Modification of precipitated calcium carbonate to improve its activity toward elastomers

Surface area of precipitated calcium carbonate was modified by using difuncional compounds fe. : hydroxyacids, aminoacids, unsaturated acids, their derivatives and silanes. We observed the influence of the degree of surface coverage ratio of calcium carbonate on the proper-ties of modified filler, particularly its surface free energy. As a result of the modification, the dispersive component of surface energy and its specific interactions parameter S-f decreased. The investigations showed that the modification of calcium carbonate with difuncional compounds increased the adsorption of dibutyl phthalate on its surface. The activity of modified fillers in ethylene-propylene copolymer, butadiene-acrylonitrile copolymer and carboxylated butadiene-acrylonitrile copolymer was studied. We tried to modify CaCO3 by using hydroxyacids and proadhesive silanes substances so that interactions between fillers particles increased. As the result of these modifications the absorption of dibutyl plithalate increased what could indicate a higher tendency to create CaCO3 own structure.