Polymer-Polymer Interactions, Phase Behavior, and Interfaces

小行星9726484 多组分聚合物共混物（或合金）的合理开发需要了解所涉及的聚合物-聚合物相互作用以及如何控制它们，以产生具有有用机械性能的材料，获得光学透明的混合物。（相容性），分散在脆性基体的抗冲改性剂，反应增容不混溶的混合物等，这一建议概述了一个程序，用于获得定量信息对一些重要的聚合物重复单元之间的相互作用。该方法涉及实验观察的共混体系的相行为进行了分析，在适当的理论混合相结合的平均场二元相互作用模型。 实验方法包括共聚物组成图、临界分子量法、相图定量分析、光散射和中子反射率。 具体目的包括（a）比较具有各种侧基的丙烯酸酯和甲基丙烯酸酯单体单元与其它聚合物的相互作用，（B）重复单元中的溴原子对与其它聚合物的相互作用的影响，（c）开发可与苯乙烯/丙烯腈共聚物（SAN）混溶的反应性共聚物，用于工程热塑性塑料与ABS材料的反应性增容，以及（d）通过中子反射率测量的聚合物-聚合物界面厚度与使用本程序中确定的相互作用能从理论预测的那些厚度的比较。 中子反射率研究将在成对的商业上重要的聚合物上进行，如聚碳酸酯、聚（亚苯基醚）等与共聚物，例如，苯乙烯与丙烯腈，马来酸酐等的实验将与国家标准和技术研究所和工业合作进行。 此外，本研究将使用最近建造的光散射装置对所选共混物的相分离动力学进行系统的研究。 这将提供用于评价相互作用能以及关于聚合物-聚合物扩散系数的信息的失稳温度-组成曲线的准确评估。 这项基础研究的结果将是关于聚合物重复单元对之间相互作用的定量信息，用于设计具有或可能具有技术重要性的均匀或相分离的聚合物共混物（或合金）。 这项研究将为各级学生提供宝贵的教育经验，包括研究生，博士，本科和高中。 ***

9726484 Paul The rational development of multicomponent polymer blends (or alloys) requires an understanding of the polymer-polymer interactions involved and how to control them in order to generate materials with useful mechanical properties, obtain optically clear mixtures. (miscibility), disperse impact modifiers in a brittle matrix, reactively compatibilize immiscible mixtures, etc. This proposal outlines a program for obtaining quantitative information on the interactions between pairs of a number of important polymer repeat units. The methodology involves experimental observations of the phase behavior of blend systems that are analyzed in terms of appropriate theories of mixing combined with a mean field binary interaction model. The experimental methods involve copolymer composition mapping, the critical molecular weight method, quantitative analysis of phase diagrams, light scattering, and neutron reflectivity. Specific objectives involve (a) comparison of interactions of acrylate and methaclylate monomer units having various pendant groups with other polymers, (b) effect of bromine atoms in the repeat unit on interactions with other polymers, (c) development of reactive copolymers that are miscible with styrene/acrylonitrile copolymers (SAN) for use in reactive compatibilization of engineering thermoplastics with ABS materials, and (d) comparison of polymer-polymer interfacial thicknesses measured by neutron reflectivity with those predicted from theory using interaction energies determined in this program. The neutron reflectivity studies will be performed on pairs of commercially important polymers like polycarbonate, poly(phenylene ether), etc. with copolymers, e.g., styrene with acrylonitrile, maleic anhydride, etc. The experiments will be done in collaboration with the National Institute of Standards and Technology and industry. In addition, the research will make a systematic study of the kinetics of phase separation of selected blends using a recently constructed light scattering apparatus. This will provide accurate assessment of spinodal temperature-composition curves for use in evaluation of interaction energies as well as information about polymer-polymer diffusion coefficients. %%% The results of this fundamental research will be quantitative information about interactions between polymer repeat unit pairs for use in designing homogeneous or phase separated polymer blends (or alloys) that either are or may be of technological importance. This research will provide a valuable educational experience for students at all levels including postgraduate, PhD, undergraduate, and high school. ***