Method for preparing delayed coagulation type super plasticizer through atom transfer radical polymerization

Abstract

The invention relates to a method for preparing a delayed coagulation type super plasticizer through atom transfer radical polymerization. The method comprises the steps of with a delayed coagulationtype monomer and a carboxylic acid small monomer as main reaction raw materials, sequentially carrying out atom transfer radical polymerization (ATRP), alcoholysis and copolymerization so as to prepare the delayed coagulation type super plasticizer, namely that carrying out atom transfer radical polymerization (ATRP) on the delayed coagulation type monomer as a reactant under the system formed byan unsaturated initiator, transition metal halide and a ligand so as to obtain an unsaturated macromonomer, carrying out alcoholysis so as to obtain a delayed coagulation type macromonomer, and copolymerizing with the carboxylic acid small monomer, so as to obtain the delayed coagulation type super plasticizer. According to the method, a functional side chain consisting of delayed coagulation typestructural monomers is innovatively designed and synthesized by virtue of a controllable polymerization technical measure, a traditional polymer side chain structure is replaced, the super plasticizer presents excellent capacities of dispersing element purified slurry, and the coagulation time of the element purified slurry can be remarkably delayed, so that the later-period strength of concreteis improved, and multiple effects of high water reduction, slump resistance and delayed coagulation are achieved.

Description

technical field

[0001] The invention relates to the technical field of a retarding superplasticizer for cement concrete, in particular to a retarding macromonomer which is firstly subjected to atom transfer radical self-polymerization and alcoholysis by using a retarding monomer, and then A specific preparation method for copolymerizing with small carboxylic acid monomers to form retarded superplasticizers. Background technique

[0002] In recent years, with the rapid development of the construction industry, the amount of cement and concrete has been increasing. Since concrete admixtures can significantly improve the performance of concrete, they have become an indispensable and important component in the construction industry. At present, many concrete admixtures and cement have adaptability problems, such as the dispersion of concrete and instability of slump retention, which bring great inconvenience to specific engineering construction. In actual construction applicati...

Examples

Embodiment 1

[0027] First, 4.31g of vinyl acetate and 5.71g of vinyl butyrate were added to a reactor containing 86.09g of toluene, then 1.21g of allyl bromide, 4.31g of cuprous bromide, 6.85g of N,N,N,N,N -Pentamethyldivinyltriamine was added to it, and the reactor was filled with nitrogen in an ice-water bath for 3 times to remove oxygen for 30 minutes, then stirred for 18 minutes until it was evenly mixed, sealed under nitrogen protection, and continued to heat up to 30°C for polymerization , reacted for 50 hours, desalted and evaporated under reduced pressure to remove the solvent to obtain an unsaturated macromonomer; add the obtained unsaturated macromonomer to 12.82 g of methanol, stir and heat up to 60 ° C, and add 1.92 g of 50% Sodium hydroxide aqueous solution, alcoholysis for 30 minutes, after the alcoholysis is completed, the solvent and by-products are distilled off under reduced pressure to obtain a retarded macromonomer; finally, the retarded macromonomer is dissolved in 6.73...

Embodiment 2

[0029] After storing the retarded superplasticizer solution with a concentration of 20% by mass obtained in Example 1 at 6° C. for 15 days, its implementation effect was measured.

Embodiment 3

[0031] First, 50.06g of vinyl propionate was added to a reactor containing 400g of p-xylene, then 0.91g of methallyl chloride, 0.99g of cuprous chloride, 0.72g of cuprous bromide, 2.34g of 2,2-linked Pyridine was added to it, and the reactor was filled with nitrogen in an ice-water bath for 5 times to deoxygenate repeatedly for 25 minutes, then stirred for 30 minutes until it was mixed evenly, sealed under the protection of nitrogen, and continued to heat up to 50°C for polymerization reaction, reacted for 30 hours, desalted and reduced After pressure distillation to remove the solvent, the unsaturated macromonomer was obtained; the obtained unsaturated macromonomer was added to 103.66 g of ethanol, stirred and heated to 40 ° C, and 1.89 g of potassium hydroxide aqueous solution with a mass fraction of 20% was added, alcoholysed for 80 Minutes, after the alcoholysis is completed, the solvent and by-products are distilled off under reduced pressure to obtain a retarded macromono...

technical field

[0001] The invention relates to the technical field of a retarding superplasticizer for cement concrete, in particular to a retarding macromonomer which is firstly subjected to atom transfer radical self-polymerization and alcoholysis by using a retarding monomer, and then A specific preparation method for copolymerizing with small carboxylic acid monomers to form retarded superplasticizers. Background technique

[0002] In recent years, with the rapid development of the construction industry, the amount of cement and concrete has been increasing. Since concrete admixtures can significantly improve the performance of concrete, they have become an indispensable and important component in the construction industry. At present, many concrete admixtures and cement have adaptability problems, such as the dispersion of concrete and instability of slump retention, which bring great inconvenience to specific engineering construction. In actual construction applicati...

Examples

Embodiment 1

[0027] First, 4.31g of vinyl acetate and 5.71g of vinyl butyrate were added to a reactor containing 86.09g of toluene, then 1.21g of allyl bromide, 4.31g of cuprous bromide, 6.85g of N,N,N,N,N -Pentamethyldivinyltriamine was added to it, and the reactor was filled with nitrogen in an ice-water bath for 3 times to remove oxygen for 30 minutes, then stirred for 18 minutes until it was evenly mixed, sealed under nitrogen protection, and continued to heat up to 30°C for polymerization , reacted for 50 hours, desalted and evaporated under reduced pressure to remove the solvent to obtain an unsaturated macromonomer; add the obtained unsaturated macromonomer to 12.82 g of methanol, stir and heat up to 60 ° C, and add 1.92 g of 50% Sodium hydroxide aqueous solution, alcoholysis for 30 minutes, after the alcoholysis is completed, the solvent and by-products are distilled off under reduced pressure to obtain a retarded macromonomer; finally, the retarded macromonomer is dissolved in 6.73...

Embodiment 2

[0029] After storing the retarded superplasticizer solution with a concentration of 20% by mass obtained in Example 1 at 6° C. for 15 days, its implementation effect was measured.

Embodiment 3

[0031] First, 50.06g of vinyl propionate was added to a reactor containing 400g of p-xylene, then 0.91g of methallyl chloride, 0.99g of cuprous chloride, 0.72g of cuprous bromide, 2.34g of 2,2-linked Pyridine was added to it, and the reactor was filled with nitrogen in an ice-water bath for 5 times to deoxygenate repeatedly for 25 minutes, then stirred for 30 minutes until it was mixed evenly, sealed under the protection of nitrogen, and continued to heat up to 50°C for polymerization reaction, reacted for 30 hours, desalted and reduced After pressure distillation to remove the solvent, the unsaturated macromonomer was obtained; the obtained unsaturated macromonomer was added to 103.66 g of ethanol, stirred and heated to 40 ° C, and 1.89 g of potassium hydroxide aqueous solution with a mass fraction of 20% was added, alcoholysed for 80 Minutes, after the alcoholysis is completed, the solvent and by-products are distilled off under reduced pressure to obtain a retarded macromono...

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