Highly Proton Conductive Poly(vinyl acetate)/Nafion® Composite Membrane for Proton Exchange Membrane Fuel Cell Application

A novel blend of membranes made of cast Nafion® and poly(vinyl acetate) (PVAc) was prepared and its proton conductivity and ion exchange capacity (IEC) were characterized to investigate its applicability in proton exchange membrane fuel cells (PEMFCs). The intermolecular interactions and morphology of these membranes were assessed using Fourier-transform infrared spectroscopy (FT-IR) and field-emission scanning electron microscopy (FE-SEM). A twofold increase in the proton conductivity is observed for the PVAc/Nafion® composite membrane (2 × 10⁻² Scm⁻¹) compared to that of cast Nafion® (1.1 × 10⁻² Scm⁻¹). In addition to that, the composite membranes exhibited better mechanical strength and adequate water retention ability as well as IEC comparable to that of cast Nafion®. The thermal property and chemical degradation property were also investigated. The results indicate that the introduction of PVAc as a modifier played a vital role in improving the membrane performance. Accordingly, these polymer electrolyte membranes with suitable PVAc contents have prospect for use in low-temperature PEMFCs.