Mechanical Behavior of Nafion and BPSH Membranes

A brief characterization of the mechanical behavior of Nafion® 117 and BPSH-35 membranes took place through uniaxial loading, stress relaxation, and creep compliance tests. Membranes were subjected to uniaxial loading at various strain rates to observe yield and fracture behavior. Stress relaxation tests measured relaxation response to strain rate and relaxation strain. Creep compliance tests led to the formation of a creep master curve for the Nafion® membrane. Tests showed that for Nafion®, higher strain rates produced higher yield stresses and yield strains as well as faster initial relaxation. Strain rate had no effect on strain at fracture. Higher re­ laxation strains also led to faster initial stress relaxation in both Nafion® and BPSH. BPSH results showed no yield trends in uniaxial loading, though they illustrated lower breaking strains with higher strain rates.