Identification of Dynamic Mechanical Properties of Radiation-Modified Silicone Elastomers by Dynamic Mechanical Yerzley Oscillograph

This study aims to investigate dynamic mechanical properties of platinum (Pt) catalyst cured vinyl-methyl-polysiloxane (VMQ) phenyl-vinyl-methyl-polysiloxane (PVMQ) elastomers at natural frequency and compare those properties for these two elastomer systems. It is also aimed to show the effect of radiation on dynamic mechanical properties of VMQ and PVMQ elastomers at natural frequency. First, Pt-VMQ and Pt-PVMQ elastomers’ curing conditions were determined using a moving die rheometer. Then, the cured silicone elastomers were irradiated with different doses. To show the effect of absorbed dose on the mechanical properties of both elastomer systems, stress–strain behaviors were examined using universal testing machine, and it was shown that ionizing radiation increases the tensile strength of both elastomer systems while it decreases elongation at the break value of both of them. The crosslink densities of Pt-VMQ and Pt-PVMQ elastomers were calculated to determine the effect of the absorbed dose on the network structure of elastomers. In order to determine the crosslink density of both VMQ and PVMQ elastomers, swelling degree and other relevant parameter were used, and it was shown the effect of ionizing radiation on both VMQ and PVMQ elastomers is an increase in crosslink density. To identify the effect of irradiation on the damping properties of Pt-VMQ and Pt-PVMQ elastomers at the natural frequency, dynamic mechanical properties were investigated using Dynamic Mechanical Yerzley Oscillograph (DMYO-5). As a result of this study, it has been shown that PVMQ elastomers’ dynamic mechanical properties at natural frequency are more stable against radiation than VMQ elastomers.