The synthesis and free radical polymerization of the novel methacrylate monomer containing photochromic para nitroazobenzene group and the methacrylate monomer containing mesogenic group are described.The novel azo monomer and polymers were characterized by1H-NMR

IR

UV Vis

GPC

Elemental analysis

DTA and POM techniques.The polymers obtained from the copolymerization of the azo monomer and the mesogenic monomer are proved to be random copolymers and all of them show nematic liquid crystalline textures.The UV-induced trans/cis photoisomerization and the thermal back-isomerization were investigated for the azo monomer and copolymer 1 in solution and copolymer 1 in solid film and correlated with the structures of the compounds.The results indicate that both solutions of the azo monomer and the copolymer 1 and the condensed film of the copolymer 1 can undergo photoisomerization and thermal back-isomerization

and the environments of the azo group are mainly responsible for the above photochemical process.