Reactive Polymer Blending

热塑性塑料的一个重要趋势是基于聚合物-聚合物共混物的产品的增长。它们被称为“工程”热塑性塑料，因为它们具有足够高的模数、韧性和软化温度，可以像使用金属一样使用。大多数共混物是不相容的，但通过在相间界面接枝或嵌段共聚，稳定在高度分散的形态中。制造这些共聚物的一种方法是在熔融共混过程中进行偶联反应。这项研究将集中在两种不相容聚合物的混合物上，一种是刚性的(玻璃化转变温度高于常温)，另一种是柔软的(玻璃化转变温度低于常温)。最初，这两个相都是无定形的。该策略将设计几个模型反应性聚合物对，并将它们组合在一个小型实验室熔体混合器中，该混合器复制了工业规模过程的基本特征。PI计划通过改变组成、化学、聚合物结构和链长来确定控制过程的主要变量。扫描和透射电子显微镜将作为主要的微观结构表征方法。通过对这些显微照片的图像分析和单滴研究，可以模拟具有界面反应的液滴破碎和合并过程。这项研究将为这些聚合物共混物的分析提供更好的方法，并对工艺和新的共混物增容方法和材料有一个基本的了解。

An important trend in thermoplastics is the growth of products based on polymer-polymer blends. They are called "engineered" thermoplastics because they have high enough modulus, toughness and softening temperature to be used the same way metals are used. Most of these blends are immiscible but stabilized in a highly dispersed morphology by graft or block copolymers at the interface between the phases. One way to make these copolymers is by coupling reactions during melt blending. This research will focus on blends of two immiscible polymers, one rigid (glass transition temperature greater than ambient temperature) the other soft (glass transition temperature less than ambient temperature). Initially both phases will be amorphous. The strategy will be to design several model reactive polymer pairs and combine them in a small laboratory melt mixer which duplicates the essential features of the industrial scale process. The PIs plan to identify the major variables controlling the process by changes in composition, chemistry, polymer architecture and chain length. Scanning and transmission electron microscopy will be used as the major microstructural characterization method. From image analysis on these micrographs and single drop studies, the drop break up and coalescence process with interfacial reaction will be modeled. This research should yield better methods for the analysis of these polymer blends as well as a fundamental understanding of the process and new blend compatibilizing methods and materials.