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The status of non‐Newtonian polymer flow
Author(s) -
Porter Roger S.,
Johnson Julian F.
Publication year - 1963
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.760030105
Subject(s) - materials science , polymer , thermodynamics , amorphous solid , newtonian fluid , viscosity , flow (mathematics) , rheology , constant (computer programming) , molar mass distribution , mechanics , composite material , chemistry , crystallography , physics , computer science , programming language
This study summarizes the flow behavior of concentrated and melt systems of linear amorphous polymer. For low molecular weight polymer, viscosity increases regularly with a lower power dependence on molecular weight. This dependence decreases towards first power with increasing temperature but is independent of shear, with viscosities being constant up to the highest attainable steady state stresses, about 10 6 dynes/cm 2 . At a higher molecular weight, 2,000–40,000, depending on polymer type, the viscosity dependence on molecular weight changes abruptly to a high power which is generally about 3.4. Above the transition, this high power function is independent of temperature but depends markedly on shear. Non‐Newtonian flow sets in abruptly and predictably above the transitional molecular weight.