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分别用乙二胺 (EDA)和水作为扩链剂制备了聚氨酯脲 聚甲基丙烯酸甲酯 (PUA)水分散液 .借助DSC、DMA、FTIR研究了扩链剂对PUA的结构和性能的影响 .结果表明在EDA扩链体系中 ,虽然聚甲基丙烯酸甲酯 (PMMA)和聚酯软段以及扩链剂与异氰酸酯生成的硬段均有一定程度的相容性 ,但由此合成的PUA仍具有多相结构 ;水扩链体系只有一个较宽的二级转变区 ,各相之间有较大程度的混合 .由EDA扩链合成的PUA在耐溶剂、耐水性及拉伸强度等方面优于水扩链体系 .两种扩链剂体系所得PUA的性能差异 ,主要与二者和异氰酸酯反应生成的脲键密度不同 ,导致不同的微相结构有关
Polyurethaneurea aqueous solution of poly (methyl methacrylate) (PUA) was prepared by using ethylenediamine (EDA) and water as chain extenders respectively.The effects of chain extender on the structure and properties of PUA were studied by means of DSC, DMA and FTIR The results showed that in the EDA chain extension system, though the compatibility between PMMA and polyester soft segment and the chain extender and the hard segments generated by isocyanate were some extent, the synthesized PUA There is still a multi-phase structure; water chain system has only a wide second-order transition zone, a large degree of mixing between the various phases. PUA synthesized by EDA chain in the solvent resistance, water resistance and tensile strength and so on Which is better than that of water-chain-extended system.The differences of the properties of PUA obtained by the two chain extenders are mainly due to the different densities of urea bonds formed by the reaction of the two with isocyanate, resulting in different microfacies