Preparation method for linear polycarboxylate type water reducing agent special for semi-hydrated gypsum

A technology of linear polycarboxylic acid and hemihydrate gypsum, which is applied in the field of building materials science, can solve the problems of inaccurate representation of molecular structure, poor adaptability, and large loss of fluidity of freshly mixed gypsum slurry over time, achieving excellent Water reduction and retarding effect, obvious dispersion effect and controllable setting time

Active Publication Date: 2014-03-26

CHINA UNIV OF MINING & TECH (BEIJING)

4 Cites 12 Cited by

AI-Extracted Technical Summary

Problems solved by technology

[0005] Due to the rapid hydration of building gypsum cementitious materials, the dispersion stability of traditional cement superplasticizers is poor, the fluidity of freshly mixed gypsum slurry is greatly lost over time, and the high ionic strength in gypsum cementitious material slurry will lead to polycarboxylic acid The spatial structure of the water reducing agent is compressed, the volume is reduced, and the steric hindrance effect is reduced, which greatly restricts the application of concrete water reducing agents in gypsum-based cementitious materials.

[0006] Patent CN101619120A discloses a sulfonated polycarboxylate ceramic water reducer and its preparation method, but there will be steric hindrance and selectivity, and th...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine

Abstract

The invention discloses a preparation method for a linear polycarboxylate type water reducing agent special for semi-hydrated gypsum. The preparation method comprises the following steps: a chain transfer agent is dissolved with water in a reactor at the temperature of 60-70 DEG C, the aqueous solution of X and the aqueous solution of an initiating agent are dropwise added into the reactor within 0.5-1 h, after the aqueous solution of the X and the aqueous solution of the initiating agent are dropwise added into the reactor completely, stirring is performed for reaction for 3-5 h, the temperature is dropped to be lower than 40 DEG C, and an alkaline solution is used for neutralization until the pH value ranges from 6 to 8, so that light yellow or sandy beige liquid namely the linear polycarboxylate type water reducing agent special for semi-hydrated gypsum is obtained, wherein the X comprises a monomer A, and can further comprise one or more of a monomer B, monomer C and a monomer D. The preparation method for the linear polycarboxylate type water reducing agent is simple in process and short in synthesis cycle, the water reducing agent is good in repeated stability, low in cost, non-toxic and pollution-free, does not contain formaldehyde, and is suitable for popularization and application, and the prepared water reducing agent product special for the semi-hydrated gypsum is high in water-reducing rate and excellent in stability, adaptability and delayed coagulation effect.

Technology Topic

GypsumChain transfer +7

Image

Examples

Experimental program(10)
Comparison scheme(2)
Effect test(1)

Example Embodiment

[0050] Example 1

[0051] To a 100 mL four-necked round bottom flask equipped with a thermometer, stirrer and bulb condenser was added 3.5 g of the chain transfer agent sodium methacrylate sulfonate and 10 g of deionized water. The temperature was raised to 60°C with stirring. After the sodium methacrylate was dissolved, the solution consisting of 9g acrylic acid, 3g vinyl acetate and 10g water and the solution consisting of 0.3g ammonium persulfate and 5g water were dripped within 1h with a peristaltic pump. Add to a four-neck bottle. After the dropwise addition, the reaction was stirred for 4h. After the reaction was completed, the temperature was lowered to below 40° C., and 30% sodium hydroxide was added to neutralize to pH 7 to obtain a pale yellow liquid. That is, the special linear polycarboxylate superplasticizer PC-1 for hemihydrate gypsum of the present invention.

Example Embodiment

[0052] Example 2

[0053] To a 100 mL four-necked round-bottomed flask equipped with a thermometer, stirrer and bulb condenser was added 4 g of the chain transfer agent sodium bisulfite and 10 g of deionized water. The temperature was raised to 70 °C with stirring. After the sodium bisulfite was dissolved, the solution consisting of 8 g of acrylic acid, 2 g of sodium p-styrene sulfonate and 10 g of water, and the solution of 0.8 g of potassium persulfate and 10 g of water were respectively mixed with a peristaltic pump for 0.5 h. Add dropwise to a four-necked bottle. After the dropwise addition, the reaction was stirred for 4h. After the reaction was completed, the temperature was lowered to below 40° C., and 30% sodium hydroxide was added to neutralize to pH 6 to obtain a brownish-yellow liquid. That is, the special linear polycarboxylate superplasticizer PC-2 for hemihydrate gypsum of the present invention.

