Photoisomerization study of p-phenylazoacrylanilide and its homo- and copolymers

Abstract To develop materials possessing intrinsic photoresponsive properties, a polymerizable derivative of azobenzene was synthesized. Condensation of acryloyl chloride with 4-phenylazoaniline was performed in THF with 100% conversion to the final product p-phenylazoacrylanilide. Its homopolymers and copolymers with methacrylic acid were prepared by free radical polymerization using 2,2′-azobis (2,4-dimethylvaleronitrile) as an initiator. Copolymerization reactivity ratios showed clear preference to form short sequences of polymethacrylic acid alternated by individual p-phenylazoacrylanilide residues. Photochemical interconversion between trans and cis isomers of p-phenylazoacrylanilide under UV or visible light irradiation was shown to be reversible and reproducible for the monomer as well as for the homopolymers and the copolymers with methacrylic acid.