【摘要】 先用五甲基茂基三苄氧基钛 /甲基铝氧烷催化苯乙烯预聚 ,再与丁二烯进行嵌段共聚合。考察预聚时间、催化剂浓度、苯乙烯浓度等条件对嵌段共聚合反应的影响。共聚产物经沸丁酮、沸甲苯、沸四氢呋喃、沸氯仿连续抽提后 ,嵌段共聚物主要存在于氯仿的可溶级分中。随着预聚时间的增加 ,共聚反应催化效率增加 ,共聚产物中丁二烯含量下降 ;随着催化剂浓度增加 ,共聚催化效率增加 ,[Ti]为 2 .0× 1 0 -4 mol/L时 ,共聚活性达到最大值 ( 1 7.78× 1 0 3 gP/gTi) ,随着催化剂浓度进一步增加 ,共聚催化效率下降 ,共聚产物中丁二烯含量变化亦存在峰值。更多还原

【Abstract】 Because butadiene was more reactive than styrene, we designed a new block copolymerization route of styrene/butadiene. Styrene was first prepolymerized and then butadiene was introduced into glass flask. The block copolymerization of styrene/ butadiene was carried out by using a novel catalytic system of (5 pentamethyl cyclopentadienyltribenzyloxy titanium[Cp*Ti(OBz) 3] and methylaluminoxane(MAO). The optimum copolymerization conditions, including time(pre), styrene concentration and Cp*Ti(OBz) 3 concentration ([Ti]) were investigated. The copolymerization products were fractionated by successive solvents extraction with boiling butanone, toluene, THF and chloroform. The block copolymers chiefly exsisted in chloroform soluble fractions. With time(pre) increasing, copolymerization catalytic efficiency increased and chloroform soluble fractions reduced. With [Ti] increasing, copolymerization catalytic efficiency and chloroform soluble fractions chloroform soluble fractions had a maximum. When [Ti] was 2.0×10 -4 mol/L, copolymerization catalytic efficiency became maximum (17.78×10 3 gP/gTi).更多还原