Investigation of gamma-irradiated multilayered polyethylene terephthalate/polypropylene composite film using Raman spectroscopy
The effect of gamma irradiation on a health product packaging material was investigated using Raman Spectroscopy. A multilayered polyethylene terephthalate/polypropylene composite packaging material was irradiated at doses ranging from 25 to 200 kGy. The Raman spectra of samples irradiated at 25 and 50 kGy showed a slight increase in intensity of the characteristic Raman bands of polypropylene which is mainly attributed to polymer cross-linking. At 75 kGy and higher doses, there is a decreasing trend in the Raman band intensities which may be due to oxidative degradation. The Raman intensities of the polyethylene terephthalate layer were relatively unchanged at different gamma irradiation doses. This is attributed to the presence of an aromatic ring in its structure, providing a more stable configuration.