Small Grants for Exploratory Research: Thermodynamic Constraints on Reactive Melt Processing of Multicomponent Systems

反应物和产物均处于液相和固相（不存在气相）的反应系统被商业上用于生产高分子量单体或用于生产特种和商品聚合物的中间体。具体的例子包括双酚A、对氯苯和n-甲基邻苯二胺。其他必须在熔体中加工的材料包括元素和化合物半导体，如硅和砷化镓，以及超导材料，如钡/铜/钇/氧系统。其中一些两相系统的一个优点是反应和分离在同一单元进行，大大降低了处理成本。多组分固液相图的结构和性质在决定这些单元操作（也称为熔体处理单元）的行为方面起着重要作用。PI计划发展一个广泛的多组分反应固液相图的综合理论，这将产生构思和设计熔体处理系统的实用规则。当反应存在时，这些体系具有不寻常的相平衡行为，包括在理想混合物中出现反应性共沸物。这些和其他在非理想混合物中具有正常共沸物的特征。平衡行为的这些和其他特征影响了在反应分离系统中什么能实现，什么不能实现。PI计划使用微分几何中的某些不变量来提供相行为的完整分类，并最终根据对平衡关系的不完全了解来预测它。最终目标是发展对反应熔体加工的广泛的基本理解，这将为这种系统的合成和设计提供有用的指导方针。

Reaction systems where both reactants and products are in the liquid and solid phase (no vapor phase present) are being used commercially to produce high molecular weight monomers or intermediates used in the production of specialty and commodity polymers. Specific examples include bisphenol A, paradichloro-benzene and n-methyl phthalimide. Other classes of materials that must be processed in the melt include elemental and compound semi-conductors such as silicon and gallium arsenide, and superconducting materials such as barium/copper/yttrium/oxygen systems. One advantage of some of these two phase systems is that reaction and separation occur in the same unit, greatly reducing processing costs. The structure and properties of multicomponent solid-liquid phase diagrams play and important role in determining the behavior of these unit operations (also referred to as melt processing units). The PI plans to develop a broad comprehensive theory of multicomponent reactive solid-liquid phase diagrams that will produce practical rules for conceiving and designing melt processing systems. These systems have unusual phase equilibrium behavior when reactions are present, including the appearance of reactive azeotropes in ideal mixtures. These and other features normal azeotropes in non-ideal mixtures. These and other features of the equilibrium behavior influence what can and cannot be achieved in reaction-separation systems. The PI plans to use certain invariants from differential geometry to provide a complete classification of the phase behavior, and ultimately to predict it, from an incomplete knowledge of the equilibrium relations. The ultimate goal is to develop a broad fundamental understanding of reactive melt processing that will lead to useful guidelines for the synthesis and design of such systems.