Synthesis method of side chain adsorption type concrete superplasticizer

Abstract

The invention relates to a synthesis method of a side chain adsorption type concrete superplasticizer, which uses unsaturated monomers, unsaturated initiators, transition metal complexes, small carboxylic acid monomers, etc. The method of graft copolymerization synthesizes the side chain adsorption type concrete superplasticizer, that is, the unsaturated monomer is used as the reactant, and the atom transfer radical polymerization ( ATRP) to obtain unsaturated macromonomers, and then hydrolyze the macromonomers to obtain anionic macromonomers, and then carry out free radical graft copolymerization reaction with small carboxylic acid monomers under the action of initiator and chain transfer agent to prepare have to. The process of the invention is controllable, the steps are simple, convenient, fast, energy-saving and environmentally friendly. Through the innovative design of the molecular structure, a side-chain adsorption concrete superplasticizer is synthesized, which realizes multiple functions such as excellent water reduction and slump protection, and suppression of side effects of clay. The variety of concrete superplasticizers has been enriched.

Description

technical field

[0001] The invention relates to the technical field of a superplasticizer for cement concrete, in particular to a superplasticizer that uses unsaturated monomers to self-polymerize and then hydrolyze to form anionic macromonomers, and then graft copolymerizes with carboxylic acid small monomers to form side plasticizers. The specific preparation method of the chain adsorption type concrete superplasticizer. Background technique

[0002] The deepening of urbanization and the rapid expansion of infrastructure have led to the rapid development of the construction industry. The amount of concrete and cement is increasing. As one of the important components of concrete, superplasticizers have become a hot spot in concrete research and development. The emergence of polycarboxylate superplasticizers with low dosage, high water-reducing rate and good slump retention has solved the problems of low water-reducing rate and retarded setting of ordinary lignosulfonate-bas...

Examples

Embodiment 1

[0026] First, add 5.05g of acrylic acid, 30.27g of water, and 63.11g of ethylamine into the reactor and mix well, then add 1.79g of ethyl 2-bromoacrylate, 3.8g of ferrous chloride, 10.37g of 1,1,4,7,10,10 - Hexamethyltriethylenetetramine, the reactor was filled with nitrogen in an ice-water bath and deoxygenated repeatedly 5 times for 25 minutes, then stirred for 15 minutes until it was mixed evenly, sealed under nitrogen protection, and continued to heat up to 70°C for polymerization reaction. After 20 hours, the unsaturated macromonomer was obtained after desalting and vacuum distillation to remove the solvent; the obtained unsaturated macromonomer was mixed with 32.4 g of water, the temperature was raised to 60 ° C, and 2.56 g of HCl aqueous solution with a mass fraction of 20% was added, Hydrolyze for 50 minutes, after the hydrolysis is completed, distill under reduced pressure to remove water and by-products to obtain anionic macromonomer; finally dissolve the anionic macr...

Embodiment 2

[0028] After the 30% side chain adsorption concrete superplasticizer solution obtained in Example 1 was stored at 5° C. for 30 days, its implementation effect was measured.

Embodiment 3

[0030] First, 200.22g of ethyl acrylate and 400.44g of dimethylformamide were added to the reactor and mixed evenly, then 1.49g of 1-bromo-3-methyl-2-butene, 1.44g of cuprous bromide, 2.6g of N,N ,N,N,N-Pentamethyldivinyltriamine, the reactor was filled with nitrogen in an ice-water bath and deoxygenated 3 times for 15 minutes, then stirred for 30 minutes until it was evenly mixed, sealed under nitrogen protection and continued to heat up to 10°C Polymerization reaction was carried out at 90°C for 48 hours, desalination and vacuum distillation to remove the solvent to obtain the unsaturated macromonomer; the obtained unsaturated macromonomer was mixed with 161.37g of water, the temperature was raised to 90°C, and 8g was added with a mass fraction of 30 % sodium hydroxide aqueous solution, hydrolyzed for 10 minutes, after the hydrolysis was completed, decompression distillation sloughed water and by-products to obtain anionic macromonomer; finally anionic macromonomer was dissol...

technical field

[0001] The invention relates to the technical field of a superplasticizer for cement concrete, in particular to a superplasticizer that uses unsaturated monomers to self-polymerize and then hydrolyze to form anionic macromonomers, and then graft copolymerizes with carboxylic acid small monomers to form side plasticizers. The specific preparation method of the chain adsorption type concrete superplasticizer. Background technique

[0002] The deepening of urbanization and the rapid expansion of infrastructure have led to the rapid development of the construction industry. The amount of concrete and cement is increasing. As one of the important components of concrete, superplasticizers have become a hot spot in concrete research and development. The emergence of polycarboxylate superplasticizers with low dosage, high water-reducing rate and good slump retention has solved the problems of low water-reducing rate and retarded setting of ordinary lignosulfonate-bas...

Examples

Embodiment 1

[0026] First, add 5.05g of acrylic acid, 30.27g of water, and 63.11g of ethylamine into the reactor and mix well, then add 1.79g of ethyl 2-bromoacrylate, 3.8g of ferrous chloride, 10.37g of 1,1,4,7,10,10 - Hexamethyltriethylenetetramine, the reactor was filled with nitrogen in an ice-water bath and deoxygenated repeatedly 5 times for 25 minutes, then stirred for 15 minutes until it was mixed evenly, sealed under nitrogen protection, and continued to heat up to 70°C for polymerization reaction. After 20 hours, the unsaturated macromonomer was obtained after desalting and vacuum distillation to remove the solvent; the obtained unsaturated macromonomer was mixed with 32.4 g of water, the temperature was raised to 60 ° C, and 2.56 g of HCl aqueous solution with a mass fraction of 20% was added, Hydrolyze for 50 minutes, after the hydrolysis is completed, distill under reduced pressure to remove water and by-products to obtain anionic macromonomer; finally dissolve the anionic macr...

Embodiment 2

[0028] After the 30% side chain adsorption concrete superplasticizer solution obtained in Example 1 was stored at 5° C. for 30 days, its implementation effect was measured.

Embodiment 3

[0030] First, 200.22g of ethyl acrylate and 400.44g of dimethylformamide were added to the reactor and mixed evenly, then 1.49g of 1-bromo-3-methyl-2-butene, 1.44g of cuprous bromide, 2.6g of N,N ,N,N,N-Pentamethyldivinyltriamine, the reactor was filled with nitrogen in an ice-water bath and deoxygenated 3 times for 15 minutes, then stirred for 30 minutes until it was evenly mixed, sealed under nitrogen protection and continued to heat up to 10°C Polymerization reaction was carried out at 90°C for 48 hours, desalination and vacuum distillation to remove the solvent to obtain the unsaturated macromonomer; the obtained unsaturated macromonomer was mixed with 161.37g of water, the temperature was raised to 90°C, and 8g was added with a mass fraction of 30 % sodium hydroxide aqueous solution, hydrolyzed for 10 minutes, after the hydrolysis was completed, decompression distillation sloughed water and by-products to obtain anionic macromonomer; finally anionic macromonomer was dissol...

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