Thermorheological analysis of glass beads‐filled polymer melts

The complex viscosity of two thermoplastic polymer melts (high density polyethylene and polystyrene) filled with polydisperse glass beads (10–53 μm) has been studied in the domain of linear viscoelasticity as a function of frequency, temperature, and filler concentration. In the experimental windows examined, the complex viscosity can be well described by a new empirical model, which contains a Cross‐type viscosity model for the frequency dependence, a Quemada‐type model for the filler concentration dependence, and a compensation effect for the temperature dependence. This model allows the prediction of the complex viscosity of a glass bead‐filled thermoplastic melt provided only four parameters are known, namely: the average maximum packing volume fraction characteristic of the filler geometry and size distribution, the flow activation energy of the thermoplastic, the shear‐thinning parameter, and an adjustable parameter, also characteristic of the thermoplastic.