中文摘要：

以同向啮合双螺杆挤出机为反应器,采用苯乙烯和异戊二烯为聚合单体,以正丁基锂为引发剂,采用三次加料法合成苯乙烯/异戊二烯/苯乙烯（SIS）三嵌段热塑性弹性体。氢核磁共振（1H NMR）谱分析结果表明,共聚物中聚异戊二烯嵌段以1,4-结构为主。采用四氧化锇催化双氧水氧化降解聚合物分子链,利用凝胶渗透色谱对氧化降解后的聚苯乙烯碎片进行分析,证明共聚物分子为（聚苯乙烯-聚异戊二烯-聚苯乙烯）（ PS-PI-PS）三嵌段结构。动态力学分析（ DMA）及透射电子显微镜（ TEM）分析结果表明, SIS具有两相分离结构。拉伸试验结果表明,共聚物拉伸强度与苯乙烯含量有关。

英文摘要：

Styrene/isoprene/styrene （ SIS ） triblock thermoplastic elastomer was polymerized by three times feeding method using a co-rotating intermeshing twin screw extruder as the reactor and n-butyllithium as the initiator. 1 H NMR spectra show that the polyisoprene block of the copolymer is mainly composed of 1,4-polyi-soprene structure. The molecule chains of the copolymers were degraded using hydrogen peroxide catalyzed by osmium tetroxide, the segments of polystyrene after oxidization were characterized by gel permeation chroma-tography（ GPC） cooperating with the multi-angle laser light scattering（ MALLS） instrument. It was found that the copolymers consisted of polystyrene-polyisoprene-polystyrene（ PS-PI-PS） three blocks. Cooperated with the survey of dynamic mechanical analysis（DMA） and transmission electron microscope（TEM） photographs, it was confirmed that styrene/isoprene/styrene（ SIS） had two phase separation structure. Tensile testing showed the relationship between tensile strength of the copolymer with styrene content.