Photo-induced Structural Changes in Polyolefin-nanoclay Composite

The morphology of films prepared by melt-blending polyethylene (PE) and polypropylene (PP) withand without nanoclay was investigated after exposure to outdoor solar radiations for 45 days utilising manytechniques. The Raman spectra revealed decreased intensity for all the characteristic Raman bands for PP andPE. The Fourier transform infrared spectroscopy showed formation of hydroxyl/hydroperoxy and carbonylgroups in the exposed samples. The weathered films after 45 days of solar exposure became brittle as indicatedby loss in physical properties and the stress-strain curves. The clay-containing films showed higher strengthloss after solar exposure. The fractured ends of the exposed films showed flat, smooth, and sharp surfaces,indicative of brittle fracture, compared to the unexposed sample.Defence Science Journal, 2008, 58(6), pp.778-784, DOI:http://dx.doi.org/10.14429/dsj.58.1707