Stimuli-Responsive Diblock Copolymers by Living Cationic Polymerization: Precision Synthesis and Highly Sensitive Physical Gelation
Stimuli-Responsive Diblock Copolymers by Living Cationic Polymerization: Precision Synthesis and Highly Sensitive Physical Gelation
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DOI：
10.1021/ma035037t
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发表时间：
2004
期刊：
影响因子：
5.5
通讯作者：
S. Sugihara;K. Hashimoto;S. Okabe;M. Shibayama;S. Kanaoka;S. Aoshima
中科院分区：
文献类型：
--
作者：
S. Sugihara;K. Hashimoto;S. Okabe;M. Shibayama;S. Kanaoka;S. Aoshima
通过连续活性阳离子共聚反应合成了具有热敏性链段和亲水性链段的刺激响应性二嵌段共聚物，该共聚反应包括具有在水中表现出LCST型相分离的氧杂环侧基的聚（乙烯基醚）和聚（羟乙基乙烯基醚）链段。高灵敏度和可逆的热诱导胶束的形成和/或物理凝胶化观察与这样的二嵌段共聚物。例如，二嵌段共聚物的水溶液的流动行为在非常窄的温度范围内从牛顿流动变为非牛顿流动和塑性流动。TEM和SANS研究表明，所观察到的粘度的变化是由于在水溶液中的球形胶束的体心立方对称的大晶格的形成。胶束形成和/或物理凝胶化的临界温度可以通过改变二嵌段共聚物中两个链段的组合来改变。在此基础上，一些系统...
Stimuli-responsive diblock copolymers with a thermosensitive segment and a hydrophilic segment have been synthesized via sequential living cationic copolymerization, which involves a poly(vinyl ether) with oxyethylene pendants exhibiting LCST-type phase separation in water and a poly(hydroxyethyl vinyl ether) segment. Highly sensitive and reversible thermally induced micelle formation and/or physical gelation were observed with such diblock copolymers. For example, the flow behavior of an aqueous solution of a diblock copolymer varied from Newtonian to non-Newtonian and plastic flow within a very narrow temperature range. TEM and SANS studies showed that the observed change in viscosity was due to the formation of a macrolattice with body-centered-cubic symmetry of spherical micelles in aqueous solution. The critical temperature of micelle formation and/or physical gelation could be varied by altering the combination of two segments in the diblock copolymer. On the basis of these results, several systems ...