ABSTRACT
Constitutive equations provide explicit relationships between dependent constitutive variables and independent constitutive variables. However, predictions can be obtained from a continuum analysis of transport only if values for the material parameters or coefficients in the constitutive equations are available. As was shown in Chapter 4, utilization of the entropy inequality can lead to inequality constraints for certain material parameters, and, sometimes, an explicit relationship between two material parameters can be derived. In general, however, actual values of the material parameters need to be determined from appropriate experiments or from molecular analyses. The emphasis in this chapter is on the use of molecular analyses to estimate binary mutual diffusion coefficients for rubbery polymer-solvent systems and for glassy polymer-solvent mixtures.
