Accelerated thermal and radiative ageing of hydrogenated NBR for DRC

The accelerated thermal and gamma radiation ageing of hydrogenated butadiene-acrylonitrile rubber (HNBR) carbon black-T80 has been studied by measuring the residual deformation under constant deflection-DRC, in air, using a relevant equation for the relaxation phenomena. The residual deformation under constant deflection during the process of accelerated ageing is increasing but the structure of the polymer answers in the proper manner to the mechanical stress. The degradation equations were obtained using the Alfrey model for the relaxation polymer, subject to compression and an Arrhenius dependence for the chemical reaction rate. The inverted relaxation time for the thermal degradation depends upon the chemical reaction rate and the dose rate of gamma radiation.