Photorefractive Polymers And Functional Monomers And Research

In this thesis, the oxirane and azacyclo groups were introduced to the carbazole-and phenothiazine-based photorefractive functional monomers. Then the novel photorefractive poly (ethylene oxide) and poly (ethylenimine) were synthesized by cationic ring-opening polymerization. This method provided the high chromophore content in the resulted polymer. In addition, the effects of several synthetic routes to synthesize the photorefractive monomer containing oxirane group were discussed. Chemical structure and thermal performance of the obtained photorefractive monomers and polymer were characterized.In the first part, the photorefractive functional monomer containing oxriane group was obtained by the reaction of epoxy chloropropane (EPC) with the carbazole-based azobenzene monomer. And then the photorefractive poly (ethylene oxide) was synthesized by the cationic ring-opening polymerization with boron trifluoride etherate ( BTE ) as initiator. The polymer was characterized by ~1H-NMR,IR,UV-vis,GPC,DSC and TG. DSC result showed that the glass transition temperature ( T_g ) of the polymer is 93.5°C. TG result showed the polymer starts thermal degradation at 300°C, which displays the better thermal stability.In the second part, based on the success in synthesizing poly (ethylene oxide) containing azobenzene chromophore, another poly (ethylene oxide) photorefractive polymer was designed. This polymer is expected to have better PR performance. Longer alkyl chain and more polar chromophore with a stronger electron-withdrawing group were introduced to the designed monomer. The biggest challenge is how to introduce the oxirane group onto the chromophore compound. Several synthetic sequences of the monomer were tried. While, only five intermediates were obtained and their structures were characterized by ~1H-NMR. The final monomer synthesis still remains challenging.In the third part, azacyclo group was designed and introduced to a phenothiazine-based monomer. Three intermediates have been synthesized, and their structures were proved by using ~1H-NMR,IR and UV-vis spectroscopies. UV-vis spectrum shows that the chromophore compound based on a phenothiazine moiety has absorption maximum at 443 ran. Efforts still need to be given for the final monomer synthesis.