• 主题
高级搜索  >
历史搜索 清空历史
首页> 美国卫生研究院文献>Polymers >Synthesis and Properties of Thermotropic Copolyesters Based on Poly(ethylene terephthalate) and 4′-Acetoxy-4-biphenyl-carboxylic Acid
【2h】

Synthesis and Properties of Thermotropic Copolyesters Based on Poly(ethylene terephthalate) and 4′-Acetoxy-4-biphenyl-carboxylic Acid

机译：基于聚（乙二醇酯）和4-乙酰氧基-4-联苯 - 羧酸的热致铬共聚酯的合成与性能

代理获取
本网站仅为用户提供外文OA文献查询和代理获取服务，本网站没有原文。下单后我们将采用程序或人工为您竭诚获取高质量的原文，但由于OA文献来源多样且变更频繁，仍可能出现获取不到、文献不完整或与标题不符等情况，如果获取不到我们将提供退款服务。请知悉。
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

A series of novel copolyesters based on polyethylene terephthalate (PET) and 4′-hydroxy-biphenyl-4-carboxylic acid (HBCA) was obtained by melt polycondensation of bis(2-hydroxyethyl) terephthalate and 4′-acetoxybiphenyl-4-carboxylic acid (ABCA) as co-monomers with Sb2O3 as a catalyst. Using this synthetic procedure, a set of copolymers containing 20–80 mol% of HBCA units was prepared. According to NMR spectroscopy, the copolymers were of random composition. Copolyesters comprising 60–80 mol% of HBCA possessed increased heat resistance and formed nematic melts at 270 °C and higher. The liquid crystal (LC) phase formation was accompanied by transition to non-Newtonian characteristics of the melt flow, as well as an equalization of storage and loss moduli values. According to XRD and polarizing microscopy, the LC glassy phase of the copolyesters coexists with crystalline regions of poly-(4′-hydroxy-4-biphenylcarboxylate), non-melting up to 400 °C and above. The mechanical characteristics of these LC copolyesters showed similar or better values than those of well-known LC polymers. These novel copolyesters can be useful in obtaining heat-resistant materials with an ordered structure and, as a consequence, improved performance.
机译：基于聚对苯二甲酸乙二醇酯（PET）和4'-羟基 - 联苯基-4-羧酸（HBCA）的一系列新型共聚酯是通过双苯二甲酸酯和4'-乙酰氧基苯基-4-羧酸的熔融缩聚得到的（ABCA）作为具有SB2O3作为催化剂的共聚单体。使用该合成方法，制备含有20-80mol％HBCA单元的一组共聚物。根据NMR光谱，共聚物是随机组合物。包含60-80mol％HBCA的共聚酯具有增加的耐热性，并在270℃和更高的熔体中形成的向量熔体。液晶（LC）相形成伴随着转变为熔体流动的非牛顿特征，以及储存和损失模量值的均衡。根据XRD和偏振显微镜，共聚酯的LC玻璃相与聚 - （4'-羟基-4-联苯基羧酸羧酸甲酸酯）的结晶区域共存，非熔化至400℃和以上。这些LC共聚酯的机械特性显示出与众所周知的LC聚合物的相似或更好的值。这些新型共聚酯可用于获得具有有序结构的耐热材料，并且因此提高性能。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
代理获取

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