The effect of ultraviolet stabilizers on the photodegradation of poly(ethylene terephthalate)

The weathering behaviour of poly(ethylene terephthalate) was investigated. Samples produced by bi-axial extrusion were exposed in the laboratory for periods of up to similar to 1100 h. Films produced with different types of stabilizers (a ultraviolet absorber, carbon black and a mixture of TiO2 and BaSO4) were tested for mechanical properties and by UV-visible spectroscopy, titration, size exclusion chromatography and Fourier transform infrared spectroscopy. The results indicated that the unstabilized films are very susceptible to degradation, causing a large deterioration in mechanical properties and reduction in molecular weights. Of the stabilizers used the UV absorber was shown to be the most effective. (C) 2001 Elsevier Science Ltd. All rights reserved.