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A theoretical model for quiescent coarsening in immiscible polymer blends
Author(s) -
Hu GuoHua,
Li Huxi,
Feng LianFang
Publication year - 2002
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690481121
Subject(s) - slippage , coalescence (physics) , polymer , van der waals force , polymer blend , thermodynamics , materials science , copolymer , radius , polymer chemistry , chemistry , physics , composite material , molecule , computer security , organic chemistry , astrobiology , computer science
The coalescence rate in immiscible polymer blends predicted by all existing models is two or three orders of magnitude lower than that observed experimentally. The model developed in this study considers for the first time that coarsening is driven by van der Waals forces and there is slippage at the interfacial boundaries between the moving particles and the matrix. The growth rate of the average radius of the particles, R , can be approximately expressed as\documentclass{article}\pagestyle{empty}\begin{document}$$\frac{{dR}}{{dt}} = \frac{{A\exp (- \sigma ^2)}}{{9\pi \eta \beta R^2 }}$$\end{document}where β is a function of the interfacial slippage length b, R , and the average surface distance between the particles h . The parameter b depends on the incompatibility and the degree of entanglement at the interface between the two polymers of the blend. The fact that the coarsening rate is decreased by the presence of a copolymer can be explained by a decrease in the value of b.