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A model for the zero shear viscosity
Author(s) -
Locati G.,
Pegoraro M.,
Nichetti D.
Publication year - 1999
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.11462
Subject(s) - dispersity , viscosity , quantum entanglement , monomer , materials science , polymer , thermodynamics , zero (linguistics) , shear viscosity , intrinsic viscosity , shear (geology) , range (aeronautics) , molecular dynamics , polymer chemistry , computational chemistry , physics , chemistry , composite material , quantum mechanics , linguistics , philosophy , quantum
Abstract An empirical equation for the number of entanglements per molecule has been proposed, which applies over all the molecular weight range. On this ground a simple equation for the zero shear viscosity of monodisperse polymer melts, η 0 , has been worked out that appears able to properly take into account the sharp transition of viscosity between the monomeric and the entanglement regimes. The molecular parameters appearing in the new viscosity equation are: the monomeric molecular weight m 0 , the monomeric friction factor ζ 0 , the molecular weight M, the average molecular weight between entanglements M e , and the entanglement friction factor ζ e 3.4 . This last parameter was evaluated for a number of monodisperse polymers.