Phase Segregation in Multicomponent Polymer Mixtures

9807601 Olvera该基金支持多组分聚合物混合物相分离的理论研究。聚合物共混物是高度不混溶的粘性流体。在多相分解过程中观察到复杂的微观结构。分解流体的形态预计会受到流动的影响。在这里，将系统地研究水动力对分解过程的影响，作为混合组分的浓度和聚合程度的函数，以及它们的净排斥相互作用。将分析分解为两相和三相的混合物。水平集理论将用于分析界面行为。此外，还将研究外源流作用下随时间变化的微观结构。初步结果表明，在三元共混物中发现的相互连接图案的破裂是强烈的非线性的。也就是说，在多数对称相的界面上生长的富含少数成分的第三相形成连接流体细丝，这些细丝分裂成母滴和卫星滴。这一机制极大地影响了少数相的生长速度。该基金支持多组分聚合物混合物相分离的理论研究。聚合物共混物是高度不混溶的粘性流体。大多数商用聚合物实际上是共混物。在多相分解过程中观察到复杂的微观结构。这些微观结构影响了共混物的性能。分解流体的形态预计会受到流动的影响。在这里，将系统地研究水动力对分解过程的影响，作为混合组分的浓度和聚合程度的函数，以及它们的净排斥相互作用。* * *

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. ***