In order to determine the adhesion of filler particles to polymeric matrix a set of tests on the tensile strength of composite materials based on CFD and PPS has been performed. The best results were observed for composites with nanosized amorphous fillers Mo and MoO2. The strength of composites filled with such fillers increased up to 2 times compared to the pure polymer value. The effect of using fine-ground mineral fillers is less – about 1.5 times. Coarse fractions of mineral fillers (50μm) do not have positive effect on the composite tensile strength. Thus, the effect of fillers on the mechanical properties of polymer-based composites depends heavily on the nature and dispersivity of the filler and is apparently determined by the behavior of chemical and mechanical bonds occurring on the phase boundaries. The large number of bonds for nanosized fillers is promoted by the high specific (to surface area) number of radicals on their surface, which results in strong bounding of particle to matrix, besides the polymeric material close to the phase boundary gains additional properties.

Since the size of nanoparticles is proportional to the thickness of interphase boundary layer, the considerable portion of the composite material transforms to a boundary interphase state, which properties, being different from both filler and polymer properties, determine the new characteristics of the composite material.