Study Synthesis Of Polymeric Dispersant And Its Dispersion Performance

As people pay more attention on health and environmental protection, water-based paint is popular in architectural decoration. The water, as solvent, is non-toxic, innocuous and non-pollution, but it’s surface tension is much larger than that of the organic solvent. Therefore decreasing surface tension of water is needed. Polymer dispersant can reduce it. As a result, particles can be suspended stably with polymer dispersant in water.. Polymer dispersants are widely used in water-based paints.In this paper, polymer dispersants (polymethacrylic acid salts) were synthesized by radical aqueous solution polymerization. The dispersants’molecular weight was measured by Terminal Group Analysis. The effects of polymerization conditions on the molecular weight of polymethacrylic acid are investigated. The results show that the polymer dispersant is an efficient dispersing agent for titanium dioxide, which is synthesized with chain transfer agent concentration20%, initiator concentration0.5%, monomer concentration10%. The good results have been obtained with the molecular weight of polymethacrylic acid salt of about1000, The dispersion force of polymethacrylic acid salt is of about94%with its molecular weight of1000and concentration of0.2%.Effects of polymethacrylic acid neutralization on dispersivity were investigated. IR and SEM are employed for characterization.Polymethacrylic acid was neutralized with sodium hydroxide, ethanolamine and diethanolamine respectively. Effects of the neutralized dispersants on dispersion stability of titanium dioxide, iron red, carbon black are studied. The results show that the interactions between dispersant and pigment particles include not only simply physical adsorption but also chemical adsorption. Dispersed carbon black is no subsidence after60days.Sodium polymethacrylate show a perfect dispersal ability as it applied in emulsion paint.