NATURAL AGEING OF STABILIZED AND UNSTABILIZED LDPE FILMS: XRD AND SEM ANALYSIS

Abstract

This article focuses on the study of both stabilized and unstabilized low-density polyethylene films aged under natural weathering in the middle of Morocco (Sidi Kacem city). The study was undertaken on three samples for each LDPE films: a new sample taken as reference; another exposed to outdoor weathering for one year; and a sample exposed for two years. The natural ageing effects were followed by analysis of the X-ray diffraction (XRD). This technique provides information on the main physical properties and evaluates the internal causes of natural ageing of our samples. The XRD patterns show, in addition to the usual peaks relative to the planes (110), (200) and (020), the emergence of the new region 37-48° including different peaks that clearly start the natural ageing. Thus, the XRD parameters indicate the increase of degree the crystallinity and crystallite size with time exposure for all LLDPE and LDPE samples. However, the results obtained by the X-ray diffraction have been confirmed by observing the morphology of the samples with scanning electron microscopy technology (SEM).