Photoinduced optical anisotropy in new polymers containing azobenzene side groups

A series of new photosensitive polymers have been synthesized by polycondensation reaction of 2,2-bis ( 3-amino-4-[(p-oxyhexyloxy-p'-butoxy)azobenzene]-phenylene) -hexafluoropropane or 2,2-bis {3-amino-4-[(p-oxybutyloxy-p'-phenyl)azobenzene]-phenylene)-hexafluoropr opane with hexafluoroisopropylidene diplithalic anhydride or with a diacid chloride containing hexafluoroisopropylidene or dimethylsilane groups. These amorphous polymers have good solubility in organic solvents and good film-forming properties. The irradiation of polymer films with linearly polarized visible light causes a reorientation of the azobenzene groups by angular-selective E/Z photoisomerization. Thus, optical anisotropy is induced in the initially isotropic films. The photoinduced dichroism in the films was measured and the results are discussed with respect to the polymer structure