Facile Synthesis of Macroporous Cross-Linked Methacrylate Gels by Atom Transfer Radical Polymerization
Facile Synthesis of Macroporous Cross-Linked Methacrylate Gels by Atom Transfer Radical Polymerization
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DOI：
10.1021/ma800563p
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发表时间：
2008-10-14
期刊：
影响因子：
5.5
通讯作者：
Hanada, Tefichi
中科院分区：
文献类型：
--
作者：
Kanamori, Kazuyoshi;Hasegawa, Joji;Hanada, Tefichi
以1，3-丙三醇二甲基丙烯酸酯(GDMA)为原料，采用原子转移自由基聚合(ATRP)方法合成了具有良好双连续结构的大孔交联型有机聚合物整体。加入适量的聚环氧乙烷(PEO)后，GDMA在聚合过程中发生了调幅分解。ATRP的均匀凝胶固化了旋节分解的时间两相形态，导致干燥后形成定义良好的大孔凝胶。以这种方式获得的大孔干凝胶包括相互连接的骨架和大孔，这是旋节分解的特征。通过改变起始组成简单地控制了大孔的大小和体积。红外光谱分析和热分析表明，聚乙二醇单甲醚分散在富GDMA相中的量是不容忽视的。自由基聚合通常用于合成多孔聚合物凝胶，通常会导致非均相交联形成局部微凝胶，并阻碍交联体系在延伸长度范围内发生调幅分解。另一方面，活性聚合允许均匀的交联，因此在PEO的共聚中诱导了各向同性的调幅分解。这种简便的合成方法将使交联型有机聚合物凝胶的孔道性质得到更精确的控制。
Macroporous cross-linked organic polymer monoliths with well-defined bicontinuous structure have been synthesized from 1,3-glycerol dimethacrylate (GDMA) in a solvent utilizing atom transfer radical polymerization (ATRP). With the addition of an adequate polymeric agent, poly(ethylene oxide) (PEO), spinodal decomposition was induced in the course of polymerization of GDMA. A homogeneous gelation by ATRP solidified the temporal biphasic morphology of spinodal decomposition, resulting in well-defined macroporous gels after drying. Macroporous dried gels obtained in this way comprise interconnected skeletons and macropores, which is characteristic for spinodal decomposition. Macropore size and volume were controlled simply by altering the starting composition. The mechanism of spinodal decomposition is deduced that the separation takes place between polymerizing GDMA and PEO, but FTIR and thermal analyses suggested the amount of PEO that is distributed in GDMA-rich phase cannot be neglected. Free radical polymerization, which is generally utilized for synthesis of porous polymeric gels, usually leads to heterogeneous cross-linking forming local microgels and hinders the occurrence of spinodal decomposition in a cross-linking system over extended length scales. On the other hand, living polymerization allowed homogeneous cross-linking; hence, isotropic spinodal decomposition was induced in the copresence of PEO. The facile synthesis method presented here will lead to more precise control of pore properties of cross-linked organic polymer gels.