摘要
根据不同有机卤基团和硝基苯-吡啶的特征性性反应原理,区别澳端基液体聚丁二烯中的两种溴基,并计算出烯丙基溴含量。用VPO法测定(?)_n,计算误差<±5％。用本法计算的数均官能度与实测相符;该法可以推广用于其他类似结构的有机卤化物的测定。
Dibromopolybutadiene (DBBD) liquid rubber was synthesized from butadiene by emulsion polymerization in the presence of carbon tetrabromide as chain transfer agent.When the usage of CBr4,emulsifier S and initiator P were 20%,5% and 3.5%-4.5%, respectively, polymerization temperature was 60-75℃ and reaction time was within 18-24 h, the polymerization conversion could reach over 90%.The polymer obtained was characterized by infrared absorption spectrometry, VPO and chemical analysis, and the average functionality calculated was approximately 2. The molecule structure of DBBD was represented by the following formula:Br ( Bd ) nCBr2 ( Bd ) mCBr2 ( Bd )n' Br, where m >> n.It was found that the dosage of CBr4 had an important effect on the conversion of polymerization and the average molecular weight of polymer obtained, and when its usage was increased from 15% to 40%, the number average molecular weight of the polymer obtained decreases from 7800 to 4 200.Thus, it was possible to control the viscosity of DBBD to meet the specific requirements.
出处
《合成橡胶工业》
CAS
CSCD
北大核心
1990年第2期126-127,共2页
China Synthetic Rubber Industry
关键词
溴端基
聚丁二烯
官能度
测定
butadiene
emulsion polymerization
liquid polybutadiene
dibromopolybutadiene
carbon tetrabromide
