Influence of Environment on Ageing Behaviour of the Polyurethane Film

Abstract

In this work, UV-Vis spectra, FT-IR spectra, colour difference, yellowness index，and SEM micrographs were used to study the accelerated ageing behaviour of polyurethane films that exposed to UV radiation, O₃ atmosphere, and UV/O₃ integrated environment. During 200 hours of exposure in three different environment, the UV absorbance, the colour difference, the yellowness, and the absorption of –NH/–OH and –C=O bands in FT-IR spectra of the films increase gradually with increasing exposure time, respectively, and the films exposed to the three environments have different colour difference, yellowness index, UV-Vis spectra, and FT-IR spectra. The films are vulnerable to degradation and yellowing in the following environment order: O₃ < UV < UV/O₃. After exposure to UV radiation or O₃ atmosphere, some degradation products and blisters are formed on the film surface. After exposure to UV/O₃ integrated environment, there are strip blisters and micro-cracks on the film surface, and exists an obvious synergism between UV radiation and O₃ atmosphere in accelerating the ageing of the polyurethane films.

DOI: http://dx.doi.org/10.5755/j01.ms.22.2.12935