Chain radiation-chemical cross-linking of polyethylene under high pressures

Regularities in the radiation cross-linking of low-density polyethylene under various conditions of γ-irradiation were studied. It is shown that at the 0.5 GPa pressure and 450 K the gel formation is initiated at doses of about 1 kGy, i. e. at doses 10 times as low as compared to normal conditions. Abnormally high rate of radiation cross-linking at high temperature and high pressure is an evidence of changes in the mechanism of polyethylene, radiation cross-linking, i. e. of the process transition from nonchain to chain conditions. Decrease in the potential barriers of macroradical reactions with macromolecules is the most probable reason of change in the polymer cross-linking nature