Abstract

Present paper represents hydrodynamic approach of describing the rheology of polymer suspensions filled with BaTiO₃ nanoparticles. It was found the shear thickening phenomenon at low shear rates with the subsequent shear thinning behavior under high shearing. The addition of various amounts of DBP has led to change in shape and size of the polymer molecule influencing the flow type, flocculation processes and strength of initial microstructure. Shear thickening is caused by elastic deformation of structural bonds «polymer-polymer» in the initial microstructure. Thus, pseudoplasticity indicates high strength and incomplete plasticization; exceptional thixotropy shows excessive plasticizing effect of DBP because of too straightened polymer molecules. The destruction of intramolecular bonds under external forces caused formation of additional molecular entanglements and additional flocculation of unbounded nanoparticles. In turn, the instant transition from rheopexy to thixotropy has occurred at constant hydrodynamic radius of structural elements due to full flocculation of BaTiO₃ nanoparticles with polymer molecules providing better printability.

Keywords: Rheology; Shear thickening; Rheopexy; Pseudoplasticity; Thixotropy