• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Applied Polymer Science >ANOMALOUS BEHAVIOR OF THERMOSETTING SYSTEMS AFTER CURE VS CHEMICAL CONVERSION - A NORMALIZED CONVERSION-TEMPERATURE-PROPERTY DIAGRAM
【24h】

ANOMALOUS BEHAVIOR OF THERMOSETTING SYSTEMS AFTER CURE VS CHEMICAL CONVERSION - A NORMALIZED CONVERSION-TEMPERATURE-PROPERTY DIAGRAM

机译：固化对化学转化后热固性系统的异常行为-归一化的转化温度特性图

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

Isothermal properties of thermosetting materials after cure, such as density and modulus, pass through maximum and minimum values with increasing chemical conversion. In this report observed decreases in modulus and density at isothermal temperatures below the glass-transition temperature, T-g, are termed ''anomalous.'' Four diepoxide (diglycidyl ether of bisphenol A) and tetrafunctional diamine (trimethylene glycol di-p-aminobenzoate) high T-g thermosetting systems with different ratios of amine to epoxy were investigated for the purpose of analyzing the evolution of the isothermal properties with increasing conversion. The density, T-g, and modulus of the materials with increasing conversion were measured by a combination of dilatometric, differential scanning calorimetry, and torsional braid analysis techniques. The results are presented in the form of conversion-temperature-property (TgTP) diagrams with modulus and density as the properties. T-g is used as a direct measure of conversion based on the one-to-one relationship between T-g and conversion. The property-conversion behavior of the systems with different ratios of amine to epoxy show similar behavior if T-g is used as the measure of conversion and the data are normalized with respect to T-g at a conversion corresponding to the lower limit of the conversion range at which a maximum in the isothermal modulus occurs. The conversion corresponding to molecular gelation, T-gel(g), correlates with the lower limit of the conversion range at which the maximum in isothermal modulus occurs; T-gel(g) also marks a change in the behavior of the sub-T-g mechanical relaxations vs. conversion. The conversion corresponding to the maximum in isothermal modulus vs. conversion correlates with the conversion corresponding to the maximum in isothermal density vs. conversion. (C) 1995 John Wiley & Sons, Inc. [References: 42]
机译：固化后，热固性材料的等温特性（例如密度和模量）会随着化学转化率的增加而通过最大值和最小值。在该报告中，观察到在低于玻璃化转变温度Tg的等温温度下模量和密度降低，称为“异常”。四种二环氧化合物（双酚A的二缩水甘油醚）和四官能二胺（三亚甲基二醇二对氨基苯甲酸酯）为了分析随着转化率增加等温特性的演变，研究了具有不同胺/环氧比的高Tg热固性体系。通过膨胀，差示扫描量热法和扭转编织分析技术的组合来测量随着转化率提高的材料的密度，T-g和模量。结果以具有模量和密度作为性质的转化温度-性质（TgTP）图的形式呈现。基于T-g与转化之间的一对一关系，T-g用作转化的直接量度。如果将Tg用作转化率的度量标准，并且在对应于转化率下限的转化率下将数据相对于Tg归一化，则具有不同胺/环氧比的体系的性能转化行为将显示出相似的行为。等温模量出现最大值。与分子凝胶化相对应的转化率T-gel（g）与等温模量最大时的转化率范围的下限相关。 T-gel（g）还标志着亚T-g机械弛豫与转化行为的变化。对应于等温模量对转化率的最大值的转化率与对应于等温密度对转化率的最大值的转化率相关。 （C）1995 John Wiley＆Sons，Inc. [参考：42]

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