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).

On the influence of morphology and chemical defects on charge transport dynamics in polyethylene: thermal ageing and concentration gradient

“…In contrast, from figure 2(b), the chemical changes that are seen in the nonoxidised surface are comparatively minor. In conclusion, the chemical modifications seen on ageing are consistent with the published literature [31,[37][38][39]. Figure 3 shows the variation in the carbonyl region in more detail for the oxidised surface, together with derived CI data for both surfaces.…”

“…Figure 1 shows an infrared spectrum obtained from a reference sample, which contains the absorption bands that characterise the normal chemical structure of LDPE and HDPE. In this, the two absorption peaks at 717 cm −1 and 729 cm −1 are ascribed to the rocking vibration of the methylene groups from LDPE and HDPE [31,36], the peaks at 1377 cm −1 and 1471 cm −1 represent asymmetric and symmetric (umbrella mode) C-H bending vibrations of the methyl (CH 3 ) group, while the peaks at 2847 cm −1 and 2913 cm −1 correspond to the presence of symmetric and asymmetric-stretching of CH 2 methylene groups [36].…”

“…where A c is the area under the carbonyl peak located in the range of 1714-1726 cm −1 (C=O stretch mode) and A ref is the area of the chosen reference peaks at 2915 cm −1 (CH 2 and CH 3 symmetric and asymmetric stretch) [31]. The effect of ageing on sample chemistry was further considered using confocal microprobe Raman spectroscopy.…”