Der Einfluss einer Oberflächenbeschichtung von gefälltem Calciumcarbonat auf die mechanischen Eigenschaften von polymeren Nanocomposites

Precipitated calcium carbonate particles coated with stearin prepared in the aqueous medium were investigated in this work. The surface characterisation indicated that the adsorption of stearin onto the PCCs surface was controlled by a micelle-adsorption mechanism, which resulted in two types of coating layers with different chemicalphysical properties: a chemisorbed monolayer bonded directly with the PCC surface and one or more physisorbed stearate layers linked with the monolayer. More interestingly, the monolayer yielded by the water coating process showed a non-complete surface coverage. The surface energy of the coated PCC particles was also analysed in this research to find that stearin coating can effectively decrease the surface tension of the PCCs nanoparticles. HDPE/PCCs composites were prepared in this work, and the influence of the surface coating amount on the mechanical properties was discussed. Compared to the composites with pure PCCs, the impact toughness of the HDPE/PCCs increased as the surface stearin coating amount increased. The improved toughness of the composites filled by coated PCCs with respect to the uncoated PCCs was attributed to the weaker interfacial adhesion with the matrix and to the good dispersion of PCCs particles due to the stearin surface coating.