Phase Equilibria and Self-Organization Behavior of Rigid-Rod Polymer Mixtures

9529296 Kyu本项目的主要目标是阐明含有刚性棒分子的可结晶聚合物混合物的相平衡和自组织行为。为了考虑相分离和中间相有序的耦合，他们结合了Flory-Huggins各向同性混合理论和Maier-Saupe向列相有序理论，考虑了具有两个向列相-各向同性转变的两个取向有序参数。在传统的柔性均聚物结晶热力学或动力学理论中，通常忽略了分子取向的影响，尽管众所周知，柔性分子在折叠过程中确实会相互排列。它们将考虑链取向对结晶的影响，这是目前柔性均聚物结晶理论中所缺少的。用时间分辨散射研究了刚性棒混合物的结晶动力学和相分离动力学之间的耦合。%这是一项重要的建议，它提高了将不同材料家族的各种理论预测整合到一个连贯的图景中的可能性，尤其是在先进的聚合物和混合物中。***

9529296 Kyu This primary objective of the present project is to elucidate phase equilibria and self-organization behavior of crystallizable polymer blends containing rigid-rod molecules. To account for the coupling of phase separation and mesophase ordering, they have combined Flory-Huggins theory for isotropic mixing and Maier-Saupe theory for nematic ordering of binary nematic mixtures by taking into consideration the two orientational order parameters having two nematic-isotropic transitions. Customarily, the effect of molecular orientation has been ignored in the conventional thermodynamic or kinetic theory of crystallization of flexible homopolymers, although it has been generally known that flexible molecules indeed align among themselves during chain folding. They will incorporate the effect of chain orientation on the crystallization which is missing in the current crystallization theory of flexible homopolymers. The coupling between crystallization kinetics and phase separation dynamics of rigid-rod mixtures will be investigated by time-resolved scattering. %%% This is an important proposal that raises the potential for incorporating various theoretical predictions from different families of materials into a coherent picture with particular emphasis in advanced polymer and blends. ***