Example Embodiment

[0054] Example 3

[0055] To a 100 mL four-necked round bottom flask equipped with a thermometer, stirrer and bulb condenser was added 2.1 g of the chain transfer agent sodium bisulfite and 10 g of deionized water. The temperature was raised to 70°C with stirring. After the sodium bisulfite was dissolved, a solution consisting of 10g acrylic acid, 4g sodium p-styrene phosphate, 1g hydroxyethyl acrylate and 10g water, 0.5g ammonium persulfate and 5g water were respectively formed by a peristaltic pump. The solution was added dropwise to the four-necked bottle within 0.5h. After the dropwise addition, the reaction was stirred for 3h. After the reaction was completed, the temperature was lowered to below 40° C., and 30% sodium hydroxide was added to neutralize to pH 6 to obtain a light brown liquid. That is, the special linear polycarboxylate superplasticizer PC-3 for hemihydrate gypsum of the present invention.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine

Login to view more

PUM

Description & Claims & Application Information

We can also present the details of the Description, Claims and Application information to help users get a comprehensive understanding of the technical details of the patent, such as background art, summary of invention, brief description of drawings, description of embodiments, and other original content. On the other hand, users can also determine the specific scope of protection of the technology through the list of claims; as well as understand the changes in the life cycle of the technology with the presentation of the patent timeline. Login to view more.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine

Login to view more

Classification and recommendation of technical efficacy words

Clear structure

Fault diagnosis and assessment method of intelligent substation

InactiveCN103001328AAccurate diagnosisClear structureCircuit arrangementsInformation technology support systemAssessment methodsSmart substation

Owner:SHANDONG UNIV

Silicon phthalocyanine compound and composite, their preparation and application thereof

ActiveCN1861603AStrong photosensitivityClear structureSilicon organic compoundsSilicon compound active ingredientsCompound sDisease

Owner:FUZHOU UNIVERSITY

Nitrogen-phosphorus codoped carbon loaded molybdenum carbide or tungsten carbide catalyst and preparing method and application thereof

ActiveCN107999108AClear structureControllable structureCatalyst activation/preparationElectrodesIonTungsten

Owner:CHINA UNIV OF PETROLEUM (EAST CHINA)

Active-active method for cloud data center management platforms

InactiveCN103812929AClear structureComplete layoutTransmissionInstrumentsVirtualizationData cloud

Owner:LANGCHAO ELECTRONIC INFORMATION IND CO LTD

Exoskeleton robot controlling system and method

InactiveCN103203748AClear structureReduce couplingProgramme-controlled manipulatorPID controllerMachine code

Owner:BUFFALO ROBOT TECH SUZHOU +1

Preparation method for linear polycarboxylate type water reducing agent special for semi-hydrated gypsum

AI-Extracted Technical Summary

Problems solved by technology

Abstract

Image

Examples

Example Embodiment

Example Embodiment

Example Embodiment

PUM

Description & Claims & Application Information

Similar technology patents

Preparation method of metal core-shell nanowire

Cordyceps cicadae rhzomorph as well as preparation method and application thereof

Multi-soaking condition simulation test model box and test method thereof

Battery pack active equalizing cascading structure

Experiment apparatus having certain pressure adsorption state by quantitative addition of moisture in coal body

Classification and recommendation of technical efficacy words

Fault diagnosis and assessment method of intelligent substation

Silicon phthalocyanine compound and composite, their preparation and application thereof

Nitrogen-phosphorus codoped carbon loaded molybdenum carbide or tungsten carbide catalyst and preparing method and application thereof

Active-active method for cloud data center management platforms

Exoskeleton robot controlling system and method