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机构地区:[1]华东师范大学分析测试中心,nmr实验室上海200062
出 处:《波谱学杂志》1991年第4期353-363,共11页Chinese Journal of Magnetic Resonance
基 金:国家自然科学基金
摘 要:用高分辨NMR对聚甲基硅氧烷-聚脲嵌段共聚物以及聚氰丙基甲基硅氧烷-聚脲嵌段共聚物结构进行表征,对NH形成的各种氢键进行详细的研究,同时观察了氢键在力学性能中的作用,结果发现氢键强烈地影响着力学性能。用固体~1H宽线研究这类材料的相分离状况,并总结影响相分离的因素。保持硬段含量不变,增加软段分子量使相分离程度增加;保持软段分子量不变,增加硬段含量使相分离程度降低。软、硬段之间的相互作用(如氢键)使相分离程度降低。In this paper, a series of a, CD ?diaminopropyl terminated polydimethylsiioxane-polyurea and a, w- diaminopropyl terminated polycyanopropyl methylsiloxane- polyurea were characterized by high resolution NMR. The phase separation of these polymers was studied with breadline solid state NMR. The length of the hard segment and that of the soft segment have strong effect on the extent of phase separation. The interactions between the soft segments and the hard segments ( for example, hydrogen bonding) also affect the extent of phase separation. The hydrogen bonding in these polymers was studied by high resolution ~1H NMR. In concentrated solution the relative amounts of NH peaks have little dependence on concentration. The hydrogen bondings have significant effect on mechanical properties. The more the hydrogen bondings, the better the mechanical properties are.
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