A novel bi-functional photorefractive acrylate polymer with pendant carbazolyl groups and azo derivatives as side chains was synthesized. Photorefractive experiments showed a high two-beam coupling gain coefficient of...A novel bi-functional photorefractive acrylate polymer with pendant carbazolyl groups and azo derivatives as side chains was synthesized. Photorefractive experiments showed a high two-beam coupling gain coefficient of 93 cm(-1), diffraction efficiency of 12% and electro-optic coefficient of 26 pm/V were obtained.展开更多
Amphoteric polymer can be used as retanning agent in leather manufacture. It is particularly useful in chrome-free tanning systems since it can regulate the charge properties of chrome-free leather and enhance the fix...Amphoteric polymer can be used as retanning agent in leather manufacture. It is particularly useful in chrome-free tanning systems since it can regulate the charge properties of chrome-free leather and enhance the fixation of anionic post-tanning chemicals in leather. However, the aggregation and precipitation of amphoteric polymer retanning agents around the isoelectric point (pI) hinder their wide application. Herein, we synthesized five amphoteric acrylic polymers (AAPs) by free radical copolymerization with acrylic acid and five different cationic acrylic monomers. The effect of cationic monomer structure on the aggregation behavior of AAPs was investigated. The aggregation of AAPs in aqueous solution showed pH and concentration dependence. Light scattering analysis showed that Poly (AA-co-MAPTAC) and Poly (AA-co-DMAPMA) were in the shape of coiled linear flexible chains with small particle size (Rg 7.6 nm and 14.8 nm, respectively) near the pI. However, Poly (AA-co-DAC), Poly (AA-co-DMC) and Poly (AA-co- DMAEMA) were in the shape of hollow spheres and exhibited serious aggregation. Quantum chemical calculations suggested that the amide groups in the cationic monomers MAPTAC and DMAPMA enhanced the nucleophilicity of AAPs. Thus the corresponding AAPs could carry a large number of cationic charges to slow their aggregation when the pH just climbed over the pI. The results are expected to provide theoretical reference for the synthesis and widespread application of AAPs.展开更多
Poly[2-（4-chlorophenyl）-l,3-dioxolan-4-yl]methyl acrylate, poly（CPhDMA）, was synthesized with radical polymerization process using 2,2＇-azobisisobutyronitrile as radical initiator in 1,4-dioxane at 60℃. The stru...Poly[2-（4-chlorophenyl）-l,3-dioxolan-4-yl]methyl acrylate, poly（CPhDMA）, was synthesized with radical polymerization process using 2,2＇-azobisisobutyronitrile as radical initiator in 1,4-dioxane at 60℃. The structure of poly（CPhDMA） was confirmed by means of UV-Vis, FT-IR, 1H-NMR, and 13C-NMR spectral techniques. The molecular weight distribution values of the polymer were determined with gel permeation chromatography （GPC）. The number-average molecular weight （Mn）, weight-average molecular weight （Mw） and polydispersity index （PDI） values of poly（CPhDMA） were determined to be 10300, 21600 and 2.097, respectively. The thermal degradation kinetics of the polymer was investigated by using TG/DTG-DTA and DSC analyses at different heating rates in dynamic nitrogen atmosphere. The apparent activation energy values obtained by Flynn-Wall-Ozawa and Friedman methods were found to be 91.68 and 85.23 kJ mo1-1, respectively, for thermal decomposition of poly（CPhDMA）. Also, the thermal degradation activation energy value of poly（CPhDMA） was calculated by using the Kissinger method based on the DTG, DTA and DSC data. Then the mechanism function of it was determined by master plots method. Finally, electrical and optical properties of poly（CPhDMA） were determined by four-point probe and UV-Vis techniques, respectively.展开更多
文摘A novel bi-functional photorefractive acrylate polymer with pendant carbazolyl groups and azo derivatives as side chains was synthesized. Photorefractive experiments showed a high two-beam coupling gain coefficient of 93 cm(-1), diffraction efficiency of 12% and electro-optic coefficient of 26 pm/V were obtained.
基金the Tianfu Ten-thousand Talents Program of Sichuan Province and the National Key R&D Program(2017YFB0308500).
文摘Amphoteric polymer can be used as retanning agent in leather manufacture. It is particularly useful in chrome-free tanning systems since it can regulate the charge properties of chrome-free leather and enhance the fixation of anionic post-tanning chemicals in leather. However, the aggregation and precipitation of amphoteric polymer retanning agents around the isoelectric point (pI) hinder their wide application. Herein, we synthesized five amphoteric acrylic polymers (AAPs) by free radical copolymerization with acrylic acid and five different cationic acrylic monomers. The effect of cationic monomer structure on the aggregation behavior of AAPs was investigated. The aggregation of AAPs in aqueous solution showed pH and concentration dependence. Light scattering analysis showed that Poly (AA-co-MAPTAC) and Poly (AA-co-DMAPMA) were in the shape of coiled linear flexible chains with small particle size (Rg 7.6 nm and 14.8 nm, respectively) near the pI. However, Poly (AA-co-DAC), Poly (AA-co-DMC) and Poly (AA-co- DMAEMA) were in the shape of hollow spheres and exhibited serious aggregation. Quantum chemical calculations suggested that the amide groups in the cationic monomers MAPTAC and DMAPMA enhanced the nucleophilicity of AAPs. Thus the corresponding AAPs could carry a large number of cationic charges to slow their aggregation when the pH just climbed over the pI. The results are expected to provide theoretical reference for the synthesis and widespread application of AAPs.
文摘Poly[2-（4-chlorophenyl）-l,3-dioxolan-4-yl]methyl acrylate, poly（CPhDMA）, was synthesized with radical polymerization process using 2,2＇-azobisisobutyronitrile as radical initiator in 1,4-dioxane at 60℃. The structure of poly（CPhDMA） was confirmed by means of UV-Vis, FT-IR, 1H-NMR, and 13C-NMR spectral techniques. The molecular weight distribution values of the polymer were determined with gel permeation chromatography （GPC）. The number-average molecular weight （Mn）, weight-average molecular weight （Mw） and polydispersity index （PDI） values of poly（CPhDMA） were determined to be 10300, 21600 and 2.097, respectively. The thermal degradation kinetics of the polymer was investigated by using TG/DTG-DTA and DSC analyses at different heating rates in dynamic nitrogen atmosphere. The apparent activation energy values obtained by Flynn-Wall-Ozawa and Friedman methods were found to be 91.68 and 85.23 kJ mo1-1, respectively, for thermal decomposition of poly（CPhDMA）. Also, the thermal degradation activation energy value of poly（CPhDMA） was calculated by using the Kissinger method based on the DTG, DTA and DSC data. Then the mechanism function of it was determined by master plots method. Finally, electrical and optical properties of poly（CPhDMA） were determined by four-point probe and UV-Vis techniques, respectively.
