聚丁二烯-聚四氢呋喃三嵌段共聚物的合成与热性能

Synthesis and Thermal Properties of Poly(Tetrahydrofuran)-Poly(Butadiene)-Poly(Tetrahydrofuran) Triblock Copolymer

以端羟基聚丁二烯(HTPB)为引发剂,在三氟化硼乙醚(BF3·OEt2)的催化作用下,利用四氢呋喃(THF)的阳离子开环聚合制备PTHF-PB-PTHF三嵌段共聚物。利用红外光谱、核磁氢谱、碳谱及凝胶渗透色谱-激光光散射联用仪证实了其大分子结构与分子设计一致且相对分子质量可控。聚合工艺研究表明,催化剂用量对聚合反应的影响较小,嵌段共聚物相对分子质量随单体与引发剂配比的增大而提高。利用热重分析仪及差示扫描热分析研究了聚合产物的热稳定性及低温玻璃化转变行为,结果表明,产物具有较好的热稳定性,其玻璃化转变温度可达-80℃以下。

Poly(tetrahydrofuran)-poly(butadiene)-poly(tetrahydrofuran) triblock copolymer was synthesized by cationic ring-opening polymerization of tetrahydrofuran in the presence of hydroxyl-terminated polybutadiene as macroinitiator and boron trifluoride etherate as catalyst. The results of FT-IR,1H-NMR,13C-NMR and size exclusion chromatography/multi-angle laser light scattering(SEC) reveal that the chemical structure of resulting copolymers is consistent with design and the molecular weight can be controlled. Study of the polymerization process represents the minor impact of catalyst on the polymerization reaction,and shows that the molecular weight of the copolymers increases with increase of the monomer to initiator ratio. TGA and DSC was used to study the thermal stability and glass transition temperature of the products. The results suggest that the products exhibit excellent thermal stability,and the glass transition temperature can be lower than-80 ℃.