Photoinduced Optical Anisotropy in Modified Polyimides

New poly(amide-imide)s containing cinnamoyl and azobenzene units have been synthesized by direct polycondensation reaction of two diacids having preformed cinnamoyl units and a diamine incorporating azobenzene groups, using triphenyl phosphite and pyridine as condensing agents. The polymers were readily soluble in various organic solvents and gave thin films by casting from such solutions. They showed good thermal stability. A highly anisotropic optical film was fabricated by irradiation with linearly polarized light and its stability was studied