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On phase equilibria, interfacial tension and phase growth in ternary polymer blends
Author(s) -
He David Qiwei,
Kwak Soonjong,
Nauman E. Bruce
Publication year - 1996
Publication title -
macromolecular theory and simulations
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.37
H-Index - 56
eISSN - 1521-3919
pISSN - 1022-1344
DOI - 10.1002/mats.1996.040050502
Subject(s) - binodal , spinodal , spinodal decomposition , ternary operation , thermodynamics , polymer blend , surface tension , phase (matter) , phase diagram , component (thermodynamics) , polymer , surface energy , materials science , chemistry , polymer chemistry , physics , copolymer , composite material , organic chemistry , computer science , programming language
A gradient squared free energy functional of the Landau‐Ginzburg type is combined with Flory‐Huggins theory to calculate minimum domain sizes, concentration profiles and interfacial tensions in ternary polymer blends. The dynamic equations governing spinodal decomposition are linearized to show that the minimum size for growth is identical to the thermodynamic minimum on phase volume. It is shown that unseparated, third components are enriched at the interface, reduce interfacial tension, increase stability and increase the minimum domain sizes. Enrichment of the third component at the interface causes concentrations at the major components to lie outside their binodal limits at a distance from the interface. Although the effects are most pronounced when the third component is a compatibilizer, the general phenomena remain true even when the third component is relatively incompatible. Generalizations to blends of N components are presented, and a robust method for calculating multicomponent phase diagrams is described.