Synthesis of photochromic diarylethene polymers for a write-by-light/erase-by-heat recording system

A functionalized styrene monomer (1a) having a photochromic diarylethene chromophore with functional properties of photocoloration, photostability of the colored state, and thermal erasion by heating was synthesized, and the polymer and copolymers of 1a were prepared by radical polymerization and copolymerization. Their polymers exhibited excellent photocoloration and rapid thermal bleaching above 150 °C in solution and in the solid state as well as the performance of the monomeric diarylethene chromophore. In addition, the colored state has a high photostability under visible room light. The diarylethene homopolymer had a glass transition temperature (T_g) as high as polystyrene. The copolymer of 1a with N-1-adamantylmaleimide exhibited extremely high T_g above 200 °C with keeping the photofunctional performance. Such photochromic polymer and copolymers with high T_g can be potentially applied to rewritable display materials and image recordings by a write-by-light/erase-by-heat system.