Amphibious Water-Soluble Copolymer. I. Its Synthesis and Dispersing Ability on Barium Titanate

An amphibious water-soluble copolymer, polyacrylamide/(α-N,N- dimethyl-N-acryloyloxyethyl) ammonium ethanate (PAAM/DAAE), was synthesized and used as a dispersion agent for BaTiO₃ particles. PAAM/DAAE was prepared from acrylamide and (α-N,N-dimethyl-N-acryloyloxyethyl) ammonium ethanate under basic conditions through a free-radical polymerization. The structure of this copolymer was verified with IR and ¹H-NMR spectra. The dispersing effects of PAAM/DAAE were examined through the measurement of the viscosity and sedimentation of BaTiO₃ suspensions and the green density. The results indicated that this copolymer could uniformly disperse the particles, reduce the viscosity, stabilize the suspensions, and produce high-density green compacts. In comparison with a commercial dispersant, the ammonium salt of poly(methylacrylic acid), PAAM/DAAE was clearly more effective.