THE USE OF SALTS OF D-METALS OF THE 4th PERIOD AS COAGULANTS IN THE PRODUCTION TECHNOLOGY OF EMULSION RUBBERS

Abstract

Currently, much attention is paid to improving the technology of rubbers obtained by emulsion polymerization. The stage of isolation of rubber from latex is one of the problematic stages of this production. The development of more advanced coagulating systems remains relevant. For the first time, the possibility of using d-metal salts of the fourth period of the periodic table of Mendeleev’s salts as coagulants in rubber isolation is considered: chloride of zinc, nickel and cobalt. The influence of the consumption of these salts on the completeness of rubber isolation is investigated, the properties of rubbers are estimated. It is found that zinc chloride has the best coagulating ability. The formation of insoluble complex compounds between the coagulating agent and surfactants of the latex system is established. It is revealed that the acidification of the coagulating system leads to the release of higher carboxylic acids in free form and the formation of sulfuric salts of zinc, cobalt and nickel, which remain in the aqueous phase (serum). The presence of these salts in the serum allows its usage in the technological process of emulsion rubbers production for the preparation of aqueous solutions of chlorides of these salts, as well as acidifying agent (sulfuric acid). The positive outcome of the considered issues contributes to the solution of a number of environmental problems. The studied rubber mixtures and vulcanizates prepared on the basis of experimental rubbers meet the regulatory requirements.