Flow Morphology of Microphase-Separated Block Copolymers

本研究的目的是了解微相分离嵌段共聚物在强分离极限下的流动机理。微相分离嵌段共聚物是一种化学复合材料，在许多先进材料的配方中发挥着重要的作用。新材料设计需要深入了解组成材料的物理原理以及它们的物理与工艺的相互作用。研究主要集中在三个方面：第一，利用小角中子散射直接观察嵌段共聚物在固体激光器中的流动形态。其次，他们将对宏观有序的中间相样品和各向同性材料的流变性进行全面比较。第三，他们将阐明中间相形状对线粘弹性性质的影响。由于微相分离嵌段共聚物非常类似于混合良好的不相容聚合物共混物，因此所进行的实验还将涉及聚合物热力学中的一般问题，例如剪切二元混合物是否会影响其相图。

The aim of this research is to understand the flow mechanism of microphase-separated block copolymers in the strong-segregation limit (SSL). Microphase-separated block copolymers are chemically composite materials which play a prominant role in the formulation of many advanced materials. New material design requires an in- depth understanding of the physics of the component materials and of the interaction of their physics with processing. The research focusses on three tasks: First, they intend to observe directly the flow morphology of block copolymers in the SSL using small-angle neutron scattering. Second, they will do a comprehensive comparison between the rheological properties of samples with macroscopically ordered mesophases versus isotropic materials. Third, they will elucidate the impact of mesophase shape on linear-viscoelastic properties. Since microphase- separated block copolymers are very much like well-mixed incompatible polymer blends, the experiments performed will also bear on general questions in polymer thermodynamics, such as whether shearing a binary mixture can affect its phase diagram.