聚乙二醇-聚丁二烯-聚乙二醇三嵌段共聚物的制备及性能

Using hydroxyl-terminated polybutadiene (HTPB) obtained by living anionic polymerization and polyethylene glycol (PEG) as raw materials, a polyethylene glycol - polybutadiene - polyethylene glycol (PEG - b - PB - b - PEG) triblock copolymer was prepared successively through benzenesulfonylation and nucleophilic substitution reactions. The infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, carbon nuclear magnetic resonance spectroscopy and gel permeation chromatography - laser light scattering combined instrument were used to confirm that the structure of the obtained triblock copolymer was consistent with the design. The comparative study on the thermal properties of PEG, HTPB and PEG - b - PB - b - PEG by differential scanning calorimetry analysis and thermogravimetric analysis showed that the glass transition temperature (T_g) of PEG - b - PB - b - PEG was -82.8 °C, the crystallization behavior of the PEG segment in its structure was restricted by the amorphous PB segment, and PEG - b - PB - b - PEG had good thermal stability. The research on the assembly characteristics of PEG - b - PB - b - PEG by dynamic light scattering particle size analysis and transmission electron microscope indicated that PEG - b - PB - b - PEG formed stably distributed dot-like micelles in aqueous solution.

以活性阴离子聚合所得端羟基聚丁二烯(HTPB)及聚乙二醇(PEG)为原料,依次通过苯磺酰化和亲核取代反应制备聚乙二醇-聚丁二烯-聚乙二醇(PEG-b-PB-b-PEG)三嵌段共聚物。利用红外光谱、核磁共振氢谱、核磁共振碳谱及凝胶渗透色谱-激光光散射联用仪证实所得三嵌段共聚物结构与设计相一致。差示扫描量热分析及热重分析对PEG、HTPB及PEG-b-PB-b-PEG热性能对比研究显示,PEG-b-PB-b-PEG的玻璃化转变温度(T_g)为-82.8 ℃,其结构中PEG链段的结晶行为被无定形PB链段所限制,且PEG-b-PB-b-PEG具有较好的热稳定性。动态光散射粒度分析及透射电子显微镜对PEG-b-PB-b-PEG组装特性研究表明,PEG-b-PB-b-PEG在水溶液中形成稳定分布的点状胶束。