PSf-b-PEG嵌段共聚物的合成与结构调控

Synthesis and structure regulation of PSf-b-PEG block copolymer

通过一锅法亲核取代共缩聚反应合成系列聚砜-b-聚乙二醇嵌段共聚物。首先研究聚砜的合成动力学,揭示双酚A和4,4′-二氯二苯砜的投料比与聚合时间对聚砜分子量的影响规律。其次,在聚砜聚合反应9 h时,选用不同链段长度的聚乙二醇作为封端剂,合成系列聚砜-b-聚乙二醇嵌段共聚物。采用核磁共振氢谱(^(1)H NMR)、凝胶渗透色谱(GPC)、热重分析(TGA)、差式扫描量热(DSC)表征聚砜-b-聚乙二醇的分子结构与热稳定性能。结果表明,当采用分子量分别为400、2000、6000 Da的聚乙二醇封端剂时,所制得的聚砜-b-聚乙二醇嵌段共聚物分子量分别为3.9×10^(4)、3.9×10^(4)、4.4×10^(4) Da,PEG含量从1.3%(质量分数)增加到12.8%,其玻璃化转变温度从170.7℃降低到117.1℃。

A series of PSf-b-PEG block copolymers with different PEG contents are synthesized through the one-pot step-growth polymerization.Firstly,the polymerization kinetics of PSf is investigated by changing the feed ratio of bisphenol A and 4,4′-dichlorodiphenyl sulfone,and the polymerization time.Subsequently,PSf-b-PEG block copolymers are synthesized using different length of PEGs as capping reagents.The molecular structure and thermal stability of PSf-b-PEGs are analyzed by ^(1)H NMR,GPC,TGA and DSC.Results show that the number average molecular weights of PSf-b-PEG are 3.9×10^(4),3.9×10^(4),4.4×10^(4) Da,upon the addition of end-capping reagent(PEG)having the molecular weight of 400,2000,and 6000 Da,respectively.As the molecular weight of PEG increases,the PEG content of PSf-b-PEG increases from 1.3 wt%to 12.8 wt%,and the glass transition temperature of PSf-b-PEG decreases from 170.7℃to 117.1℃.