摘要
比较了几种庞钛化合物／甲基铝氧烷／三甲基铝均相催化剂的苯乙烯间规聚合，认为茂基三正丙氧基钛[CpTi（O－n－Pr）3]是苯乙烯间规聚合的良好催化剂[催化效率：ωPs·ωTi-1=4×104g·g-1]．探索了催化剂浓度、单体浓度、聚合温度和时间对苯乙烯聚合的影响．聚合反应产物用佛丁酮萃取，沸丁酮不可溶级分大于95％，经13CNMR分析该级分为间规聚苯乙烯．
Syndiotactic polystyrene was synthesised with metallocene catalysts activated bymethylaluminoxane(MAO) and trimethylaluminum (TMA ). The catalytic efficlency (C. E. )for syndiospecific styrene polymerization was compared with different η5-cyclopentadi-enyltrialkoxy titanium [CpTi (OR)3]. η5-Cyclopentadienyltripropoxy titanium [CpTi (O-n-Pr)3]/MAO/TMA catalyst has a exceedingly high value of C. E. = 4 × 104 g PS. (g Ti)-1.The catalytic efficiency of the catalyst and the molecular weight and syndiospecificity ofpolystyrene were affected by catalyst composition and concentration, monomer concentra-tion, polymerization temperature and time. The optlum conditions of polymerization ofstyrene for [CpTi(O-n-Pr)3]/MAO/TMA catalyst are Al/Ti (molar ratio) = 1000, tempera-ture about 60 C, high styrene concentration (>2. 4 mol/L) and c(Ti) = 0. 14 mmol/L formaximum activity or c(Ti) = O. 18 mmol/L for maximum yield- The sPS was separated frompolymerization product by extraction with boiling butanone for 8 h, the yield of sPS over95 %.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
1997年第12期2065-2069,共5页
Chemical Journal of Chinese Universities
基金
国家自然科学基金
广东省自然科学基金
关键词
聚苯乙烯
苯乙烯
间规聚合
茂金属
催化剂
茂钛
Syndiotactic polystyrene, Methylaluminoxane, Syndiospecific polymerization ofstyrene, Metallocene catalyst
