The rheology of different proportions of low-density polyethylene (LDPE) and low-density polyethylene wax (LDWAX) without and with alumina was studied and correlated to a model. The viscosities of the polymer blend (LDPE + LDWAX) were studied for various compositions of LDWAX at different temperatures. The Arrhenius plot of logarithmic viscosity and reciprocal temperature for the polymer blends is linear. The enthalpy of viscous flow, determined from the slope of the Arrhenius Plot, varies linearly as a function of the average molecular weight. It is thus possible to predict the viscosity of any intermediate composition of the polymer blend. The viscosities of alumina-polymer blends (AP blend) with 50 vol% of alumina, prepared by solvent method, were also studied as a function of temperature, at a shear rate of 1333.33 s-1. The AP blends show a lower enthalpy of viscous flow compared to pure polymer blend because of the presence of stearic acid used as surfactant for alumina. The model developed in this study enables the prediction of viscosities of AP blends at any weight average molecular weight (Mw) of the main binder and temperature. © 2002 Kluwer Academic Publishers.