Polyester monomer and preparation method thereof as well as polycarboxylate water reducing agent

Abstract

The invention discloses a polyester monomer and a preparation method thereof as well as a polycarboxylate water reducing agent and relates to the field of water reducing agents. According to the preparation method, an isocyanate compound with a linking group and multiple isocyanate groups is adopted as a reaction substrate, wherein the linking group comprises at least one cyclic structure. The polyester monomer adopting the cyclic structure is formed through reaction of at least two isocyanate groups of the isocyanate compound with an enol compound and polyglycol monoether respectively. As soil adopts a composite net layered structure, the size of the new cyclic structure of the polyester monomer is larger than that of the composite net layered structure of the soil. When the polycarboxylate water reducing agent synthesized from the polyester monomer adopting the cyclic structure encounters concrete containing soil, the cyclic structure of polyester monomer molecules can reduce or stop polycarboxylate water reducing agent molecules from being sucked into the soil, so that soil-resistant and water reducing effects are realized.

Description

technical field [0001] The invention relates to the field of water reducers, in particular to a polyester monomer, a preparation method thereof and a polycarboxylate water reducer. Background technique [0002] Polycarboxylate superplasticizer is currently the most commonly used type of high-efficiency water reducer. Compared with traditional naphthalene sulfonate formaldehyde condensation products and melamine formaldehyde condensation products, polycarboxylate superplasticizers have a higher permeability Low, good slump performance, low concrete shrinkage, strong adjustability in molecular structure and other advantages. [0003] In the prior art, polycarboxylate water reducers are usually obtained by polymerization of polyether monomers and unsaturated acid monomers as main components. Polyether monomer is a necessary monomer for the production of polyether-type polycarboxylate superplasticizer. When the polycarboxylate superplasticizer synthesized with it encounters con...

AI Technical Summary

Problems solved by technology

Polyether monomer is a necessary monomer for the production of polyether-type polycarboxylate superplasticizer. When the polycarboxylate superplasticizer synthesized with it encounters concrete with a lot of soil, the common problem is that the concrete has poor slump retention and the pump Delivery is difficult

However, in concrete with a lot of soil content, the soil first adsorbs the polycarboxylate superplasticizer, so that the amount of superplasticizer adsorbed on the cement particles is insufficient, the water reducing effect becomes worse, and the fluidity of the concrete becomes poor, reflecting that the concrete Short slump retention times make concrete difficult to pump

[0005] At present, the method to solve more soil in concrete is to add substances with amino groups to the synthetic polycarboxylate water reducer to improve the anti-soil effect, but the effect in practical application is not very ideal

Or solve the problem of more soil in concrete by adding too much polycarboxylate slump retaining agent, but at the same time there will be problems such as bleeding, and at the same time increase the cost of the concrete mixing plant

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