RUI: Phase Separation Behavior of Polymer Blends Modified by Copolymer Additives

该RUI奖侧重于与各种共聚物结构和浓度的添加剂的二元聚合物共混物相分离的平衡热力学和动力学。这项工作的目标是更好地了解共聚物如何影响相演化和热力学边界。在先前研究的基础上，将采用散射和模拟技术。所研究的共聚物包括随机共聚物、嵌段共聚物、多嵌段共聚物和接枝共聚物。共聚物的单体组合物还将包括某些共聚物的对称和不对称组合物。具体的实验三元体系是聚丁二烯，聚苯乙烯和各种丁二烯和苯乙烯共聚物的共混物。均聚物的分子量将分为两类，低分子量共混物和分子量大于纠缠分子量的共混物。这些系统将在适当的时候使用温度跳变广角光散射和小角中子散射（SANS）技术进行实验研究。最后，将采用蒙特卡罗计算机模拟技术对实验聚合物体系进行建模。开发具有特定性能的新型聚合物基材料通常是通过混合现有材料来尝试的。成功的混合通常是具有挑战性的，为了帮助混合，通常引入添加剂作为相容剂。在这项工作中，将研究各种增容剂对聚合物材料混合的影响，目的是更好地理解所涉及的基本过程。随着这些效应被更好地理解，这些知识可以应用于工业系统，目的是改善聚合物基材料的加工和性能。

This RUI award focuses on equilibrium thermodynamics and kinetics of phase separation in binary polymer blends with additives of various copolymer structures and concentrations. The goal of this work is to better understand how copolymers can influence phase evolution and thermodynamic boundaries. Expanding on previous research, scattering and simulation techniques will be employed. The copolymers to be studied include random, block, multi-block, and graft copolymers. The monomer composition of the copolymer will also include both symmetric and asymmetric compositions for some of the copolymers. The specific experimental ternary system is a blend of polybutadiene, polystyrene, and various copolymers of butadiene and styrene. The molecular weights of the homopolymers will be in two classes, a low molecular weight blend and a blend with molecular weight greater than the entanglement molecular weight. These systems will be studied experimentally using temperature jump wide-angle light scattering as well as small angle neutron scattering (SANS) techniques when appropriate. Lastly, Monte Carlo computer simulation techniques will be employed to model the experimental polymer systems.%%%The development of new polymer-based materials with tailored properties is often attempted through the mixing of currently existing materials. Successful mixing has often been challenging to accomplish and to aid in the mixing an additive is commonly introduced as a compatibilizer. In this work, the effects various compatibilizers have on the mixing of polymer materials will be studied with the goal being to better understand the fundamental processes involved. As these effects are better understood, the knowledge can be applied to industrial systems with the aim of improving the processing and performance of polymer-based materials.