Preparation And Photochromic Properties Of Polymer Containing Spirooxazine

Photochromism is referred to as a light-induced reversible transformation of a chemical species between two isomers having different absorption spectra. At least one process is the light-induced conversion reaction.In 1993,the first Photochromic Materials Symposium was convened at French,which indicates the birth of photochromics.Photochromism is an interdispline field based on the research of chemistry,physics,materials and photoelectronic technology. During the last decade,organic photochromic compounds have increasingly attracted more attention and interest of chemists and engineers due to their potential applications in optical information storage,optical filter,anti-counterfeiting,photochromic coatings and other fields, especially in optical information storage.Spirooxazine photochromic materials have been paid great attention for their superior photochromic performance. At present, the preparation and photochromic properties of many photochromic compounds and polymers were reported. However, there is still great gap from the practical application.There are two main questions: First,the fatigue resistance performance of photochromic materials is not high; secondly, the thermal stability of open form is poor.Photochromic materials are usually the form of films in practical applications, and polymer has good film-forming.Therefore, photochromic polymers are the main area of research in the field of photochromic materials.To a large extent, polymer system influences the photochromic behavior of photochromic compounds, such as the fatigue resistance performance and the thermal stability of open form.Therefore, the important research objectives of the thesis was to explore new spirooxazine polymer systems and study their photochromic properties.The synthetic methods of spirooxazine polymers were the following: (l)First, the vinyl monomer of spirooxazine was synthesized,then,polymer containing of spirooxazine was prepared by homopolymerization or copolymerization reaction.(2) By using the reaction of active groups of spirooxazine and polymer, the polymers containing of spirooxazine terminal group or side group were prepared.(3) Spirooxazine compounds were doped into the polymer systems directly.In the thesis,in order to solve the problems of photochromic materials,the copolymer containing of spirooxazine side group and varnish doped spirooxazine were developed. A large number of experimental study was done,and the novel results are list as follows:1.Three kinds of spirooxazine derivatives were prepared.They are l,3,3-trimethyl-3H-spironaphthooxazines,l-ethyl-3,3-dimethyl-9'-hydroxy-3H-spiro naphthooxazines,l-carboxyl-3,3-dimethyl-spironaphthooxazines.2.At first,acrylate monomer containing spirooxazine pendant group was synthesized.Then, photochromic vinyl-type copolymer containing spirooxazine group was prepared by free radical solution copolymerization.By controlling the reaction conditions, the copolymer composition approached alternating copolymer,and the polymer system has excellent photochromic properties.3.Spirooxazine sodium polypropylene copolymers were synthesized by free radical solution copolymerization. Spirooxazine sodium polypropylene copolymers contained not only with spirooxazine photochromic functional group, but also with hydrophilic sulfonic acid group. So it has amphiphilic character of anionic emulsifier, which opened up the application of spirooxazine photochromic materials in the aqueous environment.4. A UV-curable acrylic polyurethane (UV-PUA) lacquer film containing spirooxazine(SO) compound was prepared. Photochromic properties of the spirooxazine in the lacquer film were studied in details. It was found that the SO in UV-PUA film showed excellent photochromic properties and this character was not reported. Moreover, the fatigue resistance and room temperature stability of open form of SO in UV-PUA film was better than in SO-PMMA film.