Observation and Modeling of the Effects of Temperature and UV Lights on Weathering-Induced Degradation of PC/ABS Blend for Sustainable Consumer Electronics

This study aims to develop a general model to examine the weathering-induced degradation of a polycarbonate/acrylonitrile–butadiene–styrene (PC/ABS) blend under various temperatures and UV irradiance levels. The carbonyl index (CI) was measured with respect to the diverse conditions by Fourier-transform infrared (FT-IR) spectroscopy. Then, a response surface model for the CI with respect to the temperature and UV irradiance was established. The glossiness, tensile properties, and Izod impact resistance were measured under various weathering conditions. The fracture properties were also tested using the essential work of fracture (EWF) method. The correlations between these properties and the CI were determined. The results show that the fracture toughness and crack growth resistance measured by the EWF tests were significantly reduced even at a low CI level, i.e., the early degradation stage, whereas the tensile properties and impact resistance did not noticeably change. Although the tensile properties and impact resistances maintained their initial properties until a certain CI value, the fracture characteristics degraded rapidly, even at the initial degradation level. The model was verified by comparison with samples weathered outdoors for four and six months in Seoul, Republic of Korea. It was confirmed that the model for the Izod impact strength (IZOD) with a CI function can predict the experimental IZOD data for the outdoor-weathered specimens using the predicted CI values, with an error of 5.6%.