3-Glycidoxy-propylthrimethoxysilane improved anion exchange membranes based on quaternized poly(2,6-dimethyl-1,4-phenyleneoxide)

The organic-inorganic hybrid anion exchange membranes were prepared from quaternary triethylamonium functionalized poly(2,6-dimethyl-1,4-phenyleneoxide) (QPPO) and 3-glycidoxypropylthrimethoxysilane (GOPS) with different ratios. The obtained membranes are termed as QPPOx-Gy, where x and y are the mole ratios of triethylamine and the siloxane GOPS to the bromomethyl groups of the polymer, respectively. The resultant hybrid membranes are thermally stable up to 200 °C and exhibit a tensile stress of around 10 MPa. The incorporated GOPS endows the hybrid membranes with increased water uptake and conductivity due to the more hydroxyl groups containing in the hydrolytic networks of GOPS in the membranes. A conductivity of 46.0 mS cm−1 is achieved by the QPPO0.4-G0.55 membrane in water at 80 °C, which is about 20 mS cm−1 higher than the conductivity of the pristine QPPO0.4 membrane. In addition, the QPPO0.4-Gy hybrid membranes possess enhanced alkaline tolerance toward the attack of hydroxide ions. After soaked in 1 M KOH at 60 °C for 480 h, the hybrid membranes retained more than 16–22% of the initial conductivity compared to the pristine QPPO0.4 membrane. [Display omitted] •Novel siloxane incorporated hybrid anion exchange membranes were prepared.•The siloxane networks bring on increased hydrophilicity of the hybrid membrane.•Enhanced conductivity and tolerance to alkali of the prepared hybrid membranes.