Synthetic amphoteric copolymer as a dispersant for aqueous barium titanate slurries

An amphoteric water-soluble copolymer I.e., poly(methacrylate-co-N-(4- vinylbenzyl)-N,N-dimethylglycinate) (PMV) was synthesized and used as a dispersion agent for barium titanate (BaTiO₃) (BT) particles. PMV was prepared from methacrylic acid and N-(4-vinylbenzyl)-N,Ndimethylglycinate in basic conditions through free radical polymerization. The structure of this copolymer was verified by its IR and ¹H-NMR spectra. The dispersing effects of PMV were examined and evaluated through viscosity and sedimentation measurements. The results indicate that this copolymer could uniformly disperse the particles, make the resulting suspensions less viscous and more stabilized. The dispersing ability of PMV is better than that of a commercial dispersant, ammonium polymethacrylate (PMAAN). Accordingly, the BT compacts with PMV exhibit higher dielectric constant values than those with PMAAN.