Photo-oxidation of polystyrene/clay nanocomposites under accelerated UV exposure: Effect on the structure and molecular weight
✍ Scribed by Chérifa Remili; Mustapha Kaci; Souad Kachbi; Stéphane Bruzaud; Yves Grohens
- Publisher
- John Wiley and Sons
- Year
- 2009
- Tongue
- English
- Weight
- 704 KB
- Volume
- 112
- Category
- Article
- ISSN
- 0021-8995
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✦ Synopsis
Abstract
The present work investigates the effects of photo‐oxidation under accelerated UV conditions on the structure, the molecular weight and the morphology of polystyrene (PS)/organophilic montmorillonite (OMMT) at various clay contents: 2.5, 5, and 7 wt %. Fourier transform infrared spectroscopy, viscosimetry and scanning electron microscopy were used to evaluate the extent of degradation of nanocomposite samples in comparison with neat PS, up to 216 h of exposure. The study has shown that the formation rates of both carbonyl and hydroperoxide groups increase with exposure time, being much higher for PS/OMMT nanocomposites. Moreover, it is also observed that all samples exhibit a large increase in the scission index, however less pronounced for neat PS. These results clearly indicate the formation of low molecular weight products that could arise from chain scission. Further, the photo‐oxidation rate seems to be more affected by the presence of clay, which acts as a catalyst, rather than by the variation of clay contents. Finally, the degraded materials exhibit eroded surface. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009