Design, synthesis and properties of polyaromatics with hydrophobic and hydrophilic long blocks as proton exchange membrane for PEM fuel cell application

A series of the poly(ether ether ketone)s with hydrophobic and hydrophilic long blocks were successfully synthesized by nucleophilic displacement condensation. The polyaromatics with different size of sulfonic acid group clusters were cast from their solutions to produce accordingly membranes. The comprehensive properties of these membranes were then fully characterized by determining the ion-exchange capacity, water uptake, proton conductivity, dimensional stabilities and mechanical properties. The experimental results show that the main properties of the membrane can be tailored by changing the cluster size of sulfonic acid groups or the length of hydrophilic units. The membrane of Block-6c has good mechanical, oxidative and dimensional stabilities together with high proton conductivity (2.09 × 10−2 S cm−1) at 80 °C under 100% relative humidity. The membranes also possess excellent thermal and dimensional stabilities, therefore, these polymers are potential and promising proton conducting membrane material for PEM full cell applications.