Effect of cyclic compression and curing agent concentration on the stabilization of mechanical properties of PDMS elastomer

Under repeated deformation, the mechanical properties of polydimethylsiloxane (PDMS) elastomer evolve. This paper aims to investigate the effect of curing agent concentration on the mechanical response of PDMS elastomer under cyclic compressive loading. PDMS elastomer samples containing various curing agent concentrations were prepared following ASTM D575 standard. Three different curing agent concentrations were investigated: 6.25, 9.09 and 16.67 wt%. Monotonic compressive test up to failure and 100 cycles of cyclic compressive test were performed using Instron 3369 50 kN dual column testing machine at a constant crosshead displacement rate of 12 mm/min. It was found that the compressive modulus increases with the curing agent concentration. The effects of cyclic compression on strain hardening, compressive modulus, and creep were also investigated. Results showed that cyclic compression contributes to the stabilization of the materials. Moreover, the number of cycles required to reach strain hardening stabilization decreases as the curing agent concentration increases.