An organic phosphonate retarder, its preparation method and application

Abstract

An organic phosphonate retarder, its preparation method and application relate to the technical field of concrete admixtures. The specific preparation method is as follows: Add a hydroxylamine monomer, water, phosphorous acid, and a catalyst into a reaction vessel, dropwise add formaldehyde for reaction, cool the reaction to room temperature, and add liquid alkali to neutralize to a pH of 5 to obtain the organic phosphonate retarder. The hydroxylamine monomer is an organic compound containing both an amino group and a hydroxyl group in its molecular structure. The molar ratio of the active hydrogen in the amino group of the hydroxylamine monomer to phosphorous acid is 1:0.5 - 1, the molar ratio of phosphorous acid to formaldehyde is 1:1 - 1.2, the catalyst accounts for 3 - 10% of the total mass, and the mass of water accounts for 30 - 50% of the total mass. The organic phosphonate retarder prepared by the present invention has both phosphonic acid groups and hydroxyl groups, can simultaneously complex calcium ions in the cement solution to delay the formation of hydration products, and can form a solvation film on the cement particles to hinder the hydration of cement, with a stronger retardation effect.

Description

Technical Field

[0001] The present invention relates to the technical field of concrete admixtures, and particularly relates to an organic phosphonate retarder, a preparation method thereof, and an application thereof. Background Art

[0002] As a new generation of high-performance water reducer, polycarboxylate water reducer is widely used in the field of engineering construction due to its advantages such as low dosage, high water reduction rate, adjustable molecular structure, and environmental friendliness, and has become the most important product in the field of concrete admixtures. However, when applied to ordinary commercial concrete projects, polycarboxylate water reducers also expose some special problems of their own, such as the adaptability to cement, the sensitivity to the mud content of aggregates, and the influence of external temperature changes. In actual engineering applications, it is often necessary to be used in combination with other types of admixtures. The compound use of a retarder and a high-performance water reducer can extend the setting time of concrete and reduce the slump loss, which is a reliable method to ensure the transportation of ready-mixed concrete, normal construction, and concrete quality.

[0003] Retarders mainly achieve the purpose of extending the setting time of concrete and maintaining the plasticity of fresh concrete for a long time by reducing the hydration rate of cement and the heat of cement hydration. In summer concrete construction, due to hot weather, rapid water evaporation, and fast cement hydration, it is easy to cause large slump loss of concrete. Adding an appropriate amount of retarder can improve the slump retention performance of concrete and the construction performance of concrete; in the construction of mass concrete, adding a retarder can delay the heat release of cement hydration, delay the appearance time of the hydration heat peak, reduce the temperature stress, and is beneficial to improving the crack resistance of concrete. Commonly used concrete retarders can be divided into inorganic retarders and organic retarders according to their chemical compositions. Commonly used inorganic retarders include phosphates, metaphosphates, borax, sodium fluorosilicate, etc. Organic retarders include hydroxycarboxylic acids, amino carboxylic acids and their salts, polyols and their derivatives, sugars, etc.

[0004] Chinese Patent No. CN 116253832 B discloses a polymer for ultra-high temperature retarder, a preparation method thereof, and an ultra-high temperature retarder. The polymer structure has a high-temperature resistant and strongly adsorbing cationic monomer, a polycarboxyl monomer, and a high-temperature resistant rigid monomer with a special configuration. As an ultra-high temperature retarder, the applicable temperature range of this compound is 50 - 240 °C or above. When the addition amount in the cement slurry for well cementing is 4.0%, the thickening time of the cement slurry can reach 546 min, and the thickening time has a good linear relationship with temperature and addition amount. However, it has the problems of too high retarder dosage and limited retardation effect.

[0005] The Chinese patent application for invention with the publication number CN 113999341 A discloses a composition for preparing a retarder and a retarder. A retarder is prepared with water, a stabilizer, itaconic acid, acrylic acid, 2-acrylamido-2-methylpropanesulfonic acid, a silane coupling agent, an alkaline substance and an initiator. This retarder has good temperature resistance and can meet the requirements of 60 - 130 °C. Moreover, the addition amount of the retarder has a good linear relationship, does not affect the strength of the cement stone, and has good compatibility with other additives of oil well cement. However, it belongs to polymer materials, the proportion of retardation groups is relatively small, the retardation effect is poor, and the incorporation amount of the retarder is high.

