A theoretical method to calculate the mode of polyurethane（PU） prepolymers grafted to polyacrylic（PAC） was presented. Using hydroxyethyl acrylate（HEA） as coupling agent, polyurethane-acrylics（PU-AC） hybrid lat...A theoretical method to calculate the mode of polyurethane（PU） prepolymers grafted to polyacrylic（PAC） was presented. Using hydroxyethyl acrylate（HEA） as coupling agent, polyurethane-acrylics（PU-AC） hybrid latexes were prepared with varying HEA level and the reaction of HEA with PU prepolymers at different temperatures, and PU grafted to PAC was experimentally determined. The results show that PU grafted to PAC regularly increased, and the non-grafted and linear free PU regularly decreased with increase in HEA/NCO（isocyanate group）. The grafted PU on PAC was not proportional to HEA. More than half of linear PU prepolymers were grafted to PAC when HEA was at a low level with HEA/NCO at 0.33. While grafted PU increased to 84.80%（mass fraction）, when HEA/NCO increased to 1.0. The results were interpreted based on the theoretical calculation of PU grafted to PAC by the present method.展开更多
A polystyrene（PS）/nanosilica organic-inorganic hybrid material was prepared from styrene monomer and commercial aqueous silica sol containing large amounts of Si-OH by means of emulsion polymerization. The nanosilic...A polystyrene（PS）/nanosilica organic-inorganic hybrid material was prepared from styrene monomer and commercial aqueous silica sol containing large amounts of Si-OH by means of emulsion polymerization. The nanosilica sol was modified by the addition of the reactive coupling agent methacrylexy propyltrimethoxysilane （ MPS）, and the resulting latex particles were protected by surfactants such as sodium dodecyl sulphonate（ SDS）, hydroxypropyl methyl cellulose （ HMPC）, and poly （vinylpyrrolidone） （PVP）. The effects of the type of surfactant, the amount of surfactant, and the coupling agent on the shape and stability of the resulting latex particles were investigated. The TEM observation indicates that among SDS, HMPC, and PVP, SDS is the best surfactant. When the content of SDS is 0. 5% and the amount of MPS is 7% in the system, the latex with obvious core-shell structure could be obtained. The average diameters of the monodispersed particles range from 182 to 278 nm, and the average number of silica beads for each composite are 1325 and 4409, respectively. The FrIR analysis shows that PS was chemically linked to silica through MPS. The thermal gravimetric analysis shows that when there is a higher silica content, the hybrid composites have a better heat resistance.展开更多
用甲基丙烯酸-β-羟丙酯(HPMA)与含羧基的聚氨酯预聚体反应得到双键封端的聚氨酯大单体,然后将离子化聚氨酯大单体与丙烯酸六氟丁酯(F6BA)采用乳液聚合法合成了水性聚氨酯/F6BA复合乳液(FPUL),研究了FPUL的微观结构、热性能、粒子形态...用甲基丙烯酸-β-羟丙酯(HPMA)与含羧基的聚氨酯预聚体反应得到双键封端的聚氨酯大单体,然后将离子化聚氨酯大单体与丙烯酸六氟丁酯(F6BA)采用乳液聚合法合成了水性聚氨酯/F6BA复合乳液(FPUL),研究了FPUL的微观结构、热性能、粒子形态和表面自由能。结果表明,通过聚合F6BA接枝到聚氨酯上,且复合乳液具有核壳结构,核层约237 nm,壳层约132 nm;FPUL固体具有2个玻璃化转变温度(Tg),软段的Tg为6.5℃,高于聚氨酯大单体的软段;硬段的Tg为43.8℃,低于聚氨酯大单体的硬段;当F6BA质量分数为总量的50%时,FPUL薄膜的表面自由能减至11.56 m J/m2。展开更多
基金Supported by the National Natural Science Foundation of China(No20874040)the Research Fund from University of Jinan, China(NoXKY0721)
文摘A theoretical method to calculate the mode of polyurethane（PU） prepolymers grafted to polyacrylic（PAC） was presented. Using hydroxyethyl acrylate（HEA） as coupling agent, polyurethane-acrylics（PU-AC） hybrid latexes were prepared with varying HEA level and the reaction of HEA with PU prepolymers at different temperatures, and PU grafted to PAC was experimentally determined. The results show that PU grafted to PAC regularly increased, and the non-grafted and linear free PU regularly decreased with increase in HEA/NCO（isocyanate group）. The grafted PU on PAC was not proportional to HEA. More than half of linear PU prepolymers were grafted to PAC when HEA was at a low level with HEA/NCO at 0.33. While grafted PU increased to 84.80%（mass fraction）, when HEA/NCO increased to 1.0. The results were interpreted based on the theoretical calculation of PU grafted to PAC by the present method.
基金Supported by the National Natural Science Foundation of China(No. 50373037)the Special Funds for Major State BasicResearch Projects ( No. 2005CB623802) Specialized Research Fund for the Doctoral Program of Higher Education ( No.20040335077).
文摘A polystyrene（PS）/nanosilica organic-inorganic hybrid material was prepared from styrene monomer and commercial aqueous silica sol containing large amounts of Si-OH by means of emulsion polymerization. The nanosilica sol was modified by the addition of the reactive coupling agent methacrylexy propyltrimethoxysilane （ MPS）, and the resulting latex particles were protected by surfactants such as sodium dodecyl sulphonate（ SDS）, hydroxypropyl methyl cellulose （ HMPC）, and poly （vinylpyrrolidone） （PVP）. The effects of the type of surfactant, the amount of surfactant, and the coupling agent on the shape and stability of the resulting latex particles were investigated. The TEM observation indicates that among SDS, HMPC, and PVP, SDS is the best surfactant. When the content of SDS is 0. 5% and the amount of MPS is 7% in the system, the latex with obvious core-shell structure could be obtained. The average diameters of the monodispersed particles range from 182 to 278 nm, and the average number of silica beads for each composite are 1325 and 4409, respectively. The FrIR analysis shows that PS was chemically linked to silica through MPS. The thermal gravimetric analysis shows that when there is a higher silica content, the hybrid composites have a better heat resistance.
文摘用甲基丙烯酸-β-羟丙酯(HPMA)与含羧基的聚氨酯预聚体反应得到双键封端的聚氨酯大单体,然后将离子化聚氨酯大单体与丙烯酸六氟丁酯(F6BA)采用乳液聚合法合成了水性聚氨酯/F6BA复合乳液(FPUL),研究了FPUL的微观结构、热性能、粒子形态和表面自由能。结果表明,通过聚合F6BA接枝到聚氨酯上,且复合乳液具有核壳结构,核层约237 nm,壳层约132 nm;FPUL固体具有2个玻璃化转变温度(Tg),软段的Tg为6.5℃,高于聚氨酯大单体的软段;硬段的Tg为43.8℃,低于聚氨酯大单体的硬段;当F6BA质量分数为总量的50%时,FPUL薄膜的表面自由能减至11.56 m J/m2。
