研究了一种钕催化体系——以乙醇为配体的三氟甲磺酸钕／三异丁基铝催化体系[Nd（CF3SO3）3·3H2O·C2H5OH-（i-Bu）3]催化苯乙烯（St）与异戊二烯（Ip）的共聚合行为。讨论了n（St）／n（1p）、n（Al）／n（Nd）、聚合时间等的影响。研究结果表明，该催化体系不能引发St均聚，但可实现St与Ip的共聚，共聚活性低于lp均聚活性，且强烈依赖于单体组成。共聚物的分子量达到2．9×10^6。St以单个分子或／和短嵌段的形式嵌入Ip长链段中。其中Ip单元以cis-1，4结构为主，cis-1，4的物质的量分数达91％。随着n（St）／n（Ip）增大，共聚物中St含量明显增加，但St含量的增加对Ip单元的cis-1，4含量没有影响。
In this article, copolymerization behaviors of styrene (St) and isoprene (Ip) using a rare earth catalyst system - sulfoacid neodymium Nd(CF3SO3) 3· 3H2O·C-2H5OH complex activated by Al(i-Bu) 3 were investigated. The effect of polymerization conditions, such as n (St)/n (Ip) ration, n (Al)/n (Nd) ratio and the polymerization time was studied. The results show that the given catalyst system can initiate the copolymerization of styrene and isoprene, and copolymerization activity is lower than that of isoprene homopolymerization, which is strongly dependent on monomer feed ratios. The molecular weight of copolymers can reach up to 2.9 ×10^6. A single styrene molecule or/and short styrene blocks are embedded in the long isoprene blocks chains of the copolymer. Isoprene units in this copolymer are almost cis-1,4 structure, the content of cis-l,4 is up to 91%. Styrene contents increase with the increasing of n (St)/n (Ip) raio and the polymerization time, while the contents of St incorporation have little effect on the contents of cis-1,4.
参考文献
| [1] | Kobayashi E.;Aoshima S.;Furukawa J.;Hayashi N. .Copolymerization of dienes with neodymium tricarboxylate-based catalysts and cis-polymerization mechanism of dienes[J].Journal of Polymer Science, Part A. Polymer Chemistry,1998(11):1707-1716. |
| [2] | Cuomo C;Serra MC;Maupoey MG;Grassi A .Copolymerization of styrene with butadiene and isoprene catalyzed by the monocyclopentadienyl titanium complex Ti(eta(5)-C5H5)(eta(2)-MBMP)Cl[J].Macromolecules,2007(20):7089-7097. |
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