pH敏感性两亲聚合物网络PAA-l-PTHF的研究

pH-Sensitive Poly(acrylic acid)-l- polytetrahydrofuran Amphiphilic Polymer Network

以具有良好柔性和生物相容性的聚四氢呋喃(PTHF)为疏水链段,具有pH敏感性的聚丙烯酸(PAA)为亲水链段,通过PTHF双端基大分子单体与丙烯酸自由基共聚,首次合成了聚丙烯酸-l-聚四氢呋喃(PAA-l-PTHF)两亲聚合物网络,并对网络的结构、组成以及交联点密度进行了表征。两亲聚合物网络溶胀行为研究表明,PAA-l-PTHF既能在水中溶胀又能在有机溶剂中溶胀,在水中的溶胀度随网络亲水链段PAA含量的增加而增加,在有机溶剂中的溶胀度随网络疏水链段PTHF含量的增加而增加。溶胀结果进一步表明两亲聚合物网络除了具备亲水、疏水链段各自的特征外还存在两种链段相互影响产生的特殊溶胀行为,说明亲、疏水链段在网络中分别聚集形成微相分离的相态结构。研究结果还表明,PAA-l-PTHF两亲网络具有较为明显的pH敏感性和温度敏感性。

A series of novel poly(acrylic acid) l polytetrahydrofuran (PAA l PTHF) amphiphilic networks were synthesized by free radical copolymerization of hydrophobic polytetrahydrofuran diacrylate macromonomer with hydrophilic acrylic acid. Their structure and composition have been characterized and the swelling behaviors of these networks were studied. The amphiphilic nature of them is substantiated by swelling data. They swell in both hydrophilic and hydrophobic solvents and the swelling ratio changes significantly with network composition, which increased with increasing of hydrophilic content of networks in water. The swelling behavior of networks in different solvents exhibits not only the properties of both hydrophilic and hydrophobic segments, but also the combined properties of the two segments. These amphiphilic networks exhibit different swelling process in hydrophilic solvents and hydrophobic solvents, and show pH sensitive swelling in aqueous media.