摘要
以同向啮合双螺杆挤出机为反应器,采用正丁基锂为引发剂,以二溴乙烷为偶联剂,用两次加料偶联法成功合成苯乙烯/丁二烯/苯乙烯(SBS)三嵌段热塑性弹性体。核磁共振分析表明共聚物中苯乙烯苯嵌段结构为主,丁二烯单元结构以1,4-加成为主。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前后的聚苯乙烯碎片进行分析证明:共聚物分子为PS-PB-PS的三嵌段结构,共聚物相对分子质量分布较宽。动态力学及透射电镜分析表明SBS具有两相分离结构,但相界面较宽,不同于溶液聚合产物。拉伸试验表明三嵌段结构能显著提高样品力学性能。
Styrene/butadiene/styrene block thermoplastic elastomer（SBS）was polymerized successfully by anionic polymerization using a co-rotating intermeshing twin screw extruder as reactor.The analysis of1 H-NMR shows that the poly-butadiene block of the copolymer is mainly composed of 1,4-butadiene structure.The molecule chain of the copolymers was degraded using hydrogen peroxide catalyzed with osmium tetroxide,the segments of polystyrene after oxidization were characterized by gel permeation chromatographer（GPC）.It is found that the molecular distribution of SBS is wider than that of the solution polymerization product.Cooperated with the survey of dynamic mechanical analysis（DMA）and TEM,it is confirmed that SBS has phase separation structure with wider phase interface.Tensile testing shows that the tensile strength of the copolymer is related to block structure.
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
2015年第10期99-104,共6页
Polymer Materials Science & Engineering
基金
国家自然科学基金重大项目(50390091)
国家自然科学基金重点项目(50933002)
国家863项目(2012AA040306)
关键词
嵌段共聚物
反应挤出
相对分子质量分布
相分离
block copolymer
reactive extrusion
molecular weight distribution
phase separation
