The mechanical properties of tablets compacted from blends are generally not directly predictable from the mechanical properties of the individual components. This paper introduces a structure-dependent fit, which gives a prediction of two major mechanical properties (elastic modulus and tensile strength) of compacts consisting of two particulate components. The structure-dependent fit takes into account the properties of the individual materials, macroscopic changes in the compact structure, and, if necessary, an interfacial interaction between particles of both components. Firstly, the relationship between the solid volume fraction and mechanical properties of compacts of single materials was fitted by the percolation theory. From these fits, the mechanical properties at zero porosity and the volume fraction of particles coupled in parallel were obtained. The material characteristics were applied into the structure-dependent fit to predict the maximal values (the upper boundary) and minimal values (the lower boundary) of the mechanical property of compacts made from the blends. It has been shown that the elastic modulus of the blends can be predicted by the upper boundary of the structure-dependent fit. The calculated tensile strengths result into a relative estimation of the adhesive interfacial interaction between particles of both components. In the end, all steps of the structure-dependent fit are included into a block diagram for the prediction of mechanical properties of compacts consisting of a blend. (C) 2004 Elsevier B.V. All rights reserved.
