Synthesis of fluorinated amphiphilic triblock copolymer and its application in high temperature PEMfuel cells

Abstract

New fluorinated amphiphilic triblock copolymers composed of fluorinated poly(arylene ether) and sulfonated poly(styrene-co-acrylonitrile) were synthesized through condensation polymerization followed by controlled radical polymerization, for application in polymer electrolyte membrane fuel cells. The morphological structure of the triblock copolymers was investigated as a function of hydrophilic block length, and was related to the proton conductivity and durability of the copolymer membranes. Unlike commercially available Nafion, which shows a decrease of the proton conductivity at high temperatures above 80 °C, the newly synthesized membranes exhibit high proton conductivity and continuous increases in proton conductivity with increasing temperature from 30 °C to 100 °C. They also show excellent thermal, oxidative and hydrolytic stabilities.