EFFECT OF ACCELERATED EXPOSURE CONDITIONS ON THE PHOTODEGRADATION OF BPA POLYCARBONATE ABS BLENDS/

A BPA polycarbonate/ABS blend containing 2% TiO2 was exposed to xenon are irradiation under SAE J1885 conditions (quartz/borosilicate filter s), ''CRD'' conditions (borosilicate/borosilicate filters), and ASTM D 4459-86 conditions (borosilicote/soda lime filters). The results an: c onsistent with the conclusion that polycarbonate dominates the photoch emistry of polycarbonate/ABS blends under SAE J1885 and CRD xenon are exposure conditions. Exposure under ASTM D4459-86 conditions produced results similar to CRD conditions with some additional contribution at tributable to the ABS component. The ''activation spectrum'' of PC/ABS blends under CRD conditions closely resembled the sum of the activati on spectra of ABS and PC determined under similar conditions. The well -known change in mechanism that occurs when polycarbonate is exposed t o light with wavelengths < 300 nm was manifested by increased rates of yellowing, surface erosion, and loss of gloss under SAE J1885 conditi ons. Because of the mechanism change, resting under quartz/borosilicat e filtered xenon are exposure cannot be considered to be appropriate f or polycarbonate-containing formulations.