▎ 摘　　要

NOVELTY - Collapse-preserving early-strength functional monomer, is claimed. The functional monomer is mainly prepared by performing esterification modification of graphene oxide and hydroxycarboxylic acid, and then grafting a silane coupling agent. USE - The functional monomer is useful for collapse-preserving early-strength polycarboxylate water-reducing agent useful for preparing concrete. ADVANTAGE - The water-reducing agent: can ensures excellent water-reducing performance, and at same time, and makes concrete have excellent collapse-preserving performance and early-strength performance; and is simple to prepare. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: Preparing the collapse-preserving early-strength functional monomer comprising mixing the hydroxycarboxylic acid, graphene oxide, organic solvent and phosphomolybdic acid in first reaction vessel, heating, condensing and refluxing, removing the organic solvent, cooling, using saturated aqueous sodium bicarbonate solution and saturated aqueous sodium chloride solution to wash, filtering, and drying to obtain modified graphene oxide; adjusting the pH value of the ethanol aqueous solution, adding a silane coupling agent, pre-hydrolyzing in water bath, and adding modified graphene oxide; continuously heating the water bath, stirring, cooling to room temperature after the reaction, filtering, washing with ethanol aqueous solution, and drying. Collapse-preserving early-strength polycarboxylate water-reducing agent comprising polyether macromonomer, ethoxylated polypropylene glycol dimethacrylate, unsaturated acid, collapse-preserving early-strength functional monomer, unsaturated small monomer A and unsaturated small monomer B; the unsaturated small monomer A is unsaturated hydroxy ester; the unsaturated small monomer B is unsaturated amide or its derivatives.