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Influence of molecular weight distribution on the elasticity and processing properties of polypropylene melts
Author(s) -
Mieras H. J. M. A.,
Van Rijn C. F. H.
Publication year - 1969
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1969.070130204
Subject(s) - elasticity (physics) , polypropylene , polymer , materials science , molar mass distribution , thermodynamics , viscosity , composite material , shear rate , polymer chemistry , polymer science , physics
In a study of the flow behavior of polymer melts a semi‐empirical viscometric equation has been used which contains an elasticity parameter relating the shear dependence of the viscosity to the normal‐stress effect. The way in which both these effects are influenced by the molecular weight distribution of the polymers investigated is shown, and the influence of melt elasticity on polymer processing behavior is discussed. From previously published viscosity data the elasticity parameter has been determined for a number of polypropylene grades, and the possibility of classifying these grades according to a characteristic time constant is indicated.