Phase Separation of Ternary Mixtures: Symmetric Polymer Blends
Resource
Macromolecules,28(24),7996-8005.
Journal
Macromolecules
Journal Volume
28
Journal Issue
24
Pages
7996-8005
Date Issued
1995-11
Date
1995-11
Author(s)
Abstract
The dynamics of phase separation of ternary mixtures into two and three phases are analyzed numerically by solving the nonlinear spinodal decomposition equations in two dimensions. We find interesting interface effects during the decomposition process. Between any two α + β phases rich in components I and J respectively, the third component K segregates in the interface between a and β. We study the interface segregation effects in symmetric ternary polymer blends (i.e., with equal Flory interaction parameters between each pair of monomers and equal degrees of polymerization). This segregation phenomenon influences strongly the growth of a third phase with lowest equilibrium volume fraction. In the absence of hydrodynamics, the kinetics of the minority phase is determined by the topology of the segregation pattern initiated by the decomposition of the most unstable phases. Coarsening of the minority phase occurs at the junction of four or more majority phase domain boundaries. We examine the dynamical scaling and the growth laws for the late stages of separation into two and three phases. The growth law R(τ) ~ τ1/3 is always obeyed even when the structures are not self-similar. The self-similar regime is achieved very slowly in ternary systems. © 1995, American Chemical Society. All rights reserved.
Other Subjects
Decomposition; Growth (materials); Interfaces (materials); Mixtures; Nonlinear equations; Numerical analysis; Polymer blends; Reaction kinetics; Thermoanalysis; Topology; Interface effects; Interface segregation; Symmetric polymer blends; Ternary mixtures; Phase separation
Type
journal article