Preparation of polytetrafluoroethylene porous membrane based composite alkaline exchange membrane with improved tensile strength and its fuel cell test

A strategy to improve the alkaline exchange membrane tensile strength was introduced based on porous PTFE and quaternized polyvinyl benzyl chloride (qPVBz/OH⁻). A thin PTFE film was used as the support to prepare the composite AAEM to improve the mechanical strength. Tensile stress tests showed 51.1 MPa which was twice that of the pure anion exchange membrane qPVBz/OH⁻. SEM observations showed that the pores of the PTFE were successfully filled with qPVBz/OH⁻ polymer and there was no structure defects in the cross-section of the resultant membrane. The synthesized composite membrane had very good thermal stability. The through plane ionic conductivity was in the range of 1.65 × 10⁻² to 2.2 × 10⁻² S cm⁻¹ in the temperature range of 25 °C–60 °C. The power density of H₂ and O₂ fuel cell gave 162 mW cm⁻².