Synthesis of carbazole-based photorefractive polymers via post-azo-coupling reaction

Carbazole-based bi-functional photorefractive polymers with controlled azo group content were prepared via a postazo-coupling reaction. The polymers were characterized by IR, H-1 NMR, UV-visible, DSC and GPC. Both IR and H-1 NMR results proved that the azo group was attached to the polymer. As shown by UV-visible spectrum measurement, the azobenzene chromophore contents increased with extending the post-azo-coupling reaction time, and changed from 14% to 67% when the reaction time extended from 6 to 60 h. Molecular weight (M-w) of the polymers can reach 2.5 x 10(4) as measured by GPC, which is much larger than the polymers with similar structure prepared by direct polymerization from the corresponding functionalized macromonorners. Glass transition temperature (T-g) of the polymers increased with the azobenzene chromophore contents. (C) 2004 Elsevier B.V. All rights reserved.