Kinetic model for extrapolation of combined radiation-thermal accelerated aging experiments

A general theoretical model has been derived for the case of oxidative degradation dominated by the slow breakdown of hydroperoxide species. The model has been used to predict the general form of dose-rate effects for this mechanism. The model also suggests a method for creating isothermal dose-rate curves through a time-temperature dose rate superposition procedure which utilizes no adjustable parameters. The superposition procedure and the kinetic model are quantitatively verified using accelerated aging laboratory data and real-time nuclear power plant aging data on a PVC and a PE material. Although oxidative degradation is discussed in this paper, the general form of the theoretical model should allow it to be applied to oxidative crosslinking as well. 1 reference, 1 figure