Synthesis of Azobenzene and Naphthopyran Based Polymers and Characterization of Their Photochromic Properties

Abstract

The optically active monomer is prepared to synthesize the target polymer which contains naphthopyran and its photochromic properties and kinetics are investigated as well. Its photochromic property was studied using UV–vis absorption spectroscopy. When we stop measuring of the UV light, the decolorization of the sample changes spontaneously in the dark because of the thermal back-reaction which occurs as open form of the naphthopyran undergoes ring closure and the polymer’s decoloration kinetics in films forms were analysed in the dark condition at room temperature after the optical intensity reached the maximum under UV irradiation. The naphthopyran polymer has showed the thermal bleaching tendency that the decoloration rate is very fast at the beginning of the thermal bleach and then gradually it became slow down.

Keywords- Photochromism, naphthopyran-containing polymer, kinetics, irradiation