Compatibilization of Polymer Blends

新型“工程”热塑性塑料是聚合物-聚合物共混物 其具有高模量、良好的韧性和高软化度 温度 因此，它们可以用于设计 通常需要金属的结构。 其它聚合物 共混物具有特殊的性质，允许它们用于 特殊应用。 大多数混合物是由两种 或熔融状态的更不混溶的聚合物。 他们的 必须稳定多相结构以防止聚结 当共混物通过聚合物加工机挤出或模塑时。 增容的主要方法是使用嵌段 共聚物，其可以像聚合物皂一样起作用以稳定聚合物。 形态学 该嵌段共聚物可以预制并 混合到混合物中，或者它可以通过以下方式原位形成： 两个不同链之间的偶联反应。 计划进行一项研究计划，以了解和控制 在熔融混合期间形成的形态。 两个模型对 的不混溶聚合物，聚苯乙烯（PS）和聚（2- 乙烯基吡啶）PVP和线性低密度聚乙烯（LLPE） 和聚（乙烯-共聚-聚丙烯）PEP将用作测试 材料. LLDPE/PEP系统提供了独特的机会 因为它可以在高温下混溶。 从可混溶熔体中沉淀产生的形态 将通过混合不混溶的熔体和通过反应性 偶合器. 新的和有用的形态应该由此产生 研究以及战略和定量模型， 聚合物共混物的有效增容。

New "engineered" thermoplastics are polymer-polymer blends which have a high modulus, good toughness, and high softening temperatures. They can therefore be used in designed structures which typically require metals. Other polymer blends have special properties that permit them to be used for particular applications. Most blends are made by mixing two or more immiscible polymers in the molten state. Their multiphase structure must be stabilized to prevent coalescence when the blend is extruded or molded by a polymer processor. The main method for compatibilization is to use a block copolymer which can act like a polymeric soap to stabilize the morphology. This block copolymer can be premade and compounded into the mixture or it can be formed in situ by coupling reactions between the two different chains. A research program is planned to understand and control the morphology which develops during melt mixing. Two model pairs of immiscible polymers, polystyrene (PS) and poly(2- vinylpyridine) PVP, and linear low density polyethylene (LLPE) and poly(ethylene-co-polypropylene) PEP will be used as test materials. The LLDPE/PEP system offers unique opportunities since it can be made miscible at elevated temperatures. Morphologies created by precipitation from the miscible melts will be compared by mixing immiscible melts and by reactive coupling. New and useful morphologies should result from this research as well as strategies and quantitative models for efficient compatibilization of polymer blends.