项目名称: 多重氢键调节丙烯酰胺类单体的立构规整活性自由基聚合研究
项目编号: No.21304085
项目类型: 青年科学基金项目
立项/批准年度: 2014
项目学科: 数理科学和化学
项目作者: 陶友华
作者单位: 中国科学院长春应用化学研究所
项目金额: 26万元
中文摘要: 立构规整的丙烯酰胺类聚合物性能独特,具有很高的使用价值,但是,以sp2杂化的碳原子为端基的自由基的链增长没有立体选择性,因而很难在自由基聚合中控制丙烯酰胺类聚合物的立构规整性。本申请拟拓展"多重氢键调节的立体结构控制"策略,设计合成5种具有不同氢键位点排列顺序的能形成多重氢键的丙烯酰胺类单体,加入氢键互补配体后进行自由基聚合,通过多重氢键作用确保单体侧基具有更大的空间位阻,限制增长自由基末端C-C键的旋转,从而实现丙烯酰胺类单体在自由基聚合中的立构规整性控制。在此基础上,将RAFT聚合与"多重氢键调节的立体结构控制"策略结合,实现自由基聚合中分子量与立构规整度的双重控制。最后,从材料化学的角度,考察立构规整度及分子量对这类聚合物的性能特别是热可逆交联性能的影响。希冀丰富丙烯酰胺类聚合物的立体结构控制方法,并推动这类立构规整及分子量可控且侧基具有多重氢键的聚合物在智能材料领域的应用。
中文关键词: 多重氢键;活性自由基聚合;立体结构控制;丙烯酰胺;凝胶
英文摘要: Among the various precision polymer syntheses, the control of the stereochemistry during radical polymerization of acrylamide-based monomer is one of the most challenging topics. The difficulty in attaining the stereocontrolled radical addition is due to the free radical species with a planar sp2-like carbon, which can freely rotate around the terminal single bond. For stereocontrol of acrylamide-based monomer in radical polymerization, constructing more sophisticated hydrogen bonding mediated systems may be necessary. The strength of hydrogen bonding interaction highly depends on the number of hydrogen bonding sites as well as the sequence or the array of the proton-donor and acceptor sites.Therefore, a triple hydrogen bond with a higher association constant or a quadruple hydrogen bond may lead to stronger interaction between monomer and additive, therefore, polymers with higher syndiotacticity can be obtained. For the construction of an efficient triple or quadruple hydrogen bonding interaction, a series of the acrylamide monomers with different arrays of the hydrogen bonding sites such as 2-ureido-4[1H]-pyrimidinon (Upy) unit will be synthesized.Then, the proper mediator will be selected to insure stronger hydrogen bonding interaction and larger steric hindrance,consequently syndiotactic polymers with a high
英文关键词: Multiple Hydrogen Bond;living radical polymerization;Stereocontrol;Acrylamide;Hydrogels