Abstract
The viscosities of 70mass% alumina suspensions retaining poly (acrylic ammonium) (PAN) or poly (30% methyl acrylate-70%acrylic ammonium) (PAM) were studied. The viscosities of suspensions retaining PAN showed two minima, the first at 0.60% PAN and the second at about 0.90%, and a maximum between the minima. This maximum viscosity moved to high content side of PAN and gradually decreased with an increase in milling time. While, the viscosities of suspensions retaining PAM showed only the first minimum. This difference between the viscosities of suspensions was explained, based on the different states of PAN and PAM adsorbed on the alumina particles.