Effect of radiation on mechanical properties of phenyl-vinyl-methyl-polysiloxane (PVMQ) elastomers cured with peroxide and Type I and Type II coagents

Abstract

The aim of this work was to identify the effects of radiation on the mechanical and damping properties of phenyl-vinyl-methyl-polysiloxane (PVMQ) elastomers cured thermally with peroxide in the presence of Type I and Type II coagents. In order to achieve this goal, in the first step a series of silicone mixtures was prepared by using 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane as the peroxide in combination with the following coagents (crosslinking agents): triallyl cyanurate (TAC), triallyl isocyanurate (TAIC), zinc acrylate (ZDA), and zinc methacrylate (ZDMA). In the second step, cured elastomers were irradiated with electron beams at a dose range of 0–80 kGy. In order to investigate the effect of irradiation on the mechanical properties of samples, the strain–stress behaviors were assessed, and the permanent deformation values were determined. Owing to higher levels of vinyl functionality, it has been found that the mechanical properties of systems prepared using TAC and TAIC can be increased at higher rates than those prepared using ZDA and ZDMA. As a result of the studies, it has been proved that when the PVMQ elastomer is thermally cured with peroxide and then treated with radiation the mechanical properties, i.e., modules values and damping properties, can be significantly improved. The elastomeric materials designed in this study were intended to have high damping properties. At the end of the cyclic compression analyses, it was found that the energy absorption capacity or damping properties of PVMQ elastomers follows the order of PVMQ/TAC = PVMQ/TAIC > PVMQ/ZDA = PVMQ/ZDMA > PVMQ. Taken together, the results reported in this work demonstrate that the coagent type and dose are two important parameters for controlling the damping properties of PVMQ elastomers.