摘要
以n-BuLi/TMEDA(四甲基乙二胺)为金属化试剂,环己烷为溶剂,研究了1,2-结构和1,4-结构分别为98％和92％的聚丁二烯(PB)在70℃时的锂化反应动力学。结果表明,PB的初始锂化反应速度与[n-BuLi]和[PB]的一次幂成正比:对高1,2-结构PB,K_p=(αk_(0.5)+βk_1)×[PB][n-BuLi],k_(0.5)/k_1=0.78,反应活化能为54.0 kJ/mol;当两种结构PB存在,[TMEDA]/[n-BuLi]_0>1时,K_p(ak_(1.2)+b_(1.4))[PB][n-BuLi];1,4-结构PB的锂化反应活性高于1,2-结构PB。
The kinetics of lithiation for polybutadiene (PB) with 1,2-and 1,4-units contents of 98% and 92% , respectively, was investigated at 70°C , by using n-BuLi/TMEDA (tetramethylethanediamine) as metallizing reagent and cyclohexane as solvent . The results showed that the initial rate of lithiation of PB was proportional to the first order of [n-BuLi] and [PB] . For high 1,2-polybutadiene , Kp= ( α0.5+βk1) [PB][n-BuLi] , k0.5/k1 = 0.78 ,and reaction activation energy was 54.0 kJ/mol . When both 1,2-and 1,4-units existed in PB ,and [TMEDA]/[n -BuLi]0> 1, Kp= (αk1,2+bk1,4)[PB][n-BuLi] .The lithiation reactivity of 1,4-polybutadiene was higher than that of 1,2-polybutadiene .
出处
《合成橡胶工业》
CAS
CSCD
北大核心
1990年第6期406-409,共4页
China Synthetic Rubber Industry
基金
中国科学院自然科学基金
关键词
聚丁二烯
锂化反应
反应动力学
lithiation
reaction kinetics
high cis- 1,2- polybutadiene
high cis-1,4 - polybutadiene
n -butyllithium
tetramethylethanediamine