[0006] The Chinese invention patent with the announcement number CN 107188451 B discloses a long-acting retarder and its preparation method. An esterification reaction is carried out with a hydroxycarboxylic acid retarder and a polyol retarder to obtain a retarder. The retarder of the obtained product will be delayed until the middle and late stages of the concrete setting process to release, obtaining a long-acting retarder. However, the retardation performance of this retarder is unstable. To ensure the retardation effect, it is also necessary to use a phosphate retarder in compounding.

[0007] The Chinese patent with the announcement number CN 111848978 B discloses a modified bagasse retarder and its preparation method. The specific method is as follows: First, bagasse is pretreated with sulfite or chlorite to remove lignin and part of hemicellulose in the bagasse; then it is acid-hydrolyzed with a composite acid under catalytic conditions. The prepared retarder contains not only hydroxyl groups and carboxyl groups but also functional groups such as phosphoric acid groups. The retardation effect of the modified bagasse retarder is better than that of sodium gluconate under both normal temperature (20 °C) and high temperature (50 °C) conditions, and it has no influence on the later strength of concrete. However, the reaction process is relatively complex. Due to the presence of water in the reaction system during the acid-catalysis process, the esterification efficiency is low, and it is difficult for the acid to graft onto the sucrose molecule. Summary of the Invention

[0008] Technical problems to be solved: Aiming at the technical problems of low retardation efficiency and sensitivity to the incorporation amount of retarder existing in the prior art, the present invention provides an organic phosphonate retarder, its preparation method and application, which are obtained by reacting a hydroxylamine monomer with phosphorous acid and formaldehyde under a catalyst. The prepared organic phosphonate retarder has both phosphonic acid groups and hydroxyl groups, can simultaneously complex calcium ions in the cement solution to delay the formation of hydration products and can form a solvation film on the cement particles to hinder the hydration of cement, and has a stronger retardation effect.

[0009] Technical solution: The first object of the present invention is to provide a preparation method of an organic phosphonate retarder, which is specifically as follows: Add a hydroxylamine monomer, water, phosphorous acid, and a catalyst into a dry reaction vessel, dropwise add formaldehyde at a temperature of 100-130 °C for reaction, cool to room temperature after reacting for 4-12 h, and add liquid alkali to neutralize to pH 5 to obtain the organic phosphonate retarder. The hydroxylamine monomer is an organic compound containing both an amino group and a hydroxyl group in its molecular structure. The molar ratio of the active hydrogen in the amino group of the hydroxylamine monomer to phosphorous acid is 1:0.5-1, the molar ratio of phosphorous acid to formaldehyde is 1:1-1.2, the catalyst accounts for 3-10% of the total mass, and the mass of water accounts for 30-50% of the total mass (so that the hydroxylamine monomer and phosphorous acid can be better dissolved).

[0010] Preferably, the hydroxylamine monomer is monoethanolamine, isopropanolamine, isobutanolamine, L-valinol, p-aminobenzyl alcohol, serinol, aminobutanetriol, 1,3-diamino-2-propanol, glucosamine, glucomethylamine, glucoethylamine, glucosamine hydrochloride or glucosamine sulfate.

[0011] Preferably, the catalyst is concentrated sulfuric acid, phosphoric acid or p-toluenesulfonic acid.

[0012] Preferably, the liquid alkali is an aqueous sodium hydroxide solution with a mass fraction of 30%.

[0013] The second object of the present invention is to provide an organic phosphonate retarder prepared by the above method.

[0014] The third object of the present invention is to provide an application of an organic phosphonate retarder as a retarder for cement-based materials.

[0015] Preferably, the dosage of the organic phosphonate retarder is 0.1‰-0.5‰ of the mass of the gel material.

[0016] Preferably, the gel material is cement and admixtures. In addition to pure cement, admixtures such as fly ash and slag powder can also be mixed.

[0017] The retardