Synthesis and characterization of sulfonated fluorene-containing poly(arylene ether ketone) for proton exchange membrane

A series of fluorene-containing poly(arylene ether ketone)s were synthesized and sulfonated using chlorosulfonic acid and then were cast into membranes from their solutions. The ionic exchange capacity, sulfonation degree, water-uptake properties, mechanical properties, thermal stabilities, and oxidative stabilities as well as conductivities were fully investigated. It was found that their conductivities increased continuously with the increasing of temperature up to 100 °C at 100% relative humidity. The proton conductivity of the membrane was determined to be close to that of Nafion-117 at 100 °C under the same testing conditions, together with the comprehensive properties for proton exchange membrane.