反应挤出法合成S/B多嵌段共聚物的研究

在阴离子引发体系下 ,以双螺杆挤出机为反应器 ,采用丁二烯、苯乙烯混和单体加料方式 ,本体法一步合成了S B多嵌段共聚物 .考察了螺杆转速、进料速率以及不同丁苯配比对反应挤出合成PS及S B嵌段共聚物聚合转化率的影响 .用1 H NMR、IR、DMA、TEM等方法对S B嵌段共聚物进行了表征 ,结果表明共聚物由多个微小的丁二烯嵌段和少量无规段组成 .当丁二烯含量少至 15 %左右时 ,其嵌段可回缩成球状 ,粒径大约在 30～ 5 0nm .该材料的韧性随着共聚物中丁二烯含量的增加而逐渐提高 ,特别是断裂延伸率的提高尤为显著

STUDIES ON S/B MULTI-BLOCK COPOLYMER POLYMERIZED BY REACTIVE EXTRUSION

A kind of styrene|butadiene (S/B) multi|block copolymer was bulk|polymerized in a twin|screw extruder with the anion initiators and mixed S/B monomers. The effects of screw rotational speed,feed rate of monomers and St content on the conversion of styrene and S/B mixture were researched.S/B block copolymer was characterized by 1H NMR, IR,DMA.It is shown that a lot of short polybutadiene blocks and a little random structure coexist in the copolymer. It also can be seen in TEM photographs that the polybutadiene blocks, while being less than 15% in whole composition, can retract into the ball shape 30～50?nm in diameter. On the other hand, the toughness, especially the elongation at break, of the copolymer grows stronger with the increase of butadiene content.