A kind of preparation method of high anti-mud type cement dispersant of esterification graft cationic side chain

Abstract

The invention discloses a preparation method for a cationic side chain esterified-grafted highly-mud-resistant cement dispersing agent, and belongs to the field of dispersing agents. The preparation method comprises the following steps: performing free radical polymerization on an unsaturated carboxylic acid monomer serving as a reactant to obtain a polycarboxylic acid main chain under the action of an initiator and a chain transfer agent, performing free radical polymerization on an unsaturated cationic quaternary ammonium salt monomer serving as a reactant to obtain a hydroxyl-terminated cationic side chain under an oxidization-reduction initiation system formed by high-valence ceric salt and alcohol, and performing esterification-grafting reaction on the polycarboxylic acid main chain, the hydroxyl-terminated cationic side chain and a polyethylene glycol compound in the presence of a catalyst. According to the preparation method, a process is simple and easy to control, and the preparation method is low in cost, energy-saving, efficient, environment-friendly and free of pollution; a composite side chain structure is modified and synthesized by a molecular structure design, so that side chain steric hindrance effects are successfully achieved, cationic charge arrangement is successfully implemented, water reduction and slump retaining characteristics and clay side effect suppression capabilities higher than those of an ordinary polycarboxylic acid water reducing agent are achieved, and the dispersing agent has broad market prospect and great popularization and application potential.

Description

technical field

[0001] The invention relates to the technical field of a high mud-resistant dispersant for cement concrete, in particular to a method of firstly polymerizing the polycarboxylic acid main chain and then polymerizing the cationic side chain by using unsaturated carboxylic acid monomers and then esterifying the main side chains for grafting The specific preparation method of the synthetic high anti-mud type cement dispersant. Background technique

[0002] With the rapid development of concrete science and engineering technology, cement concrete chemical admixtures that can significantly improve the performance of concrete workability and durability have received more and more attention and favor. However, concrete raw materials have an important impact on the application performance of chemical admixtures , especially a small amount of clay brought in when adding aggregates will have a negative impact on the fluidity, strength, and impermeability of concrete, wh...

Examples

Embodiment 1

[0027] First, 7.21g of acrylic acid, 8.65g of water, 0.91g of mercaptoacetic acid and 5.1g of ammonium persulfate with a mass fraction of 18% were added to the reactor, and the interval between each feeding was 9 minutes, and the temperature was raised to 75°C to carry out the polymerization reaction for 7 hours. , to obtain the polycarboxylic acid main chain aqueous solution; then add 12.89g trimethylallyl ammonium chloride, 1.41g n-butanol and 700.41g water in another reactor successively, and the reactor is filled with nitrogen and deoxygenated repeatedly 4 times for 15 After 10 minutes, seal it, add 0.52g of cerium ammonium nitrate, stir for 25 minutes until it is mixed evenly, continue to heat up to 35°C for polymerization reaction, and react for 12 hours to obtain an aqueous solution of hydroxyl-terminated cation side chains, and then add the obtained Polycarboxylic acid main chain aqueous solution and 50.4g methoxypolyethylene glycol (molecular weight = 2400), warming up...

Embodiment 2

[0029] After the cement dispersant solution with a concentration of 40% obtained in Example 1 was stored at 6° C. for 20 days, its implementation effect was measured.

Embodiment 3

[0031] First 7.83g of methacrylic acid, 1.18g of itaconic acid, 13.51g of water, 1.38g of mercaptopropionic acid and 12.29g of ammonium persulfate with a mass fraction of 22% were added to the reactor, and the temperature was raised to 55°C at intervals of 20 minutes each time. Polymerization reaction was carried out at ℃ for 8 hours to obtain an aqueous solution of polycarboxylic acid main chain; Water, the reactor was filled with nitrogen repeatedly 3 times to remove oxygen for 20 minutes, then sealed, added 5.37g of ammonium cerium sulfate, stirred for 18 minutes until it was mixed evenly, continued to heat up to 50°C for polymerization reaction, and reacted for 8 hours to obtain terminal hydroxyl cations side chain aqueous solution, then respectively add the obtained polycarboxylic acid main chain aqueous solution and 30g polyethylene glycol (molecular weight = 1200) in the reactor, heat up to 68 ° C, until the polyethylene glycol (molecular weight = 1200) is in a liquid st...

technical field

[0001] The invention relates to the technical field of a high mud-resistant dispersant for cement concrete, in particular to a method of firstly polymerizing the polycarboxylic acid main chain and then polymerizing the cationic side chain by using unsaturated carboxylic acid monomers and then esterifying the main side chains for grafting The specific preparation method of the synthetic high anti-mud type cement dispersant. Background technique

[0002] With the rapid development of concrete science and engineering technology, cement concrete chemical admixtures that can significantly improve the performance of concrete workability and durability have received more and more attention and favor. However, concrete raw materials have an important impact on the application performance of chemical admixtures , especially a small amount of clay brought in when adding aggregates will have a negative impact on the fluidity, strength, and impermeability of concrete, wh...

Examples

Embodiment 1

[0027] First, 7.21g of acrylic acid, 8.65g of water, 0.91g of mercaptoacetic acid and 5.1g of ammonium persulfate with a mass fraction of 18% were added to the reactor, and the interval between each feeding was 9 minutes, and the temperature was raised to 75°C to carry out the polymerization reaction for 7 hours. , to obtain the polycarboxylic acid main chain aqueous solution; then add 12.89g trimethylallyl ammonium chloride, 1.41g n-butanol and 700.41g water in another reactor successively, and the reactor is filled with nitrogen and deoxygenated repeatedly 4 times for 15 After 10 minutes, seal it, add 0.52g of cerium ammonium nitrate, stir for 25 minutes until it is mixed evenly, continue to heat up to 35°C for polymerization reaction, and react for 12 hours to obtain an aqueous solution of hydroxyl-terminated cation side chains, and then add the obtained Polycarboxylic acid main chain aqueous solution and 50.4g methoxypolyethylene glycol (molecular weight = 2400), warming up...

Embodiment 2

[0029] After the cement dispersant solution with a concentration of 40% obtained in Example 1 was stored at 6° C. for 20 days, its implementation effect was measured.

Embodiment 3

[0031] First 7.83g of methacrylic acid, 1.18g of itaconic acid, 13.51g of water, 1.38g of mercaptopropionic acid and 12.29g of ammonium persulfate with a mass fraction of 22% were added to the reactor, and the temperature was raised to 55°C at intervals of 20 minutes each time. Polymerization reaction was carried out at ℃ for 8 hours to obtain an aqueous solution of polycarboxylic acid main chain; Water, the reactor was filled with nitrogen repeatedly 3 times to remove oxygen for 20 minutes, then sealed, added 5.37g of ammonium cerium sulfate, stirred for 18 minutes until it was mixed evenly, continued to heat up to 50°C for polymerization reaction, and reacted for 8 hours to obtain terminal hydroxyl cations side chain aqueous solution, then respectively add the obtained polycarboxylic acid main chain aqueous solution and 30g polyethylene glycol (molecular weight = 1200) in the reactor, heat up to 68 ° C, until the polyethylene glycol (molecular weight = 1200) is in a liquid st...

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