In this work, we report the synthesis of AB2 shaped amphiphilic azo block copolymer by macromolecular azo coupling reaction. The product and intermediates were characterized by various methods. The self- assembly in s...In this work, we report the synthesis of AB2 shaped amphiphilic azo block copolymer by macromolecular azo coupling reaction. The product and intermediates were characterized by various methods. The self- assembly in selected solvents and photo-responsive behavior of the copolymer were studied by means of UV-vis spectrophotometry and TEM. Spherical aggregates can be obtained by gradually adding water into the solution of this amphiphilic azo block copolymer. Upon irradiation with polarized UV （365 nm） light, the aggregates can be elongated in the polarized direction.展开更多
Under basic conditions, a series of 4,4-dialkylthio-l,2-diaza-l,3-butadienes were synthesized in good to excellent yields via a novel azo-coupling decarboxylation reaction by reacting a-carboxyl ketene dithioacetals w...Under basic conditions, a series of 4,4-dialkylthio-l,2-diaza-l,3-butadienes were synthesized in good to excellent yields via a novel azo-coupling decarboxylation reaction by reacting a-carboxyl ketene dithioacetals with aryldiazonium salts in aqueous medium.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
A new kind of carbazole-based photorefractive polymer was prepared via a post-azo- coupling reaction. The structure of the polymer was characterized by IR, 1H NMR, UV-vis and GPC. The IR and UV-vis spectra demonstrate...A new kind of carbazole-based photorefractive polymer was prepared via a post-azo- coupling reaction. The structure of the polymer was characterized by IR, 1H NMR, UV-vis and GPC. The IR and UV-vis spectra demonstrated that azo group was grafted to the polymer in content of 15.56%. The molecular weight of the polymer as determined by GPC was higher than that of the polymer obtained by common method.展开更多
基金supported by the National Natural Science Foundation of China (No. 21474056)
文摘In this work, we report the synthesis of AB2 shaped amphiphilic azo block copolymer by macromolecular azo coupling reaction. The product and intermediates were characterized by various methods. The self- assembly in selected solvents and photo-responsive behavior of the copolymer were studied by means of UV-vis spectrophotometry and TEM. Spherical aggregates can be obtained by gradually adding water into the solution of this amphiphilic azo block copolymer. Upon irradiation with polarized UV （365 nm） light, the aggregates can be elongated in the polarized direction.
基金Project supported by the National Natural Science Foundation of China （No. 20272008） and the Key Grant Project of Chinese Mimstry of Eucation （No. 10412）.
文摘Under basic conditions, a series of 4,4-dialkylthio-l,2-diaza-l,3-butadienes were synthesized in good to excellent yields via a novel azo-coupling decarboxylation reaction by reacting a-carboxyl ketene dithioacetals with aryldiazonium salts in aqueous medium.
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.
文摘A new kind of carbazole-based photorefractive polymer was prepared via a post-azo- coupling reaction. The structure of the polymer was characterized by IR, 1H NMR, UV-vis and GPC. The IR and UV-vis spectra demonstrated that azo group was grafted to the polymer in content of 15.56%. The molecular weight of the polymer as determined by GPC was higher than that of the polymer obtained by common method.
