Metals from Groups I and II and organometallic compounds thereof can be used to catalyze the polymerization of diene monomers into polymers. The polymers formed in such polymerizations are terminated with the metal used to catalyze the polymerization and are sometimes referred to as living polymers. Very useful blends of such polymers can be made by utilizing the process of the present invention. More specifically, the present invention discloses a process for preparing a polydiene rubber blend comprising: (1) polymerizing at least one diene monomer utilizing at least one catalyst selected from the group consisting of Group I metals, Group II metals, organometallic compounds containing a Group I metal, and organometallic compounds containing a Group II metal, to a conversion which is within the range of 30% to 70% to produce low molecular weight polydiene chains; (2) joining from 20% to 70% of said low molecular weight polydiene chains with a suitable branching agent; and (3) allowing the polymerization to continue so as to produce said polydiene rubber blends.
I 族和 II 族
金属及其有机
金属化合物可用于催化二烯单体聚合成聚合物。在这种聚合反应中形成的聚合物以用于催化聚合反应的
金属为末端,有时被称为活聚合物。利用本发明的工艺可以制造出非常有用的此类聚合物混合物。更具体地说,本发明公开了一种制备聚二稀橡胶混合物的工艺,包括(1)利用选自第一类
金属、第二类
金属、含第一类
金属的有机
金属化合物和含第二类
金属的有机
金属化合物的至少一种催化剂,使至少一种二烯单体聚合,其转化率在30%至70%范围内,以产生低分子量的聚二烯链;(2)用合适的支化剂连接20%至70%的所述低分子量聚二烯链;以及(3)使聚合继续进行,以产生所述聚二烯橡胶混合物。