Preparation of polycarboxylic acid water reducing agent for prefabricated part

Abstract

The invention discloses a preparation method for a polyocarboxy acid water reducing agent for precast units, which belongs to the field of water reducing agent. Under the action of a persulphate initiator, methoxypolyethylene glycol acrylate, acrylic acid, unsaturated sulfonic acid or a salt monomer b thereof, unsaturated amide or a salt monomer c thereof are copolymerized in an aqueous solution; a terminator is used to process the rest initiator of the reaction at a later polymerization stage; and finally alkaline solution is used for neutralization and the water reducing agent is obtained. The methoxypolyethylene glycol with high polymerization degree is introduced as a grafting side chain, thereby making the prepared water reducing agent effectively shorten the concrete coagulation time without reducing the concrete initial fluidity and improving the concrete compression strength. The early strength type polyocarboxy acid high performance water reducing agent can be widely applied to the construction of various concrete projects with a low temperature or early strength requirements, in particular to the low energy consumption production process of precast concrete units. The water reducing agent has wide generalization space.

Description

technical field

[0001] The invention relates to the technical field of preparing a high-performance concrete water reducer, in particular to a specific preparation method of a polycarboxylate water reducer used for prefabricated components. Background technique

[0002] In recent years, with the rapid development of the domestic construction industry, not only the demand for high-performance concrete superplasticizers has increased year by year, but also the multi-faceted development of superplasticizer performance is required. my country's construction industry is in urgent need of high-quality polycarboxylate-based superplasticizers suitable for different construction environments, such as carboxylic acid series products with outstanding early-strength performance, which can greatly increase the early-stage strength of concrete and accelerate concrete production at lower temperatures in winter. Improve the construction progress and improve the efficiency of the construction...

Examples

Embodiment 1

[0030] Add 80g of methoxypolyethylene glycol with a molecular weight of M2000 to the reaction vessel equipped with a stirring, condensing, and effluent reflux device, and fully melt it at a temperature of 110°C. Add 0.14g of a polymerization inhibitor hydroquinone, and react for 15 minutes 2.88g of acrylic acid, 4.00g of concentrated sulfuric acid, and 16g of cyclohexane were added to the reaction vessel in sequence, kept at a constant temperature for 3.5 hours, and the cyclohexane was removed by vacuuming to obtain a mixture of methoxy polyethylene glycol acrylate and acrylic acid . During the second step of polymerization, the esterification reaction was added into a four-necked flask to obtain mixture a, 71.7 g of water was continuously stirred, and the temperature was raised to 50° C. in a water bath. Add 17.28g of acrylic acid, 22.1g of sodium methacrylate, and 80g of ammonium persulfate aqueous solution with a concentration of 1% into the reaction kettle at one time, rai...

Embodiment 2

[0032]Add 80g of methoxypolyethylene glycol with a molecular weight of M3000 to the reaction vessel equipped with a stirring, condensing, and effluent reflux device, and fully melt it at a temperature of 100°C. Add 0.01g of a polymerization inhibitor hydroquinone, and react for 10 minutes , then sequentially add 1.0g of acrylic acid, 0.06g of concentrated sulfuric acid, and 6.4g of cyclohexane into the reaction vessel, keep the temperature at constant temperature for 6.5 hours, and remove the cyclohexane by vacuuming to obtain a mixture of methoxy polyethylene glycol acrylate and acrylic acid a. During the second step of polymerization, the esterification reaction was added into a four-necked flask to obtain a mixture a, 128.5 g of water was continuously stirred, and the temperature was raised to 50°C by heating in a water bath. 2.1g of p-toluenesulfonic acid, 13.8g of AMPS, and 72.5g of ammonium persulfate mass aqueous solution with a concentration of 20% were added to the re...

