Effect of UV Exposure on Coir-epoxy Infused Particulate Composite
Abstract
Photo degradation mainly occurs in the lignin which is responsible for the colour changes. The surface becomes richer in cellulose content as the lignin degrades. In contrast to lignin, cellulose is much less prone to UV degradation. The effect of accelerated UV-aging on properties of coir-epoxy infused particulate composites has been studied. Composites are prepared by the hand layup technique at room temperature (25°C). Composites containing 15%particulates were subjected to accelerate UV-aging in a QUV weatherometer for 24 hrs. The results showed that coir-epoxy infused particulate composites displayed good UV resistance with regard to mechanical properties. The color of the coir-epoxy infused particulate composite changed from dark brown to light brown at the exposed area because of the formation of a thin, strongly degraded surface layer. Differential scanning calorimetry (DSC), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) were also carried out to assess the changes occurring during accelerated weathering. These results show the deterioration of the epoxy matrix leading to crystallization. A decrease in epoxy melting temperature was also noted, due to molecular chain scission and the formation of extraneous groups, such as carbonyls and amine.
Keywords
References
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