Study of the effect of silicate fillers on the structural and rheological properties of acrylic dispersions

Abstract

This work reports the rheological properties of an acrylic aqueous dispersion filled with hollow aluminosilicate microspheres and highly dispersed amorphous silicon dioxide studied by using rotational viscometry. It was established that an increase in the degree of filling with hollow microspheres leads to a significant increase in the viscosity of the aqueous dispersion, which results in technological difficulties when applying coatings to the surface. The introduction of a small amount of silicon dioxide additive leads to a decrease in the structural strength and effective viscosity of the aqueous dispersion of the acrylic copolymer, which allows significantly reducing the viscosity and regulating the rheological characteristics of highly filled systems, which is decisive in the technology of their application. The combination of such fillers as silicon dioxide and hollow aluminosilicate microspheres in an aqueous dispersion of an acrylic copolymer allows simultaneously reaching a number of positive phenomena: a reduction in the viscosity of the material during application (without dilution) due to the use of high shear rates and an increase in the rate of dispersion structuring after application, and also allows achieving sedimentation resistance during storage and transportation.