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

刚性棒聚合物混合物的相平衡和自组织行为

• 批准号: 9529296
• 负责人: Thein Kyu
• 金额: $ 25.71万
• 依托单位: University of Akron
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-01-01 至 1999-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9529296&HistoricalAwards=false
• 关键词: Phase; Equilibria; Self; Organization; Behavior

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. ***

9529296 Kyu本项目的主要目的是阐明含有刚性棒分子的可结晶聚合物共混物的相平衡和自组织行为。为了解释相分离和中间相有序化的耦合，他们通过考虑具有两个向列相-各向同性转变的两个取向有序参数，将各向同性混合的Flory-Huggins理论和二元非均相混合物的非均相有序化的Maier-Saupe理论结合起来。 通常，在柔性均聚物的结晶的常规热力学或动力学理论中忽略了分子取向的影响，尽管通常已知柔性分子在链折叠期间确实在它们之间对齐。 他们将纳入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。 刚性棒混合物的结晶动力学和相分离动力学之间的耦合将通过时间分辨散射进行研究。 这是一个重要的建议，提高了将不同材料家族的各种理论预测纳入一个连贯的画面，特别强调先进的聚合物和共混物的潜力。 ***