Study of natural aging of industrial low density polyethylene by X-ray photoelectron spectroscopy

Abstract

X-ray photoelectron spectroscopy (XPS) was used to study the natural outside aging of industrial low density polyethylene (LDPE) under the influence of one year round weather. Two types of LDPE were studied. The first type was LDPE without additives and the second type was doped with 4% of hindered amine light stabilisers (HALS). Unstabilised and 4% HALS stabilised LDPE samples underwent an oxidation of the polymeric matrix, by the production of C–O, C=O and O=C–O groups. These chemical functions were observed in high resolution XPS spectra around C1s and O1s peaks. From these results, it was then possible to propose mechanisms of natural aging of LDPE in such conditions. On the other hand, there is no clear evidence that HALS could be effective in natural aging for the polymer surfaces with exposure to the elements.

Keywords:

• LOW DENSITY POLYETHYLENE (LDPE)
• OXIDATION
• AGING
• XPS
• STABILISATION
• HALS