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以Al(i-Bu)_3(简称Al)为助催化剂,研究了Ti(OC_8H_(17))_(4-n)Cl_n(简称Ti)体系在己烷中合成1,2-聚丁二烯的聚合规律。本体系与Ti(OC_4H_9)_(4-n)Cl_n 体系和Ti(OC_2H_5)_(4-n)Cl_n体系相比,催化活性较高,其转化率分别为 >90、～85和 <80％;与Ti(OC_4H_9)_(4-n)Cl_n体系相比,聚合物分子量较低,[η]分别为5 dL/g和>15dL/g。体系中的氯含量是影响催化活性和聚合物微观结构的主要因素。n值升高,催化活性和1,2-链节含量均降低:n=1,2,3,转化率分别为 73、44和 22％,1,2-链节含量分别为～70、～55和<50％。改变氯含量和聚合温度,可合 1,2-链节含量控制在 40-75％。最佳聚合条件:Al/Ti=25—40(mol比),温度60℃,时间4一6h。在此条件下,聚合物的凝胶含量<15％,且为疏松型。
The synthesis of 1,2-polybutadiene from Ti (OC_8H_ (17)) _ (4-n) Cl_n (referred to as Ti) The polymerization rules. Compared with Ti (OC_4H_9) _ (4-n) Cl_n system and Ti (OC_2H_5) _ (4-n) Cl_n system, the catalytic activity of this system is higher than that of Ti (OC_4H_9) Compared with the Ti (OC_4H_9) _ (4-n) Cl_n system, the molecular weight of the polymer is relatively low, [η] is 5 dL / g and> 15 dL / g, respectively. The chlorine content of the system is a major factor affecting the catalytic activity and the microstructure of the polymer. The value of n increased, the catalytic activity and 1,2-linked content decreased: n = 1, 2 and 3, the conversion rates were 73, 44 and 22% 55 and <50%. Alter the chlorine content and the polymerization temperature, the contents of 1,2-linkages can be controlled at 40-75%. The best polymerization conditions: Al / Ti = 25-40 (mol ratio), temperature 60 ℃, time 4 a 6h. Under these conditions, the polymer gel content <15%, and is loose.