共查询到16条相似文献,搜索用时 78 毫秒
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二(2,6—二叔丁基—4—甲基苯氧基)钐配合物催化丙烯腈聚合 总被引:2,自引:2,他引:2
首次报道用稀土有机配合物作为单组份催化剂催化丙烯腈聚合,研究了聚合条件对标题化合物的催化活性和所得聚丙烯腈的分子量及其结构的影响。 相似文献
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二价芳氧钐配合物催化苯乙烯聚合齐贵中扈晶余*沈琪(中国科学院长春应用化学研究所稀土化学与物理开放实验室长春130022)(苏州大学化学系苏州)关键词钐配合物,苯乙烯,聚合1996-05-18收稿,1996-10-30修回国家科委攀登计划及国家自然科学... 相似文献
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二(叔丁基环戊二烯基)钕甲基配合物催化丙烯腈聚合 总被引:7,自引:0,他引:7
二(叔丁基环戊二烯基)钕甲基配合物催化丙烯腈聚合任劲松,扈晶余,沈琪(中国科学院长春应用化学研究所稀土化学与物理开放实验室长春130022)(苏州大学化学系苏州)关键词丙烯腈,配位聚合,钕配合物丙烯腈聚合通常采用BF_3、TiCl_4、过氧化苯甲酰 ̄... 相似文献
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研究了二茂基二价钐配合物(C5H5)2Sm(THF)作为单组分催化剂催化己内脂开环聚合反应,考察了催化剂用量、聚合反应时间、聚合反应温度对己内酯聚合反应的影响。结果表明,配合物(C5H5)2Sm(THF)对己内酯聚合有极高的催化活性且产物的数均分子量较高,当催化剂与单体摩尔比为1:5000时,聚合产率仍可达50.3%,数均分子量可高达32.4万;温度升高,聚合反应的转化率增加,聚合产物数均分子量降低;催化剂用量增加,聚合转化率增加,聚合产物分子量降低;聚合产物的分子量分布较窄;通过凝胶色谱法对聚合产物的分子量及分子量分布进行了表征。 相似文献
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[(t┐BuCp)2YCH3]2的合成及其对甲基丙烯酸甲酯的催化聚合活性扈晶余*任劲松沈琪(中国科学院长春应用化学研究所稀土化学与物理开放实验室长春130022)(苏州大学化学系苏州)关键词钇配合物,合成,聚合活性,甲基丙烯酸甲酯1996-04-18... 相似文献
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Organomanganate reagents [R3Mn]–Li+ (R = Bu, Me) were found to polymerize methyl methacrylate in the presence of potassium tert‐butylate. A conversion of the tacticity of the resulting poly(methyl methacrylate)s from heterotactic (mr = 54%) to isotactic (mm = 58%) was observed upon changing the R group of the initiator from Bu to Me. The addition of triisobutylaluminium was found to efficiently control M̄w and M̄w/M̄n of the resulting polymers. 相似文献
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近年来 ,有许多文献报道茂金属催化剂的负载化及其在烯烃聚合中的应用 ,这对发展新型茂金属催化剂和开发新型高分子材料有重要意义 [1,2 ] .我们 [3]曾报道壳聚糖负载稀土催化剂用于甲基丙烯酸甲酯的配位聚合有优良性能 .以五甲基环戊二烯为配体的有机稀土配合物 ,如 [Sm H( C5Me5) ]2 ,[C5Me5]Ln Me( THF) ( Ln=Sm,Yb)等在甲苯中单组分引发甲基丙烯酸甲酯聚合及内酯开环聚合具有许多优异性能[4 ,5] ,但是经负载化的该类催化剂的聚合性能尚未见报道 .本文报道将 [C5Me5]2 Sm Me·( THF)负载于二氧化硅 ,引发甲基丙烯酸甲酯聚合的结… 相似文献
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Weidong Zhang Wei Zhang Zhenping Cheng Nianchen Zhou Xiulin Zhu 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(10):850-856
Two novel azo-containing iniferters, (4,4′-(diazene-1,2-diyl) bis(4,1-phenylene) bis(2-(diethylca-rbamothioylthio)-2-methylpropanoate (BDCMP) and 4-((4-bromophenyl)diazenyl)phenyl-2-(diethylcarbamothioylthio)-2-methylpropanoate (PDCMP) were synthesized and used successfully as the initiators for atom transfer radical polymerization of methyl methacrylate (MMA). The kinetic plots were first order and the molecular weights of the polymers with narrow molecular weight distributions increased with the monomer conversions. Furthermore, the results showed that the apparent initiation efficiencies (f was close to 0.90 defined as M n(th)/M n(GPC)) of BDCMP and PDCMP were both higher than that (f was lower than 0.5) of 2-N,N-(diethylamino)dithiocarboyl-isobutyrate (EDCIB), which was reported previously by us (14). The obtained mono- and bi-functional PMMAs containing azo and N,N-diethyldithiocarbamate (DC) groups were confirmed by 1H-NMR and ultraviolet absorption spectra, respectively. The block copolymer, poly (methyl methacrylate)-b-polystyrene (PMMA-b-PS), was also successfully prepared via the ATRP chain-extension experiment using the obtained PMMA as a macroinitiator. 相似文献
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Ln(acac)3—BuMgCl催化甲基丙烯酸甲酯聚合 总被引:2,自引:0,他引:2
开发了催化甲基丙烯酸甲酯聚合的一类新型催化剂,由稀土乙酰基丙酮配合物Ln(acac)3和格氏试剂BuMgCl组成.研究了不同稀土元素、催化剂陈化时间和温度、溶剂、CCl4添加剂、聚合时间和温度的影响.结果表明,在石油醚中单体聚合转化率和聚合物相对分子质量高于芳烃和其它极性溶剂,过量BuMgCl可能起链转移作用,降低温度可提高聚合物的间同含量. 相似文献
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Shi Zhen CHEN Yun Peng BAI Zhao Long LI 《中国化学快报》2006,17(2):258-260
Fluorous-phase chemistry is currently a topic of considerable interest1-6. Since fluoroustriphasic reactions were first described by the Curran and co-workers7, this triphasicsystem has been widely used for detagging7,8 and phase-vanishing reactions9-11. … 相似文献