• 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 >Reconstruction of histograms of the Glass Transition Temperature of Free Radical Copolymers from DSC Thermograms
【24h】

Reconstruction of histograms of the Glass Transition Temperature of Free Radical Copolymers from DSC Thermograms

机译：从DSC热谱图重建自由基共聚物的玻璃化转变温度的直方图

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

Most polymeric materials appear as complex mixtures of macromolecules characterized by distributions of specific properties that are essential to the quality of these products. among such properties, the accurate determination of the glass transition temperature, and therefore, accurate representation of it, is a key issue. When analyzed using dynamci scanning calorimetry (DSC) techniques, many copolymers exhibit a wide range of temperature over which the glass transition takes place, and the width of the transition region is therefore, not satisfactorily described by average T_g values, for example tose computed from tangent curves drawn on thermograms. This article describes a method that allows us to charcterize this spreading of the glass transition region by reconstructing weighted T_g distriutions from DSC thermograms. As such an objective might appear as questionable from a strictly physical point of view, the significance of what is meant by“distribution”is specified in the text. A model is proposed that accounts for relaxation phenomena. The approach is validated by exam-ining samples of BuA/Sty emlsion copolymers produced at different overall conversions and compositions, and examining the corresponding histograms of T_g were computed. The results show that accurate and consistent information on the glass transition behavior of the copolymer is obtained, and that the effective distribution is clearly connected with the composition drift in the polymer particles. The proposed algorithm allows one to obtain a maximum amount of informaiton from DSC measurements, and provides a deeper insight into the“history”of complex polynmer mixtures.
机译：大多数聚合物材料以大分子的复杂混合物形式出现，其特征是特定性质的分布，这些性质对于这些产品的质量至关重要。在这些特性中，玻璃化转变温度的准确确定以及因此的准确表示是关键问题。当使用动态扫描量热法（DSC）技术进行分析时，许多共聚物表现出很大的温度范围，在该温度范围内发生玻璃化转变，因此，平均T_g值不能令人满意地描述转变区的宽度，例如，在热分析图中绘制的切线曲线。本文介绍了一种方法，该方法允许我们通过从DSC温度记录图中重建加权的T_g分布来表征玻璃化转变区域的这种扩展。由于从严格的物理角度来看，这样的目标可能令人怀疑，因此在本文中详细说明了“分配”的含义。提出了解决松弛现象的模型。该方法通过检查在不同总体转化率和组成下生产的BuA / Sty emlsion共聚物样品进行验证，并计算了相应的T_g直方图。结果表明获得了关于共聚物的玻璃化转变行为的准确和一致的信息，并且有效分布与聚合物颗粒中的组成漂移明显相关。所提出的算法允许人们从DSC测量中获得最大的信息量，并提供了对复杂聚合物混合物“历史”的更深入的了解。

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