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本文研究了丁二烯-异戊二烯在氯化稀土-醇-三烷基铝催化体系中共聚合的规律。从聚合物的玻璃化温度和热裂解色谱证明了聚合产物确系共聚物。共聚速率方程可表示为:R_p=K_p[M]~2[cat]。测定了丁二烯与异戊二烯在Ⅲ-B族钪、钇和镧系元素在不同溶剂催化体系中的共聚速率常数、表观活化能及竞聚率。各种体系中都得到r1_(丁二烯)>1,r2_(异戊二烯)<1,r1·r2接近于1的结果。用统计方法对共聚物的序列分布作了讨论,证明共聚物中同种单体两单元以下连结的链节约占60—70％,说明生成的是无规共聚物。共聚物的组成和结构随条件变化而变化的范围不大,其中丁二烯与异成二烯链节的顺-1,4含量,一般都在95％以上。
In this paper, the law of butadiene-isoprene copolymerization in the rare earth-alcohol-trialkylaluminum chloride system was studied. From the glass transition temperature of the polymer and the pyrolysis chromatogram proved that the polymerization product is indeed a copolymer. The copolymerization rate equation can be expressed as: R_p = K_p [M] ~ 2 [cat]. The copolymerization rate constants, apparent activation energy and reactivity ratio of butadiene and isoprene in Ⅲ-B scandium, yttrium and lanthanides in different solvent catalysis systems were determined. In all systems, r1_ (butadiene)> 1, r2_ (isoprene) <1 and r1 · r2 near 1 were obtained. The statistical distribution of the copolymers was discussed. It was demonstrated that the chain linkages between two units of the same type of monomers in the copolymer accounted for 60-70% of the total, indicating that random copolymer was formed. Copolymer composition and structure changes with the conditions vary little range, butadiene and isoprene link cis-1,4 content, are generally more than 95%.