Dispersion of BaTi4O9 powders in aqueous solutions with PAMCOB copolymer

An anionic water-soluble copolymer, i.e., poly(acrylamide-co-4-carboxylamino-4-oxo-2-butenate) (PAMCOB) was used as a novel dispersant for aqueous BaTi4O9 (BT4) slurries. The dispersing property of this copolymer was examined by means of rheology, sedimentation, and leached Ba2+ concentration measurements. The dielectric properties of BT4 compacts were also measured. The results indicated that this copolymer can reduce the viscosity and stabilize the BT4 slurries. Compared to a commercial dispersant, ammonium salt of polymethylacrylic acid (PMAAN), PAMCOB was as effective in preparing stabilized suspensions. More importantly, PAMCOB reduced the leached Ba2+ concentration. Consequently, the BT4 compacts with this polymer showed higher dielectric constant and lower dielectric loss than those without any dispersant present.