Methylacrylate polymers with photochromic side chains containing heterocyclic sulfonamide substituted azobenzene

Abstract

Methylacrylate monomers containing azobenzene groups with heterocyclic sulfonamide: sulfisomidyne (4-amino- N-[2,6-dimethylpyrimidyn-4-yl]benzenesulfonamide) and sulfamethoxazole (4-amino- N-[5-methylisoxazol-3-yl]benzenesulfonamide) substituents were synthesized. The monomers were used for preparation of homopolymers and copolymers with butyl 2-methylacrylate and 2-ethylhexyl acrylate. The materials obtained showed photochromic properties manifested by trans–cis isomerization of the side chain azobenzene fragments induced by illumination with unpolarized and polarized light. The decrease of the absorbance of the E( trans) form at ≈450 nm was observed and the materials tested were in form of thin films deposited onto glass. The isomerization of the polymers carried out during ellipsometric measurements showed the reversibility of the process in repeated illumination cycles with green laser light. The change of refractive index caused by illumination was in the range ≈0.005–0.008 as determined by ellipsometry.