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Synthesls and Characterization of Block Copolymers consisting of Conjugated Monomers and Ethylene by Means of Active Site Modification

活性位点修饰共轭单体与乙烯嵌段共聚物的合成与表征

基本信息

批准号：
03650751
负责人：
ENDO Kiyoshi
金额：
$ 1.28万
依托单位：
Osaka City University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1992
项目状态：
已结题

项目摘要

The following results were obtained from the study on synthesis and characterization of block copolymers by means of active site modification. First, block copolymer consisting of styrene and ethylene bearing narrow molecular weight distribution has been synthesized by means of active site modification performed by the addition of t-diamines to living poly(styrene). Similarly, block copolymer consisting of isoprene and ethylene segments has been synthesized by means of "active site modification" performed by adding appropriate t-diamines such as N,N,N,N-tetramethylethylenediamine (TMEDA) and sparteine to the living polymer initiated with alkyllithium. Block copolymers formed have a relative narrow molecular weight distribution and retained the mainly 1,4-units in the microstructure of IP segment. Such block copolymerization with ethylene could not be admitted in the absence of the t-diamines and only homopolymer of isoprene was recovered. Block copolymer of ethylene and methyl methacrylate with alkyllithium complexed with tert-diamines by means of chain end modification by diphenyl ethylene was synthesized. These were applied to homopolymerization of ethylene and isoprene. The polymerization of ethylene initiated with alkyllithiums complexed by TMEDAN was studied by using ^<13>C NMR spectroscopy and GPC. In the cases of s-butyllithium and t-butyllithium, both initiation and termination chain end were determined by ^<13>C NMR spectra, and GPC elution curves of the polymers shifted to higher molecular weight side with reaction time. This suggests that the polymerization of ethylene initiated with alkylgroups in alkyllithiums and propagating species have a living nature. In the case of isoprene, the microstructure of the polymers could be controlled by the activesite modification.

通过活性中心修饰对嵌段共聚物的合成和表征进行了研究，得到了以下结果。首先，通过在活性聚苯乙烯中加入t-二胺进行活性中心修饰，合成了具有窄分子量分布的苯乙烯和乙烯嵌段共聚物。类似地，通过在烷基锂引发的活性聚合物中加入适当的T-二胺，如N，N-四甲基乙二胺(TMEDA)和斯巴豆碱，通过“活性中心修饰”的方法合成了由异戊二烯和乙烯链段组成的嵌段共聚物。形成的嵌段共聚物具有较窄的分子量分布，并保留了IP链段微观结构中主要的1，4-基团。在没有叔二胺的情况下，这种与乙烯的嵌段共聚是不能进行的，只能回收异戊二烯的均聚物。采用二苯基乙烯链端修饰的方法，合成了烷基锂与叔二胺的嵌段共聚物。并将其应用于乙烯和异戊二烯的均聚合。用核磁共振波谱和凝胶渗透色谱研究了TMEDAN络合的烷基锂引发的乙烯聚合反应。在S-丁基锂和叔丁基锂中，~(13)C核磁共振谱确定了聚合物的起始和终止链末端，随着反应时间的延长，聚合物的凝胶渗透色谱洗脱曲线向高分子量侧移动。这表明，烷基锂中烷基引发的乙烯聚合和繁殖物种具有生物性。在异戊二烯的情况下，聚合物的微观结构可以通过活性基改性来控制。