Water-retaining shrinkage-reducing polycarboxylic acid water reducing agent and preparation method thereof

A technology of polycarboxylic acid and water retention, applied in the field of water reducing agent, can solve the problems of complex synthesis process and large increase in engineering cost

Active Publication Date: 2017-01-04

浙江红墙材料科技有限公司

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AI-Extracted Technical Summary

Problems solved by technology

[0026] Although the use of these shrinkage reducing agents reduces the shrinkage of concrete to a...

Abstract

The invention provides a water-retaining shrinkage-reducing polycarboxylic acid water reducing agent. The water-retaining shrinkage-reducing polycarboxylic acid water reducing agent can obviously increase the viscosity of a solution, delay the evaporation rate of water molecules and enhance the water retention property of the solution. Concrete shrinkage reducing test results show that the water-retaining shrinkage-reducing polycarboxylic acid water reducing agent has favorable shrinkage reducing effect; compared with common ether polycarboxylic acid water reducing agents from our company, the 28d shrinkage reducing rate ratio of concrete is lowered by 79%; and when the water-retaining shrinkage-reducing polycarboxylic acid water reducing agent is used for concrete, no influence is made to the workability and strength of the concrete, and the cost performance is high. The invention also provides a preparation method of the water-retaining shrinkage-reducing polycarboxylic acid water reducing agent. The method is simple, accessible in raw materials, low in cost and high in cost performance.

Technology Topic

EtherCost performance +6

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Examples

Experimental program(5)
Effect test(1)

Example Embodiment

[0079] Example 1

[0080] An embodiment of the preparation method of the water-retaining shrinkage-reducing polycarboxylic acid water-reducing agent of the present invention includes the following steps:

[0081] (1) In a closed autoclave, replace the air in the reactor with high-purity nitrogen repeatedly twice, inject 1 mol of propenol and 0.2 g of catalyst NaOH, raise the temperature of the reactor to 100-115°C, and start slowly adding 1 mol of ring Ethylene oxide, the reaction temperature is controlled within the range of 70℃, the pressure in the kettle is controlled at 0.2MPa, and the amount of ethylene oxide required for dripping is controlled by the reduction method. When the ethylene oxide dripping is completed, the temperature Control the temperature at 80°C and continue the reaction for 5 hours to obtain an intermediate product of the desired molecular weight.

[0082] (2) Keep the temperature at 80°C, start slowly adding 1 mol of glycidol dropwise, and control the dropwise addition within 1.5 hours. After the dropwise addition, continue the reaction for 4 hours, cool down, and discharge the material to obtain the polyhydroxy PEG macromonomer .

[0083] (3) In a glass four-necked flask equipped with a stirrer, a thermometer and a reflux condenser, add deionized water, 0.063mol isopropanol molecular weight regulator, 0.3mol polyhydroxy PEG macromonomer prepared in step (2) , 0.5mol APEG, 5mol acrylic acid, 0.5mol maleic anhydride, heated to 85℃, dripped an aqueous solution containing potassium persulfate initiator, the molar weight of the initiator was 0.0315mol, the dripping time was 2h, the dripping was completed After that, the reaction is kept for 4 hours, the temperature is lowered to 45°C, and the pH is adjusted to 7.0 with a 30% NaOH solution to obtain a water-retaining shrinkage-reducing polycarboxylic acid water-reducing agent.

Example Embodiment

[0084] Example 2

[0085] An embodiment of the preparation method of the water-retaining shrinkage-reducing polycarboxylic acid water-reducing agent of the present invention includes the following steps:

[0086] (1) In a closed autoclave, replace the air in the reactor with high-purity nitrogen 3 times, inject 1 mol of isopentenol and 0.5 gmol of catalyst KOH, heat the reactor to 110°C, and start slowly adding 40 mol of ring Ethylene oxide, the reaction temperature is controlled in the range of 115℃, the pressure in the kettle is controlled at 0.4MPa, and the amount of ethylene oxide required for dripping is controlled by the reduction method. When the ethylene oxide dripping is completed, the temperature Control it at 110°C and continue the reaction for 2 hours to obtain an intermediate product of the desired molecular weight.

[0087] (2) The temperature is lowered to 80°C, and 2 mol of glycidol is slowly added dropwise, and the dropwise addition is controlled for 2 hours. After the dropwise addition is completed, the reaction is continued for 5 hours, the temperature is lowered, and the material is discharged to obtain the polyhydroxy PEG macromonomer.

[0088] (3) In a glass four-necked flask equipped with a stirrer, a thermometer and a reflux condenser, add deionized water, 0.355 mol isopropanol molecular weight regulator, and 0.6 mol of the polyhydroxy PEG macromonomer prepared in step (2) , 1mol HPEG, 5mol methacrylic acid, 0.5mol itaconic acid, heated to 90°C, dripped an aqueous solution containing 0.12mol ammonium persulfate initiator, the molar weight of the initiator was 0.355mol, and the dripping time was 3h, After the dripping is completed, the reaction is kept for 2 hours, the temperature is lowered to 50°C, and the pH is adjusted to 6.0 with a 30% NaOH solution to obtain a water-retaining shrinkage-reducing polycarboxylic acid water reducing agent.

Example Embodiment

[0089] Example 3

[0090] An embodiment of the preparation method of the water-retaining shrinkage-reducing polycarboxylic acid water-reducing agent of the present invention includes the following steps:

[0091] (1) In a closed autoclave, replace the air in the reactor twice with high-purity nitrogen, inject 1 mol of methabutenol and 2 g of catalyst potassium carbonate, heat the reactor to 115°C, and start slowly adding 80 mol of ethylene oxide dropwise Control the reaction temperature in the range of 130℃, control the pressure in the kettle to 0.6MPa, and use the reduction method to control the amount of ethylene oxide required for dripping. When the ethylene oxide dripping is completed, control the temperature at At 120°C, the reaction was continued for 0.5h to obtain an intermediate product of the desired molecular weight.

[0092] (2) Lowering the temperature to 80°C, slowly adding 3 mol of glycidol, and controlling the dropping for 2 hours. After the dropping is completed, the reaction is continued for 6 hours, the temperature is lowered, and the material is discharged to obtain the polyhydroxy PEG macromonomer.

[0093] (3) In a glass four-necked flask equipped with a stirrer, a thermometer and a reflux condenser, add deionized water, 0.342 mol isopropanol molecular weight regulator, and 0.3 mol of the polyhydroxy PEG macromonomer prepared in step (2) , 1mol VPEG, 10mol acrylic acid, 0.1mol sodium allyl sulfonate, heated to 95°C, dripped an aqueous solution containing 0.05mol potassium persulfate initiator, the molar weight of the initiator was 0.342mol, and the dripping time was 2h After the dripping is completed, the temperature is kept for 3 hours, the temperature is lowered to 45°C, and the pH is adjusted to 6.5 with a 30% NaOH solution to obtain the water-retaining shrinkage-reducing polycarboxylic acid water reducing agent.

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