Dudowicz Jacek, Douglas Jack F, Freed Karl F
The James Franck Institute and the Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, USA.
Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
J Chem Phys. 2014 Jun 28;140(24):244905. doi: 10.1063/1.4884123.
In contrast to mixtures of two small molecule fluids, miscible binary polymer blends often exhibit two structural relaxation times and two glass transition temperatures. Qualitative explanations postulate phenomenological models of local concentration enhancements due to chain connectivity in ideal, fully miscible systems. We develop a quantitative theory that explains qualitative trends in the dynamics of real miscible polymer blends which are never ideal mixtures. The theory is a synthesis of the lattice cluster theory of blend thermodynamics, the generalized entropy theory for glass-formation in polymer materials, and the Kirkwood-Buff theory for concentration fluctuations in binary mixtures.
与两种小分子流体的混合物不同，可混溶的二元聚合物共混物通常表现出两个结构弛豫时间和两个玻璃化转变温度。定性解释假定了在理想的、完全可混溶体系中由于链连接性导致局部浓度增强的唯象模型。我们发展了一种定量理论，该理论解释了实际可混溶聚合物共混物（其绝非理想混合物）动力学中的定性趋势。该理论是共混热力学的晶格簇理论、聚合物材料玻璃形成的广义熵理论以及二元混合物浓度涨落的柯克伍德 - 布夫理论的综合。
