Shrinkage-reducing polycarboxylic acid type superplasticize, preparation method and application thereof

A technology of superplasticizer and polycarboxylic acid series, which is applied in the field of preparation of shrinkage-reducing polycarboxylate series superplasticizer, can solve the problems of environmental pollution, non-compliance with environmental protection and energy saving modernization development, energy waste, etc., and achieve the preparation process Simple, excellent air-entraining effect, good enhancement effect

Inactive Publication Date: 2019-07-05
NORTHWEST A & F UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0008] CN200610040089.X discloses a shrinkage-reducing, crack-resistant graft copolymer concrete superplasticizer. When the dosage is 0.2%, the water-reducing rate reaches more than 25%, and the 28d drying shrinkage is 40-40% lower than that of naphthalene-based water-reducers. 50%, which is 30-50% lower than the benchmark concrete; however, the oily system used in the synthesis is easy to cause pollution, and it al

Method used

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  • Shrinkage-reducing polycarboxylic acid type superplasticize, preparation method and application thereof
  • Shrinkage-reducing polycarboxylic acid type superplasticize, preparation method and application thereof
  • Shrinkage-reducing polycarboxylic acid type superplasticize, preparation method and application thereof

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Experimental program
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Effect test

preparation example Construction

[0079] The preparation method of monomer C: the esterification reaction occurs directly by acrylic acid and the following (4) polyether at a molar ratio of 1:1.0 to 4.5 under solvent-free conditions, and under the conditions of adding a polymerization inhibitor and a catalyst;

[0080]

[0081] In formula (4), x and y are integers from 0 to 50 respectively, and R 1 It is an alkyl or hydroxyl group with 1 to 5 carbon atoms; EO represents ethylene oxide units, PO represents propylene oxide units, which can be linear or branched polymers, homopolymers, block copolymers, etc. These polyether groups are grafted into the copolymer to provide a certain dispersion ability and water retention performance, and at the same time provide a certain steric hindrance ability.

[0082] The aforementioned catalysts can be concentrated sulfuric acid, p-toluenesulfonic acid, phosphorous acid and solid superacids, etc. Lewis acids such as boron trifluoride, aluminum trichloride and iron sulfate...

Embodiment 1

[0110] Embodiment 1: superplasticizer preparation process

[0111] Monomer C preparation process:

[0112] In a 500ml glass reactor equipped with a thermometer, a stirrer, a nitrogen inlet tube and a reflux condenser, under the condition of no solvent, add an appropriate amount of polyether (the following formula, wherein x=23, y=0, R 1 is hydroxyl), the temperature is raised to 50°C, and after the polyether is completely melted, add acrylic acid (the molar ratio of acrylic acid to polyether is 3:1), polymerization inhibitor (hydroquinone, and hydroquinone accounts for 2% of the total mass of acrylic acid) and catalyst (concentrated sulfuric acid, and concentrated sulfuric acid accounts for 1.0% of the total mass of polyether), gradually warming up to 80-85 ° C and continuous reaction for 5h to obtain the crude product of monomer C, which can be directly Used in the synthesis of shrinkage-reducing polycarboxylate superplasticizers;

[0113]

[0114] Monomer D preparation ...

Embodiment 2

[0122] Embodiment 2: the concrete that mixes superplasticizer

[0123] The superplasticizer used in this example is the superplasticizer prepared in Example 1. Calculate the mass according to the solids in the superplasticizer:

[0124] In terms of mass percentage, cement 15.119%, sand 35.067%, 5-10mm pebbles 17.135%, 10-20mm pebbles 25.702%, water 6.929%, superplasticizer 0.048%; according to SL352-2006 "Hydraulic Concrete Test Regulations" Methods Coordinated mixing (slump controlled at 21±1cm), placed on a vibrating table and vibrated for 30s before forming, plastered before the initial setting of the concrete, removed the formwork after 24 hours, and sent it to the curing room for standard curing.

[0125] According to GB8076-2008 "Concrete Admixture" specification, the plasticizer meets the requirements of standard high-performance water reducer, and its performance indicators all meet the requirements of the specification. When the amount of superplasticizer is 0.32% o...

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Abstract

A shrinkage-reducing polycarboxylic acid type superplasticize, a preparation method and an application thereof are disclosed. Free radical copolymerization is performed on monomer A (5-50 parts), monomer B (1-60 parts), monomer C (20-100 parts), monomer D (10-60 parts) and monomer E (1-20 parts) in the presence of an initiator and a chain transfer agent, and finally a base is added to neutralize to adjust the PH to 7-8; wherein monomer A is acrylic acid, acrylic ester, acrylate or acrylic ester salt; monomer B is methacryl sulfonic acid or methacryl sulfonate; monomer C is a polyether monoacrylate or an alkoxy polyether monoacrylate; monomer D is maleic anhydride polyether ester, maleic anhydride hemi-ester, maleic anhydride polyether ester salt or maleic anhydride hemi-ester salt; monomerE is a copolymer of polysiloxane and acrylic acid modify polyether. The invention has features of wide source of raw materials, mature production technology, high water reduction rate, obvious enhancement effect, excellent air entrainment effect, good slump-retaining performance and anti-shrinkage and anti-drying crack.

Description

technical field [0001] The invention belongs to the technical field of concrete structure and concrete engineering, relates to the technical field of concrete admixture synthesis, and belongs to the technical field of synthesis of active organic monomers of polycarboxylic acid-based high-efficiency water reducers and the technical field of synthesis of polycarboxylic acid-based superplasticizers. It relates to a shrinkage-reducing polycarboxylate superplasticizer, a preparation method and an application thereof. Background technique [0002] In recent decades, concrete has developed into the most important contemporary structural engineering material. According to the data released by the National Bureau of Statistics, the national cement output in 2016 was 2.4 billion tons, a year-on-year increase of 2.5%. The cement and concrete consumed by its basic construction The consumption is in the leading position in the world. With the rapid advancement of urbanization in my coun...

Claims

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Application Information

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IPC IPC(8): C08F290/06C08F283/12C08F220/06C08F228/02C04B24/16C04B103/30
CPCC04B24/165C04B2103/32C08F283/128C08F290/062C08F220/06C08F228/02
Inventor 亢阳周敦宏于峰娄宗科
Owner NORTHWEST A & F UNIV
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