MICROCAPSULE TYPE POLYCARBOXYLATE SUPERPLASTICIZER AND PREPARATION METHOD THEREFOR

摘要

A microcapsule type polycarboxylate superplasticizer and a preparation method therefor. The microcapsule type polycarboxylate superplasticizer is a polycarboxylate aqueous solution encapsulated by a closed capsule; the closed capsule is an organic/inorganic composite shell layer made from a calcium ion gel of sodium alginate or gelatin and calcium carbonate; and the organic/inorganic composite shell layer is obtained by means of a diffusion-interface reaction of sodium alginate or gelatin with calcium salt and urea under the catalysis of urease. The microcapsule type polycarboxylate superplasticizer can meet the requirements of long-term and stable slump retention of concrete in some special projects at present. Steps of the preparation method are simple, no organic solvent is used, and the encapsulation efficiency is high. For the microcapsule type polycarboxylate superplasticizer, the protection and swelling functions of a capsule shell layer enables slow release of the polycarboxylate superplasticizer, thereby guaranteeing the adsorption performance in the later period, thus achieving the purpose of long-term and stable slump retention.