cis-1,4-Selective Copolymerization of Ethylene and Butadiene: A Compromise between Two Mechanisms
cis-1,4-Selective Copolymerization of Ethylene and Butadiene: A Compromise between Two Mechanisms
复制标题
乙烯和丁二烯的顺式1,4-选择性共聚：两种机制之间的折衷
DOI：
10.1002/anie.201702128
复制
发表时间：
2017
影响因子：
16.6
通讯作者：
Cui Dongmei
中科院分区：
文献类型：
--
作者：
Wu Chunji;Liu Bo;Lin Fei;Wang Meiyan;Cui Dongmei
在聚丁二烯主链中引入乙烯单元是合成先进橡胶材料的一种方法，但由于这两种单体的聚合机理不同，这一直是一个研究挑战。到目前为止，只得到了反式-1，4-和1，2-调节的共聚物。在这里，我们报道了前所未有的顺式-1，4选择共聚的乙烯和丁二烯，使用噻吩环戊二烯连接的钪配合物。考察了催化前驱体的空间构型、电子结构以及单体负载方式对催化活性、选择性和序列长度的影响，并对其机理进行了探讨。从而得到了一种高相对分子质量、顺式-1，4规整度为80 %、ATg=−94 °C的新型乙烯基橡胶材料，即使在其含量高达45 %的情况下，也不会因为聚乙烯短序列而产生明显的熔点。这种新型橡胶材料具有优良的抗流性能和较强的拉伸强度。
Introducing ethylene units into polybutadiene backbones is an approach to synthesize advanced rubber materials, which has been a research challenge because of distinct polymerization mechanisms of the two monomers. To date, onlytrans‐1,4‐ and 1,2‐regulated copolymers have been obtained. Herein, we reported the unprecedentedcis‐1,4 selective copolymerization of ethylene and butadiene by using the thiophene‐fused cyclopentadienyl‐ligated scandium complexes. The effects of the sterics and electronics of the catalytic precursors as well as the monomer loading mode on the activity and selectivity as well as the sequence lengths were investigated, and the mechanism was elucidated. Thus a novel ethylene‐based rubber material possessing a high molecular weight, 80 %cis‐1,4 regularity and aTg=−94 °C without an obvious melting point owing to short polyethylene sequences even at its content up to 45 mol %, was isolated. This new rubber material exhibited excellent anti‐flowing performance and strong tensile strength.