Preparation method of air-entraining ether polycarboxylate superplasticizer

Abstract

The invention discloses a preparation method of an air-entraining ether polycarboxylate superplasticizer. The preparation method comprises the following steps: (1) preparing an esterification product; (2) copolymerization reaction; and (3) neutralization reaction. According to the preparation method, the esterification product is prepared by esterification of coco fatty acid diethanolamide and unsaturated acid, the preparation method has the advantages of low cost and simplicity and convenience in operation, and the prepared esterification product participates in the next copolymerization reaction, so that a main chain of the polycarboxylate superplasticizer has hydrophilic groups such as amide and the like; the prepared polycarboxylate superplasticizer has good air entraining and foam stabilizing properties, and the workability and the strength of concrete are improved.

Description

technical field [0001] The invention belongs to the technical field of building admixtures, and in particular relates to a preparation method of an air-entraining ether polycarboxylate water reducer. Background technique [0002] With the construction of the country's large-scale infrastructure, nuclear power, water conservancy, bridges and various large-scale projects, the performance requirements of concrete are constantly improving, especially some major projects have strict requirements on the strength, durability and workability of concrete. High demands were made. [0003] Although the excellent water-reducing performance of polycarboxylate superplasticizers has been widely recognized by the industry, at present, due to the poor air-entraining effect of polycarboxylate superplasticizers, they are often used in concrete because of their high viscosity and low air-entrainment, resulting in the harmonization of concrete. The workability is poor, and the problem of diffic...

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Problems solved by technology

[0003] Although the excellent water-reducing performance of polycarboxylate superplasticizers has been widely recognized by the industry, at present, due to the poor air-entraining effect of polycarboxylate superplasticizers, they are often used in concrete because of their high viscosity and low air-entrainment, resulting in the harmonization of concrete. The workability is poor, and there is a problem of difficult pumping

[0004] At present, to solve the problem of poor air-entraining agent, compound air-entraining agent is often used to improve air-entraining performance, but the amount of air-entraining agent is small, and it is difficult to control in actual construction. If the amount is too large, the amount of air introduced into the concrete will be too large. If the amount is too small, its effect will be weak, and it will be difficult to improve the poor workability of concrete and affect the construction performance, resulting in little increase in the resistance of concrete to climate change and chemical erosion, which will affect the durability of concrete. The improvement is also slight

[0005] Patent CN 106380554A discloses a method for preparing an ester viscosity-reducing polycarboxylate water reducer. The publication date is February 08, 2017. It is prepared by esterification of polyethylene glycol monomethyl ether and methyl methacrylate Esterification product, the esterification product is polymerized with unsaturated sulfonic acid, cross-linking monomer, and cationic monomer under the action of emulsifier, initiator, and chain transfer agent. However, although the water reducer involved in this scheme has Good dispersibility, viscosity reduction and mud resistance, but not good air-entraining and foam-stabilizing properties

At present, there are few studies on air-entraining polycarboxylate superplasticizers, so it is important to develop an air-entraining ether-based polycarboxylate superplasticizer without the need to compound air-entraining agents, so as to directly improve the air-entraining performance of concrete. the meaning of

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