PHOTOLYSIS AND PHOTOOXIDATION OF POLY(BUTYLENE TEREPHTHALATE) FIBER GLASS SYSTEMS

The photooxidation and photolysis of poly(butylene terephthalate)-fibr e glass (PBT-FG) were studied, and a comparison with the photochemical behaviour of PET was made. It was found that the same photoproducts w ere formed in PET and PBT-FG, and that fibre glass had no influence on the different routes involved in the mechanisms of photolysis and pho tooxidation. The determination of the photoproduct concentration profi les in PBT-FG and PET showed that photooxidation and photolysis were l imited to a depth of 50 mu m in the irradiated surface. Moreover, it w as found that the ratio between the rates of formation of the photopro ducts in PBT-FG and PET was equal to the ratio between the contents of PET in PBT-FG and pure PET.