摘要
用NdCl_3nTBP/Mgcl_2—Al(i-Bu)_2体系催化合成聚异戊二烯,研究了催化剂制备条件对聚合的影响。结果表明,催化剂加少量单体陈化,催化活性明显提高。当I_P/Nd=100时,Nd/I_p=2×10^(-5),转化率可达96％,值化效率为2.3×10~4g胶/gNd,提高陈化浓度可降低催化剂用量,向I_p—Al—Nd三元陈化体系中加第四组份—Al_2(i—Bu)_2Cl_2,则催化活性明显提高,分子量降低。本体系提高陈化温度对聚合产物的微观结构无影响,而使分子量分布变窄。随聚合温度的提高,产物的cia—1,4结构含量降低,分子量分布基本不变。
Effect of preparation condition on the polymerization of isoprene was studied with NdCl_3nTBP/Al(i—Bu)_3catalystic system. This study indicated :the catalystic activity of the catalyst with a little isoprene was markedly increased; when the Nd/Ip molar ratio was only 2×10^(-5) at Ip/Nd= 100 the conrersion of 96% and the catalystic efficiency of 2.3×10~4Gp/gNd were obtained; the amount of catalyst was reduced as the prptaration concentration was high; with the third component added to the system, the catalytic activity was increased and the molecular weight decreased, the microstructure of polyisoprene was unchangeable, the molecular weight distribution became narrower at a high preparation temperature, but the content of cis—1,4—chain unit of polyisoprene was disreased and the molecular weight distribution was not changed when the polymerization temperature arose.
出处
《弹性体》
CAS
1992年第2期28-32,共5页
China Elastomerics
