多臂星形聚乙烯亚胺的设计合成及聚合动力学

Design,Synthesis and Polymerization Kinetics of Star-Like Polyethylenimine

非病毒基因载体聚乙烯亚胺结构不可控,同时最优结构未知,因此文中采用Core-First的方法,以三氟甲磺酸酯作为引发剂,通过2-乙基-2-恶唑啉阳离子开环聚合合成了二臂、四臂、六臂和八臂星形聚乙烯亚胺。利用核磁共振氢谱、凝胶渗透色谱仪对合成的星形聚合物的结构、相对分子质量及其分布进行了表征,并对2-乙基-2-恶唑啉的开环聚合动力学进行了研究。结果表明,合成得到了结构明确、窄分散的多臂星形聚乙烯亚胺,且该聚合反应符合活性聚合的特征。

A novel star-like non-viral gene carrier polyethylenimine was prepared via living cationic ring-opening polymerization of 2-ethyl-2-oxazoline initiated by trifluoromethylsulfonate. The molecular structure of the resulting polymer was confirmed by 1H nuclear magnetic resonance spectroscopy （NMR）. The molar masses and polydispersity of synthesized polymer were characterized by gel permeation chromatography. Polymerization kinetics results indicate that the apparent polymerization rate increases linearly with the number of initiating groups per molecule and the initiating groups of initiators E- H are of equal reactivity for the polymerization initiation of 2-ethyl-2-oxazoline. Thus all initiators are of the same reactivity and all arms grow at the same rate. This method leads to polymers with controlled molecular weights and narrow molecular weight distributions.