Preparation method of polycarboxylate water reducer containing polyether side chains

Abstract

The invention provides a preparation method of a polycarboxylate water reducer containing polyether side chains. The preparation method comprises the following steps: firstly, carrying out copolymerization on terminal alkenyl-containing alcohol and unsaturated carboxylic acid or anhydride to prepare a copolymer; and then carrying out oxyalkylation reaction on the obtained copolymer and epoxyalkane to obtain the polycarboxylate water reducer. The preparation method provided by the invention firstly prepares a main chain structure of the polycarboxylate water reducer through copolymerization and then forms the polyether side chains through oxyalkylation reaction. As the double bonds of a polymer monomer forming the main chain structure are not damaged, the double bond retention rate of the monomer is high, the polymerization effect is relatively good, and the viscosity of the obtained polycarboxylate water reducer is relatively high. The polycarboxylate water reducer prepared by the preparation method is obviously superior to that of a product prepared by the existing preparation method in concrete application performance. The preparation method provided by the invention is simple and convenient in process, mild in condition and strong in operability.

Description

technical field [0001] The invention relates to the field of high molecular polymers, in particular to a preparation method of a polycarboxylate water reducer containing polyether side chains. Background technique [0002] Polycarboxylate superplasticizer is a new type of concrete additive. It not only has a high concrete water reducing rate and good concrete fluidity, but the most important thing is that the fresh concrete mixed with polycarboxylate superplasticizer slumps The slump loss is small, the strength of the formed concrete is higher, the later drying shrinkage of the concrete is relatively small, and it has superior performance in various aspects such as corrosion resistance and aging resistance. At the same time, in the production process of polycarboxylate superplasticizer, its molecular structure has strong designability, and its molecular weight, molecular structure, type and arrangement of functional groups can be adjusted according to needs. The production p...

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Problems solved by technology

However, compared with the liquid polycarboxylate water reducer, the solid polycarboxylate water reducer currently on the market has a large gap in application performance, so the solid polycarboxylate water reducer has not yet completely replaced the liquid polycarboxylate water reducer. Liquid

[0004] The polycarboxylate water reducer containing polyether side chains is a common high-efficiency polycarboxylate water reducer. The conventional preparation process is to copolymerize macromonomers containing polyether chains and unsaturated carboxylic acid monomers. (such as Chinese patent CN 102140018A, etc.), in this preparation method, due to the high temperature in the production process of the polyether chain-containing macromonomer, the double bond component with polymerization activity in the monomer is greatly damaged, and its double bond The bond retention rate is only about 90%, which reduces the double bond content when participating in the synthesis of the water reducer, and reduces the molecular weight of the polycarboxylate water reducer, so that the obtained polycarboxylate water reducer product is also affected in terms of performance. affected

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