Synthesis and Dispersive Properties of the Acrylic Acid-based Copolymer Dispersant

The copolymer dispersants were synthesized with acrylic acid, styrene sulfonic sodium and 3-hydroxypropyl acrylate as monomers through the orthogonal experiments.The molecular weights of dispersants were determined, and the best dispersant was chosen out based on the suspension rates of the granules.The influences of temperature, pH, NaCl concentration and dispersant concentration on the suspension rate of BaSO4 granules were studied with the best dispersant.Sedimentation speed of BaSO4 particles was determined as well as the dispersant adsorption.The adsorption increased with increasing copolymer concentration in a Langmuirian mode and reached a plateau at the concentration of 4 g/L.Size distribution of the particles was analyzed.The average particle size in the presence of the polymer was less than that in the absence of the polymer.Using synthesized dispersant, well-dispersed suspension of BaSO4 could be achieved.The suspension rate of BaSO4 granules was 99.18% with 0.4 g dispersant when pH and temperature were 7 and 20 ℃ respectively.At the same condition, the average diameter of BaSO4 particles was about 350 nm and the clear liquid volume above was only 2% after 6 h standing.