Dielectric and mechanical properties in the photodegradation of poly(vinyl butyral) films

Abstract

The dielectric behaviour of unirradiated and irradiated PVB films, using UV radiation, was investigated as a function of temperature and frequency. The results obtained are discussed in terms of the dielectric parameters ε max H , Δε, β and ΔE. These experimental results, in combination with the temperature dependence of dynamic mechanical measurements in the tensile mode and with d.s.c measurements, show that during UV irradiation of PVB, besides other changes, cross-linking predominates. A mechanism of photodegradation has been proposed and is supported by gel content determination and IR spectra.