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本文用动力学方法测定了Ti(n-C_4H_9O)_(4-x)Cl_x—Al(i-C_4H_9)_3体系,当x不同时,在己烷中催化丁二烯聚合的催化剂利用率、增长速率常数、增长活化能等参数。测得催化剂利用率都只有1％左右,其聚合速率差别主要因kp不同引起。同时,测定了体系中各组分的链转移常数,发现该体系随x值不同有着很不相同的链转移规律。对于Ti(n—C_4H_9O)_4体系,增长链主要是向烷基铝转移,且呈二级反应;而Ti(n—C_4H_9O)_2Cl_2主要发生主催化剂自身转移。链转移强度的不同,决定着所得聚合物的最大分子量。
In this paper, Ti (n-C_4H_9O) _ (4-x) Cl_x-Al (i-C_4H_9) _3 system was determined by kinetic method. The catalytic activity of catalyst for butadiene polymerization in hexane was increased when x was different Rate constant, growth activation energy and other parameters. Measured catalyst utilization rate of only about 1%, the polymerization rate difference due to different kp caused. At the same time, the chain transfer constants of each component in the system were determined. It was found that the system had very different chain transfer rules with different x values. For Ti (n-C_4H_9O) _4 system, the growth chain is mainly transferred to the aluminum alkyl, and the secondary reaction; and Ti (n-C_4H_9O) _2Cl_2 the main catalyst self-transfer occurs. The difference in chain transfer strength determines the maximum molecular weight of the resulting polymer.