Synthesis and Evaluation of Novel Sulfonated Polysulfones for Proton Exchange Membrane Fuel Cell

A novel structure of sulfonated polysulfone was studied for application as fuel cell membrane. Firstly, a novel asymmetric diol (A-S-AF) was synthesized based on reaction of bisphenol A and bisphenol AF with difluorodiphenylsulfone. The successful synthesis of the monomer was confirmed by Fourier transform infrared (FT-IR) and proton nuclear magnetic resonance (۱H-NMR) spectroscopies. In the next step, sulfonated random polymers with ۳۰ and ۴۰% degree of sulfonation were prepared via polycondensation reaction of the synthesized A-S-AF diol with sulfonated and non-sulfonated difluorodiphenylsulfone. The structures of polymers were also confirmed by spectroscopic methods. The results of thermal and mechanical properties as well as IEC, water absorption, and proton conductivity measurements showed the capability of the developed polymers for fuel cell performance. The mechanical strength of ۵۳.۰ MPa and elongation of ۲۴.۲%, proton conductivity of ۰.۰۶۳ and ۰.۰۸۱ at ۲۵ and ۸۰ oC, respectively, and high thermal stability of the sample with ۴۰% degree of sulfonation were the validations.

Keywords:

Fuel cell , Membrane , Polysulfone , asymmetric diol.