Influence of molecular structure of anionic polymer dispersants on dense silicon carbide suspension behavior and microstructures of green bodies prepared by slip casting

Abstract

This paper reports on the relationship between the molecular structure of polymer dispersants, the electrosteric interaction of dispersants on a solid surface, and the viscosity of a ceramic suspension. Ammonium polycarboxylate with a different hydrophilic to hydrophobic group ratio (m : n) was prepared and added to a dense silicon carbide slurry (35 vol%). The steric interaction and adsorbed structure of the dispersant on silicon carbide powder were examined by means of an atomic force microscope (AFM). An optimum hydrophilic to hydrophobic group ratio, which was obtained from the maximum repulsive force and the minimum viscosity of the suspension, was determined to be m : n = 10 : 90. Furthermore, the optimum suspension behavior for obtaining an uniform green body structure by slip casting was evaluated and discussed.