Influence of different types of UV absorber/UV stabilizer combination on the photodegradation of PC/ABS blend

The polycarbonate/poly(acrylonitrile butadiene styrene) blends, (PC/ABS), are mainly degraded by sunlight known as photodegradation when exposed to outdoor conditions. It is the ultraviolet (UV) radiation that is responsible for the degradation of the blend. To stabilize against the harmful UV radiation and to scavenge the radical species which arise from UV or thermally induced degradation of the PC or the ABS, UV absorbers, and UV stabilizers are used. In this article three different UV absorbers namely, Tinuvin 1577hydroxyphenyl triazine type, Cyasorb 5411benzotriazole type, Uvinul 3030cyanoacrylate type, and two different UV stabilizers, Tinuvin 765monomeric hindered amine type, Tinuvin 622oligomeric hindered amine were compounded in different combinations with PC/ABS blend at 240 degrees C using a twin screw extruder. Accelerated aging of the compounded sample was done by Atlas Suntest apparatus. The photodegradation studies were done using UVvis, attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, and Yellowing index measurement. The molecular weight of the compounded sample before aging was determined by gel permeation chromatography (GPC). It was found that samples protected with hydroxyphenyl triazine type UV absorber and oligomeric hindered amine show the best result for decreasing the degradation products, oxidation rate, and yellowing of the PC/ABS blend. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012