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研究了异戊二烯在希土催化剂中的聚合,结果证明,异戊二烯可在由希土化合物-三烷基铝-卤化物组成的催化体系中聚合生成顺式-1,4链节含量达95％、分子量高至10~6的聚合物,催化活性与希土金属、三烷基铝、卤化物及希土化合物中取代基的性质有关,但聚合物的链节结构与上述某些因素关系不大。通过对催化体系中希土价态的分析及对卤化物在聚合中作用的研究,提出活性催化剂可能是含有希土烷基化合物的双金属络合物的假设。
The polymerization of isoprene in a rare earth catalyst was studied. As a result, it was proved that isoprene can be polymerized in a catalytic system composed of a rare earth compound-trialkylaluminum-halide to produce a cis-1,4 chain segment content Up to 95% and molecular weight up to 10 ~ 6, the catalytic activity is related to the properties of the substituents in the rare earth metals, trialkylaluminums, halides and rare earth compounds, but the structure of the polymer chain links with some of the above Little relationship between factors. Through the analysis of the valence state of the rare earth in the catalytic system and the research on the role of the halide in the polymerization, it is proposed that the active catalyst may be the bimetallic complex containing the rare earth alkyl compound.