Complex Fluids from Model Polyolefins

本研究是对含聚甲基丁烯-聚乙烯丁烯嵌段共聚物（PMB-PEB）的聚甲基丁烯（PMB）和聚甲基丁烯（PEB）共混物的热力学性质进行研究，以考察形成复杂流体的可能性。小角中子散射和光散射将是本研究的主要工具。所需的模型聚合物将通过双烯在高真空下的“活”阴离子聚合和随后的氢化或氘化来合成，以产生中子散射对比。拟议的研究将分为两个阶段。首先，通过对均匀单相混合物的小角中子散射测量，获得PMB/PEB/PMB-PEB混合物的混合热力学。这些数据将为相分离系统中分散相的合理设计提供热力学依据。第二阶段将包括审查这些系统。两相结构的演化将通过时间分辨小角中子散射和光散射测量在热力学不稳定混合物上进行研究。实验的设计使得从单相系统到两相系统的转变温度在实验上可以达到（在170℃附近）。散射实验将确定分散相的形状和大小，嵌段共聚物的界面活性，以及形态是否处于平衡状态。这些聚合物属于最大和最重要的共混聚合物家族之一，即由聚烯烃-聚乙烯，聚丙烯，聚丁烯及其共聚物产生的聚合物。尽管它们具有重要的商业意义，但实际上没有关于这些多组分系统混合的热力学数据。* * *

9307098 Balsara This research is a study of the thermodynamic properties of blends of polymethylbutene (PMB) and polyethylbutene (PEB) containing polymethylbutene-polyethylbutene (PMB-PEB) block copolymers to examine the possibility of forming complex fluids. Small angle neutron scattering and light scattering will be the primary tools for this study. The required model polymers will be synthesized by "living" anionic polymerization of dienes under high-vacuum and subsequent hydrogenation, or deuteration for creating neutron scattering contrast. The proposed study will consist of two stages. First, the thermodynamics of mixing of PMB/PEB/PMB-PEB mixtures will be obtained from small angle neutron scattering measurements on homogeneous, single-phase mixtures. These data will provide the thermodynamic basis for the rational design of the dispersed phase in phase-separated systems. The second stage will consist of examining such systems. The evolution of the two-phase structures which will be studied by time resolved small angle neutron scattering and light-scattering measurements on thermodynamically unstable mixtures. The experiments are designed so that the transition temperatures from single-phase to two-phase systems are experimentally accessible (in the vicinity of 170 C). The scattering experiments will determine the shape and size of the dispersed phase, the interfacial activity of the block copolymer, and whether or not the morphology is at equilibrium. These polymers belong to one of the largest and most important polymer blend family, namely that arising from polyolefins- polyethylene, polypropylene, polybutene and their copolymers. In spite of their commercial importance, there is virtually no data on the thermodynamics of mixing of these multi-component systems. ***