COMPARATIVE STUDY OF UNSTABILIZED AND STABILIZED POLYETHYLENE AGED UNDER NATURAL WEATHERING
BY USING ATR-FTIR SPECTROSCOPY
M. Hamzah1, A. Rjeb1, D. Sqalli Houssaini1,2,
a LPTA, Faculté des Sciences Dhar El Mahraz, Université Sidi Med Ben Abdallah BP 1796 Fès Atlas, Maroc
b Département de Génie industriel, Faculté des Sciences et Techniques, Université Sidi Med Ben Abdallah BP2202 Fès
* Corresponding author. E-mail: email@example.com
Received: 07 November 2012; revised version accepted: 23 October 2013
The aim of this paper is the study of the photo-oxidation degradation effect on two samples of the same Low Density Polyethylene (LPDE) polymer. One of these two samples was stabilized by 4% of the Hindered Amine Light Stabilizers (HALS), while the other one was taken as a reference. The samples were exposed during four months to weathering effects, and the ageing process examined by the Attenuated Total Reflection Fourier Transform Infrared (ATR- FTIR) Spectroscopy. The main chemical modifications of the surface of the samples came from the formation of various kinds of vinyl and carbonyl groups identifiable in the ATR-FTIR spectra recorded on these degraded polyethylene samples.
Carbonyl and vinyl groups arise from the well known Norrish II reactions. As shown in this study, the presence of the HALS can decrease the oxidation level of the materials and contributes to the retardation of the photo-oxidation process.
Keywords: Polyethylene LDPE; HALS; Natural weathering; Photo-oxidation; ATR-FTIR spectroscopy.