...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Polymer: The International Journal for the Science and Technology of Polymers >Layer structures 12. Chiral sanidic polyesters derived from 2,5-bis(hexadecyloxy)terephthalic acid, 2,5-bis((S)-2-methylbutoxy)terephthalic acid and 4,4 '-dihydroxybiphenyl
【24h】

Layer structures 12. Chiral sanidic polyesters derived from 2,5-bis(hexadecyloxy)terephthalic acid, 2,5-bis((S)-2-methylbutoxy)terephthalic acid and 4,4 '-dihydroxybiphenyl

机译：层结构12.由2,5-双（十六烷基氧基）对苯二甲酸，2,5-双（（S）-2-甲基丁氧基）对苯二甲酸和4,4'-二羟基联苯衍生的手性卫生型聚酯

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Three homopolyesters were prepared by polycondensation of 4,4'-dihydroxybiphenyl and 2,5-bis(n-octyloxy)-, 2,5-bis(dodecyloxy)- or 2,5-(hexadecyloxy)terephthaloylchloride. Furthermore, several copolyesters were synthesized from 4,4'-dihydroxybiphenyl and mixtures of 2,5-bis(hexadecyloxy)terephthaloylchloride and 2,5-bis((S)isopentyloxy)terephthaloylchloride. All polyesters were characterized by inherent viscosities, elemental analyses, H-1 n.m.r. spectroscopy, d.s.c. measurements, dynamic mechanical analyses (DMA), WAXS powder patterns at various temperatures and optical microscopy. Two liquid crystalline (LC) phases were detected for the homopolyesters and most copolyesters: a viscous sanidic (biaxial nematic) phase and, at higher temperatures, a mobile nematic phase. The chiral copolyesters displayed an unusual 'sausage texture', but never a Grandjean texture. A chiral nematic phase with helical main chains is discussed. (C) 1998 Elsevier Science Ltd. All rights reserved. [References: 18]
机译：通过4，4′-二羟基联苯和2，5-双（正辛氧基）-，2，5-双（十二烷氧基）-或2，5-（十六烷氧基）对苯二甲酰氯的缩聚反应制备三种均聚酯。此外，由4，4′-二羟基联苯和2，5-双（十六烷氧基）对苯二甲酰氯和2，5-双（（S）异戊氧基）对苯二甲酰氯的混合物合成了几种共聚酯。所有聚酯均以固有粘度，元素分析，H-1 n.m.r.为特征。光谱学测量，动态力学分析（DMA），各种温度下的WAXS粉末图案和光学显微镜。对于均聚酯和大多数共聚酯，检测到两个液晶（LC）相：粘性的Sanidic（双轴向列相）相和在较高温度下的移动向列相。手性共聚酯表现出不同寻常的“香肠质地”，但从未表现出格兰吉恩质地。讨论了具有螺旋主链的手性向列相。 （C）1998 Elsevier ScienceLtd。保留所有权利。 [参考：18]

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号