Review Article

Measurement Techniques and Methods for the Pressure Coefficient of Viscosity of Polymer Melts

Table 3

Summary of pressure coefficients calculated from different methods.

Pressure coefficientFormulaAccuracyThermodynamic propertyRelationship

Nonlinear pressure profilesNot reliableNo
PVT
At constant shear rate Reliable
At constant shear stress Yes
Superposition
Zero shear rate