丁苯橡胶的阳离子环化

Cationic Cyclization of Styrene Butadiene Rubber

应用一氯二乙基铝和苄基氯催化剂体系进行了丁苯橡胶的阳离子环化反应。研究了反应温度、苄基氯／ 一氯二乙基铝比例、溶剂、原胶浓度对环化的影响。发现通过控制苄基氯／ 一氯二乙基铝比，可在高温（１２０ ℃） 、高原胶浓度（２ ～４ ％ ｗ／ｖ） 下进行丁苯橡胶的环化，制得特性粘度较原胶有大幅度降低，可溶性无凝胶的环化丁苯胶。通过对红外光谱、１ Ｈ－ ＮＭＲ 谱的初步解析，证实了环化反应的发生。

Styrene butadiene rubber (SBR) was cyclized with the aid of cationic catalyst system based on diethylaluminum chloride(Al) and benzyl chloride(RCl). The effects of temperature, RCl/Al molar ratio, solvent and concentration of SBR were investigated. By the control of RCl/Al molar ratio,gel free Cyclized SBR with low intrinsic viscosity and ready solubility was obtained in the condition of high temperature(120 ℃) and high concentration of SBR[2～4% (w/v)]. The occurrence of SBR cyclization was confirmed by the primary analysis of IR and 1 H-NMR spectra.