Stabilization mechanism of main paint pigments

Polyacrylic acid sodium salt (NaPAA), a well-known dispersant, is generally used as a commercial dispersant in various paint formulations. Interaction of NaPAA with a group of minerals as single or mixture will be rather different. In the case of paint, as a variety of minerals and reagents are available in a mixture, in order to improve the paint formulation, this complex system should be revealed step by step. In the present study, the interaction of single minerals, titanium dioxide (TiO2), calcined kaolin (C.Kaolin), ground calcite (GCC) and their mixtures as TiO2 + GCC, TiO2 + C.Kaolin and TiO2 + GCC + C.Kaolin in the presence of NaPAA was investigated in terms of adsorption, rheology, and electrokinetic phenomena. The results showed that adsorption plateau, zeta potential and viscosity values of the mixtures were very close to the arithmetic mean of the individual minerals of the mixtures. The most attractive mineral ingredient for NaPAA was TiO2, followed by GCC and C.Kaolin. The mixture of minerals behaved differently at the same dosage of NaPAA compared to the single minerals. It is thus important to adjust the minerals mixtures and dispersant type and dosage to closely tune the paint properties. This study clearly revealed that it is more viable to adjust the desired paint properties using a mixture of minerals of different surface properties than a single mineral.