Effect of thermo-oxidative ageing on electrical performance of low density polyethylene

摘要

A series of thermo-oxidalive degradation tests have been conducted on LDPE at different temperatures and under different environments. It can be concluded that thermo-oxidation has a strong impact on the electrical performance of the 'super clean' LDPE. The changes in electrical breakdown stress is closely associated with carbonyl groups when the samples were aged below melting temperature. At high temperatures, however, it seems that changes in electrical breakdown stress are related to total changes brought by oxidation, chain scission and crosslinking as well as reduction in crystallinity. Different behaviours for the samples aged above and below 150℃ may involve different degradation mechanisms.