Accelerating effect of montmorillonite on oxidative degradation of polyethylene nanocomposites

摘要

Polyethylene, one of the most widely used packaging materials, can be made biodegradable by blending it with biopolymers such as starch and/or pro-oxidants which are metal complexes (e.g. cobalt stearate, cerium stearate). Recent studies on polyethylene degradation have found that addition of nanoclay, which is used as a filler in polymer composites mainly to enhance their mechanical properties, also increases their photo-oxidative degradation. The present study aims to investigate the degradation of low density polyethylene (LDPE) formulated with nanoclay and evaluate the effect of nanoclay compositions on the overall photo-oxidation process. Photo-oxidative aging of polyethylene and its nanocomposites were carried out in a QUV weathering tester for a maximum period of two weeks. The degradation progress was followed by monitoring the chemical changes of the samples using Fourier transform infrared spectroscopy (FTIR) and gel permeation chromatography (GPC). The results indicate that the incorporation of nanoclay significantly enhances the degradation of polyethylene.