Tri(4-methoxy-1-benzyloxyl)(pentamethylcyclopentadienyl)titanium(Cp*Ti(OBzOCH3)3) in conjunction with modified methylalumoxane(mMAO) was an efficient catalyst for the living polymerization of butene-1. The steric and ...Tri(4-methoxy-1-benzyloxyl)(pentamethylcyclopentadienyl)titanium(Cp*Ti(OBzOCH3)3) in conjunction with modified methylalumoxane(mMAO) was an efficient catalyst for the living polymerization of butene-1. The steric and highly electron-releasing nature of the catalyst was probably responsible for the resulting polymers with high molecular weight and narrow molecular weight distribution(Mw/Mn=1.25 to 1.36). The effects of polymerization conditions on the catalytic activity, molecular weight and stereo-regularity of the products were investigated in detail. Especially, the content of TMA in MAO used in polymerization of butene-1 had a profound influence on polymer microstructure. The structural properties of the polybutene-1 product were characterized by 13 C NMR, GPC, DSC and WAXD. The results indicated that the polybutene-1 was isotacticity-rich(at 0 ℃, [mmmm] reached up to 60.3%) and the relative content of methylene pentad sequences [mmmm] of the polymer increased with a decreasing temperature.展开更多
通过微波辅助法制备了含氟的TS-1(F-TS-1-M),并与传统方法制备的氟改性TS-1(F-TS-1-T),微波处理的TS-1(TS-1-M)和未改性TS-1进行比较. XRD、 DR UV-Vis、 XPS表明F-TS-1-M和TS-1-M分子筛上的部分非骨架钛转变为骨架钛,这是由于微波的选...通过微波辅助法制备了含氟的TS-1(F-TS-1-M),并与传统方法制备的氟改性TS-1(F-TS-1-T),微波处理的TS-1(TS-1-M)和未改性TS-1进行比较. XRD、 DR UV-Vis、 XPS表明F-TS-1-M和TS-1-M分子筛上的部分非骨架钛转变为骨架钛,这是由于微波的选择性效应可以不同程度地活化Ti—O和Si—O键;^(19)F MAS NMR证实了F-TS-1-M分子筛中氟元素是以Si-F和SiF_6^(2-)的形式存在;^(29)Si MAS NMR表明F-TS-1-M分子筛的骨架缺陷位和表面羟基减少, Py-FT-IR结果表明F-TS-1-M的Lewis酸性和疏水性高于F-TS-1-T、 TS-1-M和TS-1.在环己酮氨肟化的反应中表现出优异的催化性能.展开更多
基金the National Natural Science Foundation of China (No. 21174011)the Natural Science Foundation of Beijing, China (No. 2102036)
文摘Tri(4-methoxy-1-benzyloxyl)(pentamethylcyclopentadienyl)titanium(Cp*Ti(OBzOCH3)3) in conjunction with modified methylalumoxane(mMAO) was an efficient catalyst for the living polymerization of butene-1. The steric and highly electron-releasing nature of the catalyst was probably responsible for the resulting polymers with high molecular weight and narrow molecular weight distribution(Mw/Mn=1.25 to 1.36). The effects of polymerization conditions on the catalytic activity, molecular weight and stereo-regularity of the products were investigated in detail. Especially, the content of TMA in MAO used in polymerization of butene-1 had a profound influence on polymer microstructure. The structural properties of the polybutene-1 product were characterized by 13 C NMR, GPC, DSC and WAXD. The results indicated that the polybutene-1 was isotacticity-rich(at 0 ℃, [mmmm] reached up to 60.3%) and the relative content of methylene pentad sequences [mmmm] of the polymer increased with a decreasing temperature.
基金The financial supports from the National Natural Science Foundation of China(Project NO.21403135)Shanxi provincial key research and development plan project(NO.201603D121018-1)
文摘通过微波辅助法制备了含氟的TS-1(F-TS-1-M),并与传统方法制备的氟改性TS-1(F-TS-1-T),微波处理的TS-1(TS-1-M)和未改性TS-1进行比较. XRD、 DR UV-Vis、 XPS表明F-TS-1-M和TS-1-M分子筛上的部分非骨架钛转变为骨架钛,这是由于微波的选择性效应可以不同程度地活化Ti—O和Si—O键;^(19)F MAS NMR证实了F-TS-1-M分子筛中氟元素是以Si-F和SiF_6^(2-)的形式存在;^(29)Si MAS NMR表明F-TS-1-M分子筛的骨架缺陷位和表面羟基减少, Py-FT-IR结果表明F-TS-1-M的Lewis酸性和疏水性高于F-TS-1-T、 TS-1-M和TS-1.在环己酮氨肟化的反应中表现出优异的催化性能.
