【摘要】 本文以叔丁氧基钾-正丁基锂作引发剂,甲苯作溶剂,在无极性添加剂及添加极性试剂二种情况下,研究了丁二烯阴离子聚合反应速率若干因素。在K/Li=1.1,A/Li=0,温度为0℃情况下,引发剂浓度与聚合反应速率R_p呈一级关系,表观增长速率常数k_ap不随引发剂浓度的增大而改变;在K/Li=0.5和1.1,A/Li=0,k′=2/100条件下,k_ap相差较大,但表观增长活化能E_ap均为45.2kJ/mol;K/Li<1.0时,Rp随K/Li增加不断增加,K/Li>1.0后,Rp逐步趋向不变。体系中添加极性给电子试剂,能够极大地提高聚合反应速率。更多还原

【Abstract】 This paper reports the kinetic study of butadiene polymerization in toluene with n-butyl lithium and potassium butoxide as catalyst and with or without the addition of polar modifiers. It is found that,when K/Li=0,at 0℃, the reaction order of initiator concentration with respect to polymerization rate was 1; apparent rate constant k_a_p of polymerization was independent of the initiator concentration. When K/Li=0.5 and 1.1, A/Li=0, k′=2/100, k_a_p differed significantly, but the apparent energy of activation E_a_p in both cases gave the same value:45.2kJ/mol. When K/Li<1.0, the polymerization rate increased with increase of K/Li; when K/Li>1.0, the polymerization rate became constant. Addition of polar modifiers greatly increased the rate of polymerization.更多还原