RECENT ADVANCES IN BISPHENOL-A POLYCARBONATE PHOTODEGRADATION

The mechanism of the photochemical evolution of bisphenol-A polycarbonate (PC) was probed using different FTIR and UV techniques along with several post-irradiation treatments of irradiated samples, including chemical derivatization reactions, physical treatments and mass spectrometric analysis of the low molecular weight fragments. The absorption maxima that were found in the carbonyl and hydroxyl regions of the infrared were assigned, and the corresponding photoproducts were identified. These studies show that the photochemical evolution of PC mainly involves two successive photo-Fries rearrangements, a photo-induced oxidation on the side-chain and a phenyl ring oxidation. These multiple reaction pathways are shown to be largely dependent upon the spectral distribution of the excitation light source and whether oxygen is present.