Degradation of photosensitized calcium carbonate filled HDPE film

Abstract

HDPE and calcium carbonate filled HDPE films sensitized with aromatic ketone and aromatic diketone were exposed outdoor for 12 weeks. The effect of calcium carbonate filler and photosensitizers and the progress of degradation were studied by measuring the changes in tensile strength, elongation at break, average molecular weight and fourier transform infrared absorption. The relative infrared absorbances of the carbonyl group increased after exposure. The tensile strength, elongation at break and average molecular weight decreased with increasing exposure time. According to the results, it was found that the HDPE film did not change significantly during the outdoor exposure. For the HDPE films filled with high contents of calcium carbonate, the degradation rate was high whereas tensile strength and elongation at break were very low after 12 weeks of exposure. Calcium carbonate content in HDPE films did not generate carbonyl group but the photosensitizer could. However, the samples containing the photosensitizers, lose their properties more than the ones without photosensitizers. Regarding the type of photosensitizers, samples sensitized with 2-methylanthraquinone show a higher degradation rate than the ones sensitized with benzophenone.