Abstract
To investigate the effects of some high polymers on dispersion of barium sulfate particles, rheograms and sedimentation volumes of the suspensions containing sodium carboxymethylcellulose (Na-CMC), methylcellulose (MC) and polyvinylpyrrolidone (PVP) were measured. By the addition of Na-CMC to the suspension, a marked decrease of yield value and apparent viscosity were observed, though MC and PVP increase the apparent viscosity of the suspension. By the addition of 0.2% Na-CMC, the minimum viscosity in Newtonian flow was observed and further addition of Na-CMC increased the apparent viscosity again in pseudoplastic flow. The concentration (0.2% Na-CMC) was consistent well with the one at which the lowest sedimentation volume was attained. MC or PVP did not change the sedimentation volume of the suspension significantly. As the cause of good dispersion of the suspension in the case of Na-CMC, its adsorption on barium sulfate particles was assumed.
