A series of polymers bearing azobenzene and carbazole groups for photorefractive purpose were prepared viapost-azo-coupling reaction.The successful reaction was identified by spectroscopic analysis and gel permeationc...A series of polymers bearing azobenzene and carbazole groups for photorefractive purpose were prepared viapost-azo-coupling reaction.The successful reaction was identified by spectroscopic analysis and gel permeationchromatography.This approach is more facile compared with the direct polymerization of corresponding functionalmonomer.The polymers prepared have weight average molecular weight of higher than 1.5×10~4 and are easily soluble incommon organic solvents like chloroform and tetrahydrofuran,polymer films with high optical quality could be easilyfabricated through solution casting.Glass transition temperature (T_(?)) of the polymers ranges from 60℃ to 182℃,dependingon the alkylene spacer length between the functional side group and the polymer backbone,and the polymers are relativelystable under 300℃.展开更多
Carbazole-based bi-functional photorefractive polyacrylates were prepared via free radical polymerization and post-azo-coupling reaction. The structure of polymers was characterized by Fourier transform infrared spect...Carbazole-based bi-functional photorefractive polyacrylates were prepared via free radical polymerization and post-azo-coupling reaction. The structure of polymers was characterized by Fourier transform infrared spectroscopy （FTIR） and proton nuclear magnetic resonance （^1H-NMR） spectroscopy. The differential scanning calorimetry （DSC） and the thermal gravimetric analysis （TGA） were used to characterize the thermal property of polymers. The results indicate that though the glass transition temperature （Tg） of polymers increases with increasing the ratio of NLO groups, the polymers with different ratios of NLO groups still all show low glass transition temperatures around 60 ℃, and good thermal stability, which are favorable to the practical application of these polymers. The gel permeation chromatographic （GPC） result indicates that these polymers all have high-molecular-weight which is favorable to the long term stability of the material. Further, these polymers have good solubility in chloroform solvent, and the solutions can easily be fabricated into optically transparent films. Gain coefficients of 75 cm^-1, 185 cm^-1 and 66 cm^-1 can be observed at zero external electric field without any addition agent or pre-poling for polymers P-2, P-3 and P-4 respectively. The different contents of NLO groups result in the different properties of polymers P-2, P-3 and P-4.展开更多
基金This work was supported by the National Natural Science Foundation of China(No.20274042)
文摘A series of polymers bearing azobenzene and carbazole groups for photorefractive purpose were prepared viapost-azo-coupling reaction.The successful reaction was identified by spectroscopic analysis and gel permeationchromatography.This approach is more facile compared with the direct polymerization of corresponding functionalmonomer.The polymers prepared have weight average molecular weight of higher than 1.5×10~4 and are easily soluble incommon organic solvents like chloroform and tetrahydrofuran,polymer films with high optical quality could be easilyfabricated through solution casting.Glass transition temperature (T_(?)) of the polymers ranges from 60℃ to 182℃,dependingon the alkylene spacer length between the functional side group and the polymer backbone,and the polymers are relativelystable under 300℃.
基金financially supported by the Innovation Foundation of China Academy of Engineering Physics(No.CX08201205)the Development Foundation of China Academy of Engineering Physics(No.2013A0302016)
文摘Carbazole-based bi-functional photorefractive polyacrylates were prepared via free radical polymerization and post-azo-coupling reaction. The structure of polymers was characterized by Fourier transform infrared spectroscopy （FTIR） and proton nuclear magnetic resonance （^1H-NMR） spectroscopy. The differential scanning calorimetry （DSC） and the thermal gravimetric analysis （TGA） were used to characterize the thermal property of polymers. The results indicate that though the glass transition temperature （Tg） of polymers increases with increasing the ratio of NLO groups, the polymers with different ratios of NLO groups still all show low glass transition temperatures around 60 ℃, and good thermal stability, which are favorable to the practical application of these polymers. The gel permeation chromatographic （GPC） result indicates that these polymers all have high-molecular-weight which is favorable to the long term stability of the material. Further, these polymers have good solubility in chloroform solvent, and the solutions can easily be fabricated into optically transparent films. Gain coefficients of 75 cm^-1, 185 cm^-1 and 66 cm^-1 can be observed at zero external electric field without any addition agent or pre-poling for polymers P-2, P-3 and P-4 respectively. The different contents of NLO groups result in the different properties of polymers P-2, P-3 and P-4.
