Polycarboxylate superplasticizer and preparation method thereof

Abstract

The invention discloses a polycarboxylate superplasticizer and a preparation method thereof. The raw materials of the polycarboxylate superplasticizer comprise the following components in parts by weight: 190-200 parts of a polyether monomer, 15-25 parts of unsaturated acid, 1-5 parts of hydroxyl alkyl acrylate, 1.5-3.5 parts of an oxidizing agent, 1-3 parts of sodium hypophosphite, 0.5-2.5 parts of tartaric acid, 325 parts of water and 11-21 parts of 30-32% sodium hydroxide by mass concentration, wherein the polyether monomer is 600-3000 methylallyl polyoxyethylene-polyoxypropylene or isopentenol polyoxyethylene ether. The preparation method of the polycarboxylate superplasticizer, disclosed by the invention, is carried out in a temperature range of 5-40 DEG C and can be used for solving the problem that the initiating efficiency is relatively low at a relatively low temperature when a single reducing agent is used, meanwhile, the dropwise adding time can be shortened, the production cycle is shorter, the energy consumption is relatively low and the production cost is lowered.

Description

technical field [0001] The invention belongs to the technical field of chemical building materials, and in particular relates to a polycarboxylate water reducer and a preparation method thereof. Background technique [0002] Concrete water reducer is the most widely used concrete admixture, which can significantly improve the performance of concrete and is regarded as the fifth component of concrete. It has gone through three generations so far. The first generation is lignosulfonate ordinary water reducing agent, mainly using papermaking waste liquid cellulose as raw material, and the water reducing rate is lower, less than 10%; the second generation is mainly composed of β-naphthalenesulfonic acid formaldehyde condensate Naphthalene-based high-efficiency water-reducers are representative, and also include melamine-based water-reducers, sulfamic acid-based water-reducers and aliphatic high-efficiency water-reducers. The water-reducing rate can reach more than 20%. Cement ...

AI Technical Summary

Problems solved by technology

[0004] At this stage, some progress has been made in the preparation of polycarboxylate superplasticizers under low temperature (normal temperature), but in most normal temperature and heating processes, the chain transfer agents used are toxic thioglycolic acid and mercaptopropylene. These toxic chain transfer agents have a strong pungent odor, which may cause allergies and poisoning if inhaled, ingested, or absorbed through the skin, which not only makes the production environment worse, but also brings great safety hazards

CN102504124A uses modified polyether and acrylic acid as monomers, ammonium persulfate as an initiator, and sodium methacrylate sulfonate as a chain transfer agent to prepare an environmentally friendly polycarboxylate water reducer at 60±2°C, but the The water reducing agent is heated, which consumes a lot of energy

[0005] Based on the above-mentioned preparation method of water reducing agent, there are problems that the heating process has high requirements on equipment, high energy consumption, and high cost, and the use of toxic chain transfer agents is not environmentally friendly and has potential safety hazards.

Images