Reprocessing of natural and artificial UV aged acrylonitrile-butadiene-styrene

Abstract

In the present study, the influence of reprocessing of aged acrylonitrile-butadiene-styrene (ABS) was investigated on the mechanical properties, melt flow index and morphology. Virgin ABS granules were injection molded into the shapes of the tensile, flexural and impact samples to determine the mechanical, rheological and morphological properties. Then, samples were exposed to two controlled environments, namely artificial accelerated ageing in a QUV chamber (simulating outdoor weathering with alternating cycles of ultraviolet (UV) light and moisture at controlled elevated temperature) for up to 15 days and natural ageing in Gebze (Turkey) for up to 1 year between February 2019 and February 2020 to determine the effect of a long-term outdoor exposure on the properties. After these weathering stages, naturally and UV aged samples were ground and the ground samples were blended with virgin ABS polymer at different ratios (25%, 50% and 75% by weight). The mixed materials were molded again to fabricate test samples and then characterized. In conclusion, in current work, the mechanical, rheological and morphological properties of virgin, aged in outdoors for 12 months, aged in UV chamber for 15 days and blends of virgin-aged ABS were investigated. Both natural and UV ageing caused aesthetical changes. Results showed that the tensile strength, elongation at break, flexural strength, deflection and impact strength reduced after 12 months exposure to natural ageing and 15 days exposure to UV ageing. However, MFI increased after 12 months exposure to natural ageing and 15 days exposure to UV ageing. An increment in the tensile strength, elongation at break, flexural strength and deflection was found with the incorporation of virgin ABS to 12 months naturally aged and 15 days UV aged samples. It was seen that the natural ageing, UV ageing and the reprocessing did not cause a significant change in the morphology of fractured surfaces.