Photo-ageing of poly(butylene terephthalate) and poly(butylene terephthalate)-fibre glass systems
The photolysis and photo-oxidation mechanisms of poly(butylene terephthalate) (PBT) and poly(butylene terephthalate)-fibre glass (PBT-FG) irradiated under polychromatic light were studied. Derivatisation reactions coupled to FTIR analysis of the exposed samples permitted the identification of the various photo-products and the proposal of mechanisms. It was found that the same photo-products were formed in PBT and PBT-FG. Micro-FTIR analysis of the irradiated samples showed that the photochemical reactions were limited to a depth of 50 μm from the exposed surface, both in PBT and PBT-FG.