Embodiment 3

[0034] To the device equipped with stirring, condensation, effluent reflux and Add 80g of methoxypolyethylene glycol with a molecular weight of M3000, fully melt, and add 0.23g of hydroquinone as a polymerization inhibitor at 140°C. After reacting for 13 minutes, add 5.76g of acrylic acid and 2.0g of p-toluenesulfonic acid in sequence. g. Add 24 g of cyclohexane into the reaction vessel, keep the temperature constant for 5 hours, remove the cyclohexane by vacuuming to obtain the mixture a of methoxypolyethylene glycol acrylate and acrylic acid. During the second step of polymerization, the esterification reaction was added into a four-necked flask to obtain mixture a, 108.5 g of water was continuously stirred, and the temperature was raised to 45°C by heating in a water bath. Add 29.4 g of sodium methacrylsulfonate, 11.2 g of N, N-methylene acrylamide, and 230 g of ammonium persulfate aqueous solution with a concentration of 20% into the reaction kettle at one time, raise the...

technical field

[0001] The invention relates to the technical field of preparing a high-performance concrete water reducer, in particular to a specific preparation method of a polycarboxylate water reducer used for prefabricated components. Background technique

[0002] In recent years, with the rapid development of the domestic construction industry, not only the demand for high-performance concrete superplasticizers has increased year by year, but also the multi-faceted development of superplasticizer performance is required. my country's construction industry is in urgent need of high-quality polycarboxylate-based superplasticizers suitable for different construction environments, such as carboxylic acid series products with outstanding early-strength performance, which can greatly increase the early-stage strength of concrete and accelerate concrete production at lower temperatures in winter. Improve the construction progress and improve the efficiency of the construction...

Examples

Embodiment 1

[0030] Add 80g of methoxypolyethylene glycol with a molecular weight of M2000 to the reaction vessel equipped with a stirring, condensing, and effluent reflux device, and fully melt it at a temperature of 110°C. Add 0.14g of a polymerization inhibitor hydroquinone, and react for 15 minutes 2.88g of acrylic acid, 4.00g of concentrated sulfuric acid, and 16g of cyclohexane were added to the reaction vessel in sequence, kept at a constant temperature for 3.5 hours, and the cyclohexane was removed by vacuuming to obtain a mixture of methoxy polyethylene glycol acrylate and acrylic acid . During the second step of polymerization, the esterification reaction was added into a four-necked flask to obtain mixture a, 71.7 g of water was continuously stirred, and the temperature was raised to 50° C. in a water bath. Add 17.28g of acrylic acid, 22.1g of sodium methacrylate, and 80g of ammonium persulfate aqueous solution with a concentration of 1% into the reaction kettle at one time, rai...

Embodiment 2

[0032]Add 80g of methoxypolyethylene glycol with a molecular weight of M3000 to the reaction vessel equipped with a stirring, condensing, and effluent reflux device, and fully melt it at a temperature of 100°C. Add 0.01g of a polymerization inhibitor hydroquinone, and react for 10 minutes , then sequentially add 1.0g of acrylic acid, 0.06g of concentrated sulfuric acid, and 6.4g of cyclohexane into the reaction vessel, keep the temperature at constant temperature for 6.5 hours, and remove the cyclohexane by vacuuming to obtain a mixture of methoxy polyethylene glycol acrylate and acrylic acid a. During the second step of polymerization, the esterification reaction was added into a four-necked flask to obtain a mixture a, 128.5 g of water was continuously stirred, and the temperature was raised to 50°C by heating in a water bath. 2.1g of p-toluenesulfonic acid, 13.8g of AMPS, and 72.5g of ammonium persulfate mass aqueous solution with a concentration of 20% were added to the re...

Embodiment 3

[0034] To the device equipped with stirring, condensation, effluent reflux and Add 80g of methoxypolyethylene glycol with a molecular weight of M3000, fully melt, and add 0.23g of hydroquinone as a polymerization inhibitor at 140°C. After reacting for 13 minutes, add 5.76g of acrylic acid and 2.0g of p-toluenesulfonic acid in sequence. g. Add 24 g of cyclohexane into the reaction vessel, keep the temperature constant for 5 hours, remove the cyclohexane by vacuuming to obtain the mixture a of methoxypolyethylene glycol acrylate and acrylic acid. During the second step of polymerization, the esterification reaction was added into a four-necked flask to obtain mixture a, 108.5 g of water was continuously stirred, and the temperature was raised to 45°C by heating in a water bath. Add 29.4 g of sodium methacrylsulfonate, 11.2 g of N, N-methylene acrylamide, and 230 g of ammonium persulfate aqueous solution with a concentration of 20% into the reaction kettle at one time, raise the...

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