MORPHOLOGY AND PROPERTIES OF SEGMENTED POLYETHER POLYURETHANEUREAS
MORPHOLOGY AND PROPERTIES OF SEGMENTED POLYETHER POLYURETHANEUREAS
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DOI：
10.1021/ma00239a014
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发表时间：
1983-01-01
期刊：
影响因子：
5.5
通讯作者：
COOPER, SL
中科院分区：
文献类型：
--
作者：
WANG, CB;COOPER, SL
合成了以4,4′-亚甲基双（异氰酸苯酯）、乙二胺和分子量为1000或2000的聚四亚甲基氧化物为主要原料的聚醚聚氨酯（PEUU）。利用差示扫描量热法、动态力学、应力-应变、应力滞后和红外二色性实验研究了尿素连接、硬段含量和块段长度对相分离程度、畴结构和物理性能的影响。这些聚氨酯的机械性能主要取决于样品的硬段含量，尽管PEUU-2000系列中较高浓度的尿素基团在类似硬段重量分数下的性能优于PEUU-1000系列。硬畴内三维氢键的存在导致了异常强的硬畴内聚。随着硬段含量的减少，形貌由相互连接的硬畴向更加孤立的硬畴转变。描述了链段在任一畴内和界面区域的取向行为，并与样品形貌有关。
Two series of polyether polyurethaneureas (PEUU) based on 4, 4'-methylenebis (phenylene isocyanate), ethylenediamine, and either 1000 or 2000 molecular weight poly (tetramethylene oxide) were synthesized. The effect of the urea linkage, hard segment content, and block length on the extent of phase separation, domain structure, and physical properties was studied by utilizing differential scanning calorimetry, dynamic mechanical, stress-strain, stress hysteresis, and infrared dichroism experiments. The mechanical properties of these polyurethanes depend primarily on the sample’s hard segment content, although a higher concentration of urea groups in the PEUU-2000 series results in properties superior to those of the PEUU-1000 series at similar hard segment weight fractions. The presence of three-dimensionalhydrogen bonding within hard domains leads to the unusually strong hard domain cohesion. Upon decrease of the hard segment content, a change of morphology from interconnectingto more isolated hard domains took place. Orientation behavior of chain segments within either domainand in the interfacial region is described and related to sample morphology.