An analysis of the effect of irradiance on the weathering of polymeric materials

Abstract

A physical model is proposed that describes the rate of photodegradation of a dyed polymer film as a function of the irradiance employed during exposure to radiation. Development of the model is based on photochemical behavior reported in dyes of similar chemical classes. The model accounts for the lack of reciprocity observed in the material at high levels of irradiance, where the degradation rate exhibits saturation behavior instead of a linear dependence on irradiance. The model is found to correctly predict the initial photodegradation rate for exposure at low irradiance, where linear dependence is evident. Additional phenomena that result from the radiant exposure are reported and discussed in relation to the proposed model. © Springer Science+Business Media, LLC 2009.