Thermally stable photoaligned p-cyanoazobenzene moieties in polymer thin films

Poly(4-cyano-4'-methacryloyloxyazobenzene) displayed a slow E-to-Z photoisomerization rate and a low Z-isomer content at a photostationary state in a film. Linearly polarized 436 nm light irradiation resulted in the gradual generation of dichroism due to the reorientation of the azobenzene chromophores. The photodichroism was enhanced markedly by heating the film and not deteriorated even at 240 °C Discussion was made on the thermally enhanced photodichroism of the polymer with p-cy anoazobenzene side chains in respect to its semi-crystallinity.