Synthesis And Optical Properties Of Novel Naphthopyran Photochromic Polymers

Photochromic materials are widely used in optical information storage, optical switching devices and optical switches and other frontier areas. Polymer is beneficial to the manufacture of the device due to that polymer has better advantage to form film that small molecule.Naphthopyran is a kind of photochromic materials with good performance, whereas there are just several reports about naphthopyran polymers. In this work, a novel naphthopyran-containing monomer is designed and synthesized, and used to fabricate linear and cross-linked polymer photochromic materials via atom transfer radical polymerization (ATRP). Their photochromic properties were mainly evaluated using changes of absorption spectra after UV light irradiation, rate of heat achromatic, fatigue resistivity and bleaching kinetics. Meanwhile, the containing-coumarin monomer was also synthesized, which was reacted with naphthopyran-containing photochromic monomer or butyl acrylate via ATRP in order to prepare photochromic polymers with different structures and property. The experimental results indicated that the photocrosslink of coumarin in polymer decrease the rate of heat achromatic. Optical and film-forming properties of polymer can be also regulated by changing the content of naphthopyran monomer. Compared with photochromic system obtained by doping mode, optically active groups in synthesized polymers were bonded to the main chain of polymer by chemical bonds in this polymer system, so that the optical groups were not dissociate from the main body of the material.In this paper, monomers and polymers were characterized by means of NMR (1H NMR), mass spectrometry (MS), gel permeation chromatography and UV- visible absorption spectra. Optical performance was measured under the irradiation of the CHF-XM35-500W xenon lamp with a parallel light source system.