新型限制几何构型稀土金属有机配合物催化苯乙烯与乙烯共聚合  

Novel Constrained-geometry-configuration Rare-earth Metal Precursors to Obtain Styrene-Ethylene Copolymers

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作  者:潘玉鹏[1,2] 谢鸿雁[1,2] 崔冬梅[1,3] 

机构地区:[1]中国科学院长春应化所高分子物理与化学国家重点实验室,长春130022 [2]中国科学院大学,北京100039 [3]常州储能材料与器件研究院,常州213022

出  处:《应用化学》2012年第12期1389-1393,共5页Chinese Journal of Applied Chemistry

摘  要:合成了2种限制几何构型稀土配合物(IndCH2-Py)2Sc(CH2SiMe3)(1)、(FluCH2-Py)Sc(CH2SiMe3)2(2)(Py=Pyridyl;Ind=Indenyl;Flu=Fluorenyl),在有机硼盐与烷基铝的活化下,表现出了不同的催化行为;配合物2组成的催化体系可以引发苯乙烯与乙烯共聚,得到多嵌段共聚物,共聚活性最高达1.21×103kg/(mol(Sc)·h)。该共聚物经化学溶解性实验和凝胶渗透色谱表征,证明无均聚物存在。共聚物中,聚苯乙烯链段保持间规性,并且其含量可调。由示差扫描量热法得到了不同投料比所得共聚物的熔点(237~257℃)。共聚物的相对分子质量为3.2×104~10.7×104,相对分子质量分布为2.05~2.34。Novel constrained-geometry-configuration(CGC) rare-earth metal complexes(IndCH2-Py)2Sc(CH2SiMe3)(1) and(FluCH2-Py)Sc(CH2SiMe3)2(2)(Py=Pyridyl,Ind=Indenyl,Flu=Fluorenyl) have been synthesized by treating rare-earth metal trisalkyls with CpCH2-Py(Cp=Ind,Flu) compound,and fully characterized by NMR and X-ray diffraction analyses.Upon activation with AliBu3 and [B(C6F5)4],the two compounds showed different catalytic behavior towards copolymerization.A catalytic system containing complex 2 could initiate the copolymerization between styrene and ethylene while complex 1 was inert for the same purpose.Both gel permeation chromatography(GPC) curves and solvent extraction experiments corroborated that the products were mainly consisted of copolymers with negligible by product.The catalytic system based on complex 2,not only exhibited excellent activity(up to 1.21×103 kg/(mol(Sc)·h) and selectivity for syndiospecific styrene polymerization and styrene-ethylene copolymerization,but also afforded syndiotactic styrene-styrene sequences with controllable styrene contents in the styrene-ethylene copolymers.These copolymers were further confirmed by the observation of an endothermic peak(Tm) at 237~253 ℃ in the differential scanning calorimetry(DSC) curves.These copolymers have moderate relative molecular mass(Mn=3.2×104~10.7×104) and relative molecular mass distributions(Mw/Mn=2.05~2.34).

关 键 词:稀土烷基配合物 限制几何构型 苯乙烯 乙烯共聚 间规选择性 

分 类 号:O632[理学—高分子化学]

 

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