Studies on Stereocontrol of Free-Radical Polymerization

自由基聚合立体调控的研究

基本信息

批准号：
07455370
负责人：
OKAMOTO Yoshio
金额：
$ 4.74万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

项目摘要

1. The presence of cobaltus complexes including (R,R)-N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediaminatocobalt (II) (1) was found to affect stereochemistry of free-radical polymerization of methyl, benzyl, isopropyl, and t-butyl methacrylates. In the polymerization of t-butyl ester, a decrease of 12% in rrrr pentad content was observed based on 1. Tacticity of polymers obtained from the other monomers such as vinyl acetate, stirene, and acrylates were also affected by the added radical complex where the magnitude of the effect varied depending on the combination of monomer and complex.2. Living-like propagation was demonstrated for the polymerization of methacrylates, acrylates, stirene, and vinyl acetate using cobaltus complexes although beta-hydrogen elimination (a termination reaction) took place in the methacrylate polymerization to give omega-end unsaturated polymers. In the case of acrylate polymerization, possibility of block copolymerization was suggested.3. Complexes including 1 was effective in regiochemistry control in sorbate polymerization which gives a relatively high-molecular-weight polymer with 1,4-trans structure in addition to oligomers with 1,2-or 3,4-structures having unreacted pendent vinyl group. The presence of the complex suppressed the production of the oligomers.4. Polymerization of 1-phenyldibenzosuberyl methacrylate using optically active peroxides (initiator) and thiols (chain transfer agent) based on chiral menthol gave optically active, helical polymer with excess single-handed helicity.5. Polymerization of 1-phenyldibenzosuberyl methacrylate in the presence of 1 resulted in optically active, helical polymer which gave purely single-handed helical fractions by GPC separation.

1. 钴配合物（包括 (R,R)-N,N'-双(3,5-二叔丁基水杨基)-1,2-环己烷二氨基钴 (II) (1)）的存在会影响游离钴的立体化学-甲基丙烯酸甲酯、苄基酯、异丙酯和叔丁酯的自由基聚合。在叔丁酯的聚合中，基于 1，观察到 rrrr 五单元组含量降低了 12%。由其他单体（例如乙酸乙烯酯、苯乙烯和丙烯酸酯）获得的聚合物的立构规整性也受到添加的自由基络合物的影响，其中效果的大小取决于单体和配合物的组合。2．尽管在甲基丙烯酸酯聚合过程中发生了β-氢消除（终止反应），得到了omega端不饱和聚合物，但使用钴络合物的甲基丙烯酸酯、丙烯酸酯、苯乙烯和乙酸乙烯酯的聚合反应仍表现出类生命的增长。在丙烯酸酯聚合的情况下，提出了嵌段共聚的可能性。 3．包含1的络合物在山梨酸酯聚合中的区域化学控制中是有效的，除了具有未反应的乙烯基侧基的1,2-或3,4-结构的低聚物之外，还产生具有1,4-反式结构的相对高分子量的聚合物。配合物的存在抑制了低聚物的产生。4．使用基于手性薄荷醇的光学活性过氧化物（引发剂）和硫醇（链转移剂）聚合甲基丙烯酸1-苯基二苯并辛酯，得到具有过量单手螺旋度的光学活性螺旋聚合物。5．甲基丙烯酸 1-苯基二苯并环庚酯在 1 存在下聚合产生光学活性螺旋聚合物，通过 GPC 分离得到纯单手螺旋部分。