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A simple, accurate model for viscosities of polymer blends
Author(s) -
Carley James F.
Publication year - 1985
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760251605
Subject(s) - binary number , thermodynamics , mass fraction , mole fraction , materials science , viscosity , polymer , fraction (chemistry) , shear rate , simple (philosophy) , binary system , mathematics , mechanics , composite material , chemistry , chromatography , physics , philosophy , arithmetic , epistemology
The accurate but complex McAllister model for the melt viscosities (η) of binary polymer blends has been greatly simplified by dropping the terms involving only mole fraction and molecular weight, by switching from mole fraction to mass fraction, and by making the model explicit in dynamic, rather than kinematic, viscosity. The simpler Lecyar model was tested side‐by‐side with the McAllister in five binary systems and at seven levels of shear rate from 5 to 500 s −1 in each system. For the 35 pairs of curves fitted, the rms standard error of estimate was 0.0945 (In η), for the Lecyar model versus 0.0911 for the McAllister; the difference corresponds to only 0.4 percent additional error in the blend viscosity. Comparison of results in two systems, reported by Carley and Crossan (12) with those of other workers, indicate that the differences among what appear to be comparable, self‐consistent data sets are much greater than the within‐set errors of rheometric measurement and model fitting.