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异戊二烯(Ip)在甲苯、环己烷及己烷中用VCl_3-Ti(OR)_4-Al(i-Bu)_3为催化剂均能聚合成反式-1,4-聚异戊二烯(TPI)。催化剂呈非均相,聚合有明显的诱导期。TPI的[η]与单体、烷基铝和钛化合物的浓度以及聚合温度和转化率均无关。当聚合在2—5公斤/厘米~2氢压下进行时,能显著降低聚合体系的粘度,但氢在本体系中不是有效的分子量调节剂。Ip中环戊二烯的含量≤20 ppm时对聚合无影响。
Isoprene (Ip) can be polymerized to trans-1,4-polyisoprene in toluene, cyclohexane and hexane using VCl_3-Ti (OR) _4-Al Ene (TPI). The catalyst was heterogeneous, polymerization had a clear induction period. The [η] of the TPI is independent of the monomer, the concentration of the aluminum alkyl and the titanium compound, and the polymerization temperature and the conversion. When the polymerization is carried out at a hydrogen pressure of 2 to 5 kg / cm 2, the viscosity of the polymerization system can be significantly reduced, but hydrogen is not an effective molecular weight regulator in the present system. The content of cyclopentadiene in Ip ≤20 ppm had no effect on the polymerization.