THE INFLUENCE OF SURFACE ENERGETICS OF CALCIUM-CARBONATE MINERALS ON MINERAL-POLYMER INTERACTION IN POLYOLEFIN COMPOSITES

Surface energetics of ground calcium carbonates (GCC), with or without stearic acid treatment, were determined by Inverse Gas Chromatography (IGC). The surface energy data were utilized as a predictive tool to explain the optimum coating level often needed on calcium carbonate mi nerals to obtain the desirable mechanical strength in filled polypropy lene composites. The dispersive components of the surface energies for the uncoated carbonates were also correlated with the corresponding i mpact resistance data. The surface with the highest energy was found t o be the least resistant while the least energetic mineral, on a compa rative scale, was the most resistant to impact. It is suggested that u nderstanding the surface energetics of finely-divided solids may be a key for the development of future mineral-filled polymer composites.