Phase Segregation in Multicomponent Polymer Mixtures

9807601奥尔维拉这笔赠款支持多组分聚合物混合物中相分离的理论研究。聚合物共混物是高度不相容的粘性流体。在分解成多个相的过程中观察到复杂的显微组织。预计分解流体的模式会受到流动的影响。在这里，将系统地研究流体动力学对分解过程的影响，作为混合组分的浓度和聚合度的函数，以及它们的净排斥作用。将对分解成两相和三相的混合物进行分析。水平集理论将被用于分析界面行为。此外，还将研究外加流体作用下的时间相关微观结构。初步结果表明，在三元共混物中发现的相互连接的模式的分解是强烈的非线性。也就是说，在大多数对称相界面上生长的富含少数组分的第三相形成了连接流体细丝的连接，这些液丝分裂成母滴和卫星液滴。这一机制极大地影响了少数相的生长速度。%这笔赠款支持多组分聚合物混合物中相分离的理论研究。聚合物共混物是高度不相容的粘性流体。大多数商用聚合物实际上是共混物。在分解成多个相的过程中观察到复杂的显微组织。这些微观结构会影响共混物的性能。预计分解流体的模式会受到流动的影响。在这里，将系统地研究流体动力学对分解过程的影响，作为混合组分的浓度和聚合度的函数，以及它们的净排斥作用。***

9807601 Olvera This grant supports theoretical research on phase segregation in multicomponent polymer mixtures. Polymer blends are highly immiscible viscous fluids. Complex microstructures are observed during the decomposition into multiple phases. The patterns of the decomposing fluids are expected to be affected by flow. Here a systematic study will be conducted of hydrodynamic effects on the decomposition process as a function of the concentrations and degrees of polymerization of the blend components, as well as of their net repulsive interactions. Blends decomposing into two and three phases will be analyzed. Level set theory will be used to analyze interface behavior. The time-dependent microstructures under externally applied flow will also be studied. Preliminary results suggest that the break-up of the interconnected patterns found in ternary blends is strongly nonlinear. That is, the third phase rich in the minority component growing at the interfaces of the majority symmetric phases forms connecting fluid filaments that break up into mother drops with satellite droplets. This mechnaism greatly affects the growth rate of the minority phase. %%% This grant supports theoretical research on phase segregation in multicomponent polymer mixtures. Polymer blends are highly immiscible viscous fluids. Most commercially available polymers for applications are actually blends. Complex microstructures are observed during the decomposition into multiple phases. These microstructures affect the properties of the blends. The patterns of the decomposing fluids are expected to be affected by flow. Here a systematic study will be conducted of hydrodynamic effects on the decomposition process as a function of the concentrations and degrees of polymerization of the blend components, as well as of their net repulsive interactions. ***