Cationic polyacrylate emulsion and preparation method thereof

Abstract

The invention discloses a cationic polyacrylate emulsion and a preparation method thereof. The emulsion is prepared by using hydrogenated rosin, azo-bis-isobutyl hydrochloride, emulsifiers, cationic functional monomer, diacetone acrylamide, adipic dihydrazide, acrylic acid and esters, styrene and water as raw materials, and is synthesized by a clearance pre-emulsion polymerization process method;the cationic polyacrylate emulsion includes 45+ / - 1 percent of solid content, the pH value of 3-5, the viscosity of 190-220nm and the glass transition temperature of -7 DEG C. The preparation method comprises the following steps: a) raw materials preparation: preparing the raw materials in proportion; b) pre-emulsion preparation; c) seminal emulsion preparation; d) polymerization; e) post-adjustment. The glass transition temperature of the cationic polymer emulsion of the invention is -7 DEG C, which can notably improve the rigidity of cement, and greatly increase the impact resistance of CA mortar; moreover, the cationic polyacrylate emulsion has a stable air content at the same time, which ensures the freeze-thaw stability of the CA mortar. In addition, the cationic polyacrylate emulsion has the advantages of simple and convenient process requirements, and suitability for batch production.

Description

technical field [0001] The invention relates to a cationic polyacrylate emulsion and a preparation method thereof, which are mainly used for modifying high-speed railway CA mortar, and improving the fluidity, impact resistance and freeze-thaw stability of the mortar. Background technique [0002] Cationic acrylate emulsions refer to polymer or copolymer emulsions made of cationic surfactants or cationically charged acrylate monomers, the basic feature of which is that the surface of the latex particles or the polymer itself is positively charged. [0003] The main components of CA mortar used in high-speed railways are cement, sand, and emulsified asphalt. In order to ensure the stability of construction, most of the emulsified asphalt used is cationic emulsified asphalt, which has good stability in the cement system. After cationic emulsified asphalt is mixed with cement, etc., it can have proper stability, which not only ensures sufficient working time, but also guarantee...

AI Technical Summary

Problems solved by technology

However, because the above-mentioned acrylate emulsion only uses the combination of cationic emulsifier and nonionic emulsifier, the emulsifying ability of the cationic emulsifier itself is very weak, so it cannot significantly improve the fluidity of the mortar; in order to obtain a stable cationic acrylic acid Ester emulsion, that is, to obtain acrylic emulsion with good fluidity, a large amount of cationic emulsifier must be added, but a large amount of emulsifier will greatly affect the early strength of mortar

For the same reason, the air content is closely related to the type and amount of emulsifier. Only by ensuring a stable air content can there be good freeze-thaw stability. However, after adding a large amount of emulsifier, the stability of the air content can be guaranteed, but not Guarantee system early strength requirements

Therefore, it cannot improve the fluidity, impact resistance and freeze-thaw stability of CA mortar under the premise of ensuring strength.

And in its synthesis process, the direct drop method of monomer is adopted very early, it is difficult to achieve even drop of emulsifier and monomer according to the formula ratio, and it is quite difficult to produce batches of stable emulsions in industrial production. Big

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