Copolymerization of Ethene with Styrene Using Methylaluminoxane-Activated Bis(phenolate) Complexes
Copolymerization of Ethene with Styrene Using Methylaluminoxane-Activated Bis(phenolate) Complexes
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DOI：
10.1021/ma961443j
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发表时间：
1997-03
期刊：
影响因子：
5.5
通讯作者：
F. G. Sernetz;R. Mülhaupt;S. Fokken;J. Okuda
中科院分区：
文献类型：
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作者：
F. G. Sernetz;R. Mülhaupt;S. Fokken;J. Okuda
用不同的二酚酸钛配合物[R1(4,6- r2c6h2 -O)2]TiX2 （R1 = CH2, C2H4， S， SO; R2 = CH3, t-Bu; X = Cl， O(i-Pr)）与苯乙烯共聚乙烯。考察了配体取代模式和聚合条件对催化剂活性、聚合动力学、苯乙烯掺入量、分子质量和共聚物微观结构的影响。催化剂活性随苯乙烯浓度的降低而升高，并受桥接基团R1类型的影响，桥接基团R1的活性等级为R1 = S > SO > C2H4。苯乙烯掺入的趋势相反，当R1 = C2H4时苯乙烯含量最高。聚合动力学主要取决于复合结构，聚合条件对聚合动力学的影响很小。一般来说，单体进料中苯乙烯的含量必须大于90 mol %，共聚物中苯乙烯的掺入量必须大于20 mol %。计算了其共聚参数。
Ethene was copolymerized with styrene using different titanium bis(phenolate) complexes [R1(4,6-R2C6H2-O)2]TiX2 (R1 = CH2, C2H4, S, SO; R2 = CH3, t-Bu; X = Cl, O(i-Pr)) activated with methylaluminoxane. The influence of ligand substitution pattern and polymerization conditions on catalyst activity, polymerization kinetics, styrene incorporation, molecular mass, and copolymer microstructure was investigated. Catalyst activity increased with decreasing styrene concentration and was affected by the type of the bridging group R1 with an activity rating of R1 = S > SO > C2H4. The opposite trend was observed for styrene incorporation where R1 = C2H4 gave the highest styrene content. Polymerization kinetics primarily depended upon complex structure and was only marginally influenced by polymerization conditions. As a rule, styrene contents of more than 90 mol % in the monomer feed were needed to achieve more than 20 mol % styrene incorporation in the copolymer. Copolymerization parameters were calculated for eth...