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首页> 外文期刊>Journal of Applied Polymer Science >Synthesis and properties of liquid crystalline polyurethane elastomers
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Synthesis and properties of liquid crystalline polyurethane elastomers

机译：液晶聚氨酯弹性体的合成与性能

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Novel type of mesogenic chain extenders used in this study are N,N'-bis(4-hydroxyphenyl)-3,4,3',4'-biphenyldicarboxyimide (BPDI) and N,N'-bis [4-(6-hydroxyhexyloxy) phenyl]-3,4,3',4'-biphenyldicarboxyimide (BHDI). BHDI has a flexible spacer of 6-methylene units but BPDI does not. The liquid crystalline polyurethane elastomers were synthesized from BPDI or BHDI as a mesogenic chain extender, 4,4'-diphenylmethane diisocyanate, and poly(oxytetramethylene)glycol (MW 1000) as a soft segment. Polyurethane based on BHDI exhibited two melting transitions. However, any melting behavior was not shown in the BPDI-based polyurethanes because of higher melting temperature than decomposition temperature. The composition of polyurethanes was varied as a means of manipulating liquid crystalline behavior and physical properties. The BHDI-based polyurethanes containing above 50 wt % of hard segment content exhibited nematic liquid crystal behaviors. As the hard segment content of the BHDI-based polyurethanes increased, the glass transition temperature (T-g), strength, modulus, and the amount of hydrogen bonding increased. (C) 2000 John Wiley & Sons, Inc. [References: 26]
机译：在这项研究中使用的新型介晶扩链剂是N，N'-双（4-羟苯基）-3,4,3'，4'-联苯二羧酰亚胺（BPDI）和N，N'-双[4-（6-羟基己氧基）苯基] -3,4,3'，4'-联苯二羧酰亚胺（BHDI）。 BHDI具有6-亚甲基单元的柔性间隔基，而BPDI没有。液晶聚氨酯弹性体是由BPDI或BHDI作为介晶扩链剂，4,4'-二苯基甲烷二异氰酸酯和聚（氧四亚甲基）二醇（MW 1000）作为软链段合成的。基于BHDI的聚氨酯表现出两个熔融转变。但是，由于熔融温度高于分解温度，因此在基于BPDI的聚氨酯中未显示任何熔融行为。改变聚氨酯的组成作为控制液晶行为和物理性质的手段。含有大于50wt％的硬链段含量的基于BHDI的聚氨酯表现出向列型液晶行为。随着BHDI基聚氨酯硬链段含量的增加，玻璃化转变温度（T-g），强度，模量和氢键数量增加。 （C）2000 John Wiley＆Sons，Inc. [参考：26]

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