Environmental degradation of stabilized LDPE. Initial step

Abstract

The environmental degradation of a stabilized low density polyethylene film was studied. The polymer degradation has started in the first 2400 h of exposure. Irregular changes in tensile strength and elongation at break up to exposure times of 7080 h are observed. A constant reduction of the mechanical properties studied begins at 7080 h of exposure. The relative optical density of the carbonyl and vinyl groups increases regularly during the whole exposure time, while a small change in the relative optical density of the vinylidene groups is observed. The thermal oxidation strength decreases after 7080 h of exposure. The crystallinity remains steady. Reflection infra-red-Fourier Transform measurements indicate that the oxidation reaction proceeds at the same rate on both sides of the film.