以氯代烃为第三组分的稀土定向聚合催化剂——Ⅱ.顺丁橡胶的结构与性能

RARE EARTH STEREOSPECIFIC POLYMERIZATION CATALYST WITH ORGANIC CHLORIDES AS THIRD COMPONENT Ⅱ.RELATIONSHIP BETWEEN STRUCTURE AND PROPERTIES OF cis-POLYBUTADIENE

研究了Nd(naph)_3-Al(i-Bu)_2H-t-BuCl(或allyl-Cl)催化体系制得的顺丁橡胶(BR)的结构与性能。结果表明,[η]=2.7～3.7dL/g,分子量分散指数小于4,[η]<1低分子级分含量小于50％,顺式-1,4含量大于或等于95％时,其生胶、混炼胶和硫化胶的性能均良好,硫化胶的综合性能与一般稀土体系BR和镍系BR相当甚至超过。

Two types of cis-polybutadiene rubbers (BR) were prepared by using two novel homogeneous rare earth catalyst systems Nd(naph)-Al(i-Bu)2H-t-BuCl or -allyl-Cl, with hexane as solvent in a 1 L polymerization reactor .The ef fects of intrinsic viscosity [η] , molecular weight distribution (D) and cis -1,4 content of BR on the properties of raw rubber , compounds and vulcanizates were investigated. The results showed that when [η] was in the range of 2.7 to3.7 dL/g , D<4 ,low molecular weight fraction ([η]<1) was less than 50% and cis -1,4 content more than 95% , these two BRs had better mechanical properties as compared with the BRs prepared by nickel catalyst system or general rare earth catalyst system .