An extension of compensation effect for zero shear melt viscosity to non-newtonian flow in glassy polymers

摘要

The structural parameters in the Arrhenius equation of zero-shear viscosity for various equilibrium polymer melts were compared with those obtained from the non-Newtonian viscosity for non-equilibrium flowing glasses of the same polymers. The comparison led us to the conclusion that the linear equation between the structural parameters (which is called compensation effect) for zero-shear melt viscosity holds also for the non-Newtonian flow in glassy polymers. The shear rate dependence of viscosity in polymer liquids was calculated using the extended linear equation of the structural parameters. Based on the calculation we suggest that the shear thinning behavior at higher shear rates is also possible due solely to the structural change independent of the disentanglement or scission of polymer chains. (C) 1998 Elsevier Science B.V. All rights reserved. [References: 19]