Development of a light-responsive fluorinated poly(arylene ether) copolymer containing azobenzene groups in the main polymer chain†

A novel light-responsive poly(arylene ether) copolymer with both azobenzene and perfluorinated biphenylene units as well as meta-linked fragments in the main polymer chain is synthesized. The copolymer is synthesized using aromatic nucleophilic substitution reaction from decafluorobiphenyl and two dihydroxyl-substituted monomers, fluorinated bis-azobenzene-based phenol derivative, and resorcinol. The chemical structure of the copolymer is characterized using ¹H, ¹⁹F NMR, FTIR, Raman and UV/vis spectroscopy techniques. The polymer shows remarkable solubility in organic solvents resulting in the formation of robust, self-supporting films. It displays impressive mechanical characteristics as well as remarkable resistance to thermo-oxidative degradation. Under UV light irradiation, photoisomerization occurs both in solution and in the solid copolymer film. The solid polymer films exhibit intense and stable birefringence changes upon the irradiation, enabling the fabrication of diffraction gratings. The study indicates that this synthetic approach is a simple and effective method for designing light-responsive materials.