Early-strength polycarboxylate superplasticizer and preparation method thereof

The invention discloses an early-strength polycarboxylate superplasticizer and a preparation method thereof. The water reducer is prepared from raw materials in parts by weight as follows: 200 parts of unsaturated polyether, 10-30 parts of acrylic acid, 1-3 parts of an amide derivative, 0.1-0.5 parts of mohr's salt, 0.5-1.5 parts of a chain transfer agent, 0.2-0.8 parts of L-ascorbic acid, 0.8-4 parts of an oxidizing agent, 230 parts of deionized water and 12-20 parts of a 30% sodium hydroxide solution. The unsaturated polyether with a larger molecular weight is used, that is, a long side chain is introduced into a polycarboxylate superplasticizer molecule, quaternary amine and amide functional groups exist on a main chain, early hydration of hydration products, namely C3A and C3S, can be promoted, crystallization of Ca(OH)2 and forming of ettringite can be accelerated, the concrete setting time can be effectively shortened, the compactness of an early microstructure is improved, the early mechanical property of cement grout can be substantially improved, and the polycarboxylate superplasticizer promotes early-strength development of concrete and shows excellent early-strength performance from a macroscopic view.