【摘要】 <正> 稀土络合催化体系用于丁二烯-异戊二烯的定向聚合研究在我国已取得了显著成绩,但有关分子量测试工作却很少研究。关于该催化体系合成的高顺式1,4-丁二烯-异戊二烯嵌段共聚物的分子量表征工作未见报道。本文采用GPC和[η]测定方法表征了丁二烯-异戊二烯嵌段共聚物的分子量。更多还原

【Abstract】 Rare-earth metal complex catalysts have been used in stereospecific polymerizations of butadiene and isoprene, and a great progress has been obtained in our country. However, there are only a few papers which are dealing with molecular weight measurements of the resulting polymers and no report concerning molecular weight characterization of high cis-1, 4-butadiene-isoprene block copolymers prepared with this catalyst system is available.This paper involves fractionation of polybutadiene and polyisoprene homopolymers synthesized with this calallyst by fractional precipitation, GPC and [η] measurements of these samples with narrow distribution and some others with broad distribution, and establishment of the Mark-Houwink equations for cis-1, 4-polybutadiene and cis-1, 4-polyisoprene and, in turn, of the composition-dependent Mark-Hou-wink equation for butadiene-isoprene block copolymers.更多还原