摘要
以多官能度锂(简称Li)为引发剂,在不同条件下合成了3种星形苯乙烯(St)-异戊二烯(Ip)-丁二烯(Bd)三元共聚物,分析了共聚物的结构。结果表明,两次投料法的产物为两嵌段共聚物,低R[四氢呋喃(THF)与Li的摩尔比]值合成的聚异戊二烯(PI)链段的玻璃化转变温度(Tg)为-58.3℃,1,4-结构为83.8%;高R值合成的无规共聚段的Tg为-36.2℃。低R值一次投料法产物为多嵌段共聚物,-69℃为Bd-Ip无规共聚段的Tg,1,4-结构含量高;22.7℃为Ip-St共聚段的Tg,含摩尔分数为6.6%的PS嵌段。高R值一次投料法的产物为三元无规共聚物,1,4-结构含量低,只有1个Tg,为-28.9℃。
Living polymerization provides a lot of synthetic routes to obtain a wide variety of well-defined polymer structures. In general, star shaped polymers can be synthesized by two different ways： ＂ arm-first＂ and ＂core-first＂. In the ＂core-first＂ way, the synthesis of star-shaped polymers can be performed directly in the presence of multifunctional initiators. In this paper, on the basis of a patent technology of multilithium initiator with Sn--C bonds, three new kinds of star-shaped styrene （St） -isopren e （ Ip ） - butadiene （ Bd ） terpolymers （ sample 1,2,3 ） were synthesized by anionic polymerization respectively. All of them have lower number of ＂free end＂ than the star-shaped copolymers coupied by Sn--C bonds through ＂arm-first＂ way.
出处
《合成橡胶工业》
CAS
CSCD
北大核心
2007年第6期474-474,共1页
China Synthetic Rubber Industry
基金
Supported by National Science Foundation of China(50573005).
