Thermal degradation of poly(vinyl cinnamate)

Abstract

The thermal degradation of poly(vinyl cinnamate), which is a representative photo-reactive polymer and a promising candidate as a rubbing-free liquid crystal alignment layer, was investigated by thermal and spectroscopic analysis to envisage the structural changes occurring during cell assembly process. Thermal analysis shows that the poly(vinyl cinnamate) is thermally stable at least upto 200 degrees C. The spectroscopic investigations indicate that above 200 degrees C the cinnamate groups are mainly broken at the carbonyl group and the detached cinnamate groups are evaporated resulting in the weight loss. The crosslinking during thermal degradation seems to be mainly caused not by the cyclobutane ring formation, which readily occurs by UV irradiation, but by the chain transfer of the thermally generated radical.