 of 2.42x10(-6) cm(-2)center dot s(-1), but M-30 shows a higher selectivity of 25.3 than Nafion 115 of 11.6. Furthermore, the membranes exhibited excellent thermal stability (>= 150 A degrees C), the tensile strength of the composite membrane is in the range of 14-25 MPa and elongation at break is in the range of 16-37 % at room temperature, as well as superior chemical stability in 1.0 M KOH solution for 250 h.