Photostabilisation of the ‘‘wood-clearcoatings’’ systems with UV absorbers: correlation with their effect on the glass transition temperature.

Abstract

In an application-oriented study, the effective transition temperature Tg of organic wood-clearcoatings between a hard, glassy state and a viscoelastic and rubbery state is measured. The value of Tg is important in the eventual development of cracks and a thermomechanical analysis is used to study the photostabilisation performance of some UV absorbers. A weathering exposure test suggests that certain organic UV absorbers have quite a low Tg and may inhibit the crack formation, in contrast with inorganic UV absorbers.