Synthesis and Aggregation Behaviors of Nonlinear Multiresponsive, Multihydrophilic Block Copolymers

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• 作者：Weidong Zhang ; Wei Zhang ; Zhenping Cheng ; Nianchen Zhou ; Jian Zhu ; Zhengbiao Zhang ; Gaojian Chen ; Xiulin Zhu
• 刊名：Macromolecules
• 出版年：2011
• 出版时间：May 10, 2011
• 年：2011
• 卷：44
• 期：9
• 页码：3366-3373
• 全文大小：939K
• 年卷期：v.44,no.9(May 10, 2011)
• ISSN：1520-5835

文摘

The well-defined nonlinear multiresponsive, multihydrophilic block copolymers (MHBCs), poly(N-isopropylacrylamide)₂鈭抂poly(N-vinylpyrrolidone)-b-poly(acrylic acid)]₂ ((PNIPAAM)₂(PNVP-b-PAA)₂) and poly[N-isopropylacrylamide-b-(acrylic acid)]₂鈭抪oly(N-vinylpyrrolidone)₂ ((PNIPAAM-b-PAA)₂(PNVP)₂), were successfully synthesized via a combination of single-electron transfer living radical polymerization (SET-LRP) and reversible addition鈭抐ragmentation chain transfer (RAFT) polymerization techniques. All the final miktoarm star block copolymers were characterized by GPC and ¹H NMR spectra. Interestingly, the hydrogen bonding interactions have a great effect on the water solubility of PAA chains, and the nonlinear MHBCs solutions showed sharp phase separation at pH = 7.0. The novel water-soluble nonlinear MHBCs consisting of pH-responsive PAA segments, thermoresponsive PNIPAAM segments, and hydrophilic, noncharged and biocompatible PNVP segments tend to self-assemble into three different types of micellar aggregates and umimers, which can be reversibly controlled by pH value and temperature of aqueous solution of these copolymers.