Determining the Relation Between Molecular Structure and Macroscopic Heat Transport in Oriented and Stressed Polymers.

技术综述：对固体聚合物各向异性导热系数的来源进行了实验研究。特别是，寻求聚合物的分子结构和由此产生的宏观性质之间的关系。已经确定：(1)变形的交联弹性体表现出各向异性的热导张量，(2)对于处于相同状态的聚合物，张量k与额外应力张量线性相关，(3)对于所研究的少数体系，如果适当地进行无量纲处理，这两个量的关系的常量表现出的普适值为0.03，与所研究的少数体系的化学无关。在这项工作中，设计了一组实验，以区分描述这些观察结果的相互竞争的理论。使用了一种名为强迫瑞利光散射的非侵入性光学技术来检测新的材料状态。这项研究的结果将对含塑料的先进材料的运输模型产生广泛的影响。目前的工作，如果成功，应该确定相似原理是否适用于固体聚合物在冷却过程中。非技术摘要：提出了一项关于固体聚合物(如塑料)如何在不同方向上不同热流动的起源的实验研究。特别是，寻找分子的行为方式和由此产生的热流特性之间的关系。在这项工作中，设计了一系列实验，以区分使用一种名为强迫瑞利光散射的非侵入性光学技术来描述这些观测的相互竞争的理论。结果必然会在关于这种效应的起源的相互竞争的理论之间产生差异。这项研究的结果将对含有塑料的先进材料的建模产生广泛的影响。目前的工作，如果成功，将确定类似的原理是否适用于冷却过程中的固体聚合物。第二，作为该项目的一部分，将向芝加哥的全息博物馆提供一个展示，解释所采用的关键光学技术。参观者将了解到文献学是用来研究材料特性的，以及这项技术是如何使用的。

TECHNICAL SUMMARY:An experimental study into the origins of anisotropic thermal conductivity of solidpolymers is proposed. In particular, a relationship between the molecular structure ofthe polymer and the resulting macroscopic properties is sought. It has already beenestablished that (1) deformed, cross-linked elastomers exhibit an anisotropic thermalconductivity tensor, k (2) the tensor k is linearly related to the extra stress tensor,for the polymer in the same state, and (3) the constant of relation for these twoquantities exhibits a universal value of 0.03, independent of chemistry for the fewsystems studied, when properly made dimensionless. In this work a set of experimentshas been designed that will distinguish between competing theories to describe theseobservations. A non-invasive optical technique called Forced Rayleigh Light Scatteringto examine novel material states is used. Results will necessarily distinguish betweencompeting theories on the origins of the effect.The results of the study will have broad impact on the transport modeling of advancedmaterials containing plastic. While previous work showed how non-isothermalmodeling of liquids requires an additional complexity because of anisotropy, it alsosuggested that this complexity could be easily modeled through use of a phenomenologicalrelation to stress. The current work, if successful, should determine if similarprinciples apply to the solid polymer during cooling.NON-TECHNICAL SUMMARY:An experimental study into the origins of how heat flows differently in differentdirections for solid polymers, such as plastic, is proposed. In particular, a relationshipbetween how the molecules are behaving and the resulting heat-flow propertiesis sought. In this work a set of experiments has been designed that will distinguishbetween competing theories to describe these observations using a non-invasive opticaltechnique called Forced Rayleigh Light Scattering. Results will necessarily distinguishbetween competing theories on the origins of the effect.The results of the study will have broad impact on the modeling of advanced materialscontaining plastic. While previous work showed how temperature modeling of theseliquids requires an additional complexity, it also suggested that this complexity couldbe easily modeled through use of a simple relation to stress which is typically calculatedalready. The current work, if successful, should determine if similar principlesapply to the solid polymer during cooling.Secondly, as part of the project, a display explaining the key optical technique employedwill be provided to the Holography Museum in Chicago. Visitors will learn thatholography is used to study material properties, and how the technique is employed.