Kinetics of radiation-oxidative aging of HDPE fibers with simultaneous destruction and macromolecules crosslinking

Abstract

The kinetics of strength reduction of high-density polyethylene fibers upon irradiation of air with X-rays in the range of absorbed dose rates of 0.02–15 Gy/s has been studied. It is shown that the decrease in the strength of irradiated polyethylene fibers occurs up to a certain limiting value, which depends on the dose rate and can be described by the laws of the kinetics of a reversible pseudo-first-order reaction. The proposed structural-kinetic model of radiation-oxidative aging of fibers takes into account the opposite effect of degradation and cross-linking of passing macromolecules on the strength of an oriented polymer (fiber), the relationship between the kinetics of radiation-oxidative transformations, and structural features of an oriented polymer. The model is in good agreement with the experiment and makes it possible to describe the change in the strength of the oriented polymer during the simultaneous occurrence of the processes of radiation-oxidative degradation and cross-linking of chains.