Hydrogels of dimethylaminoethyl acrylate methyl chloride quaternary salt (Q9) have been synthesized with different monomer ratio by copolymerization of this poorly studied monomer either with acrylic acid or with 2-me...Hydrogels of dimethylaminoethyl acrylate methyl chloride quaternary salt (Q9) have been synthesized with different monomer ratio by copolymerization of this poorly studied monomer either with acrylic acid or with 2-methylene bu-tane-1,4-dioic acid. Hydrogel swelling was measured as a function of the composition of the hydrogel and of the crosslinking agent ratio. High values of swelling have been obtained at very high crosslinking values (【14 wt %) and the equilibrium swelling was reached at very low time (less than 15 minutes). The swelling isotherms consisted of a steep initial portion and then levelled off as asymptotically to the equilibrium swelling limit. The experimental data suggest clearly that the swelling process obeys second-order kinetics. According to this, the kinetics rate constant and the equilibrium water content were determined at different comonomer composition and crosslinker concentration. The calculated kinetic constants ranged from 0.48 to 3.76 ×10-2 min-1 for poly (acrylic acid-co-Q9) hydrogels and from 0.68 to 4.0 ×10-2 min-1 for poly (2-methylene butane-1,4-dioic acid-co-Q9) hydrogels depending on the hydrogels composition. The diffusion process was evaluated for each hydrogel showing a non-Fickian type diffusion. In all cases was observed a considerable increase in diffusion coefficient as Q9 content increases.展开更多
A novel UV-curable oligmer 1,4-cyclohexanedimethanol glycidyl ether acrylate（CHDMGEA） was synthesized by utilizing 1,4-cyclohexanedimethanol glycidyl ether（CHDMGE） and acrylic acid（AA） as starting materials, tri...A novel UV-curable oligmer 1,4-cyclohexanedimethanol glycidyl ether acrylate（CHDMGEA） was synthesized by utilizing 1,4-cyclohexanedimethanol glycidyl ether（CHDMGE） and acrylic acid（AA） as starting materials, triphenyl phosphine as catalyst and p-hydroxyanisole as inhibitor. The optimum synthetic conditions were that the concentration of triphenyl phosphine was 0.90% of reactants by weight, the concentration of p-hydroxyanisole was 0.20% of reactants by weight, the reaction temperature was 90-100 ℃, and the molar ratio of CHDMGE to AA was 0.5：1.1. The experimental results show that CHDMGEA is a kind of good UV-curable oligmer. The impact resistance of the UV-cured films with CHDMGEA as oligmer to prepare UV-curing coating was superior to that of the UV-cured films with bisphenol A diglycidyl ether diacrylate（BPGEA） as oligmer to prepare UV-curing coating.展开更多
合成了一种新型感光性单体丙烯酸(4 N,N 二甲氨基肉桂酰氧乙基)酯(DMACEA)及其与丙烯酸的共聚物P(DMACEA co AA).用紫外吸收和荧光光谱研究了聚合物溶液的光敏感性,用傅立叶红外光谱研究了聚合物成膜后的光交联性及其过程.结果表明:DMA...合成了一种新型感光性单体丙烯酸(4 N,N 二甲氨基肉桂酰氧乙基)酯(DMACEA)及其与丙烯酸的共聚物P(DMACEA co AA).用紫外吸收和荧光光谱研究了聚合物溶液的光敏感性,用傅立叶红外光谱研究了聚合物成膜后的光交联性及其过程.结果表明:DMACEA具有较好的光敏性,P(DMACEA co AA)具有较好光交联性,交联膜水溶胀和透光性也较好.展开更多
High dispersed carbon black was applied for LiFePO4 cathodes as conductive agent.Nano-conductive carbon agent was pre-dispersed with poly acrylic acid(PAA) as dispersant in organic N-methyl-pyrrolidone(NMP) solvent sy...High dispersed carbon black was applied for LiFePO4 cathodes as conductive agent.Nano-conductive carbon agent was pre-dispersed with poly acrylic acid(PAA) as dispersant in organic N-methyl-pyrrolidone(NMP) solvent system.The dispersion property of nano-conductive carbon agent was evaluated using particle size distribution measurements,scanning electron microscopy(SEM) and transmission electron microscope(TEM).LiFePO4 cathode with as-received nano-conductive carbon agent(SP) and LiFePO4 cathode with pre-dispersed nano-conductive carbon agent(SP-PAA) were examined by scanning electron microscopy(SEM),cyclic voltammetry(CV),electrochemical impendence spectroscopy(EIS) and charge/discharge cycling performance.Results show that the dispersion property of carbon black is improved by using PAA as the dispersant.The LiFePO4 cathodes with SP-PAA exhibit improved rate behaviors(4C,135.1 mAh/g) and cycle performance(95%,200 cycles) compared to LiFePO4 cathodes with SP(4C,103.9 mAh/g and 83%,200 cycles).Because pre-dispersed carbon black(SP-PAA) is dispersed homogeneously in the dried composite electrode to form a more uniform conductive network between the active material particles,electrochemical performances of the LiFePO4 cathodes are improved.展开更多
Carbon-13 NMR has become a powerful technique in studying polymer structures. A lot of parameters which are important in elucidating polymer structure can be obtained through 13C NMR analysis. Moreover, statistical be...Carbon-13 NMR has become a powerful technique in studying polymer structures. A lot of parameters which are important in elucidating polymer structure can be obtained through 13C NMR analysis. Moreover, statistical behavior of monomer addition process can be inspected.展开更多
文摘Hydrogels of dimethylaminoethyl acrylate methyl chloride quaternary salt (Q9) have been synthesized with different monomer ratio by copolymerization of this poorly studied monomer either with acrylic acid or with 2-methylene bu-tane-1,4-dioic acid. Hydrogel swelling was measured as a function of the composition of the hydrogel and of the crosslinking agent ratio. High values of swelling have been obtained at very high crosslinking values (【14 wt %) and the equilibrium swelling was reached at very low time (less than 15 minutes). The swelling isotherms consisted of a steep initial portion and then levelled off as asymptotically to the equilibrium swelling limit. The experimental data suggest clearly that the swelling process obeys second-order kinetics. According to this, the kinetics rate constant and the equilibrium water content were determined at different comonomer composition and crosslinker concentration. The calculated kinetic constants ranged from 0.48 to 3.76 ×10-2 min-1 for poly (acrylic acid-co-Q9) hydrogels and from 0.68 to 4.0 ×10-2 min-1 for poly (2-methylene butane-1,4-dioic acid-co-Q9) hydrogels depending on the hydrogels composition. The diffusion process was evaluated for each hydrogel showing a non-Fickian type diffusion. In all cases was observed a considerable increase in diffusion coefficient as Q9 content increases.
基金Funded by the Natural Science Foundation of Jiangxi Province(20142BAB206029)
文摘A novel UV-curable oligmer 1,4-cyclohexanedimethanol glycidyl ether acrylate（CHDMGEA） was synthesized by utilizing 1,4-cyclohexanedimethanol glycidyl ether（CHDMGE） and acrylic acid（AA） as starting materials, triphenyl phosphine as catalyst and p-hydroxyanisole as inhibitor. The optimum synthetic conditions were that the concentration of triphenyl phosphine was 0.90% of reactants by weight, the concentration of p-hydroxyanisole was 0.20% of reactants by weight, the reaction temperature was 90-100 ℃, and the molar ratio of CHDMGE to AA was 0.5：1.1. The experimental results show that CHDMGEA is a kind of good UV-curable oligmer. The impact resistance of the UV-cured films with CHDMGEA as oligmer to prepare UV-curing coating was superior to that of the UV-cured films with bisphenol A diglycidyl ether diacrylate（BPGEA） as oligmer to prepare UV-curing coating.
文摘合成了一种新型感光性单体丙烯酸(4 N,N 二甲氨基肉桂酰氧乙基)酯(DMACEA)及其与丙烯酸的共聚物P(DMACEA co AA).用紫外吸收和荧光光谱研究了聚合物溶液的光敏感性,用傅立叶红外光谱研究了聚合物成膜后的光交联性及其过程.结果表明:DMACEA具有较好的光敏性,P(DMACEA co AA)具有较好光交联性,交联膜水溶胀和透光性也较好.
基金Project(51204211) supported by the National Natural Science Foundation of ChinaProject(2012M521543) supported by the China Postdoctoral Science Foundation
文摘High dispersed carbon black was applied for LiFePO4 cathodes as conductive agent.Nano-conductive carbon agent was pre-dispersed with poly acrylic acid(PAA) as dispersant in organic N-methyl-pyrrolidone(NMP) solvent system.The dispersion property of nano-conductive carbon agent was evaluated using particle size distribution measurements,scanning electron microscopy(SEM) and transmission electron microscope(TEM).LiFePO4 cathode with as-received nano-conductive carbon agent(SP) and LiFePO4 cathode with pre-dispersed nano-conductive carbon agent(SP-PAA) were examined by scanning electron microscopy(SEM),cyclic voltammetry(CV),electrochemical impendence spectroscopy(EIS) and charge/discharge cycling performance.Results show that the dispersion property of carbon black is improved by using PAA as the dispersant.The LiFePO4 cathodes with SP-PAA exhibit improved rate behaviors(4C,135.1 mAh/g) and cycle performance(95%,200 cycles) compared to LiFePO4 cathodes with SP(4C,103.9 mAh/g and 83%,200 cycles).Because pre-dispersed carbon black(SP-PAA) is dispersed homogeneously in the dried composite electrode to form a more uniform conductive network between the active material particles,electrochemical performances of the LiFePO4 cathodes are improved.
文摘Carbon-13 NMR has become a powerful technique in studying polymer structures. A lot of parameters which are important in elucidating polymer structure can be obtained through 13C NMR analysis. Moreover, statistical behavior of monomer addition process can be inspected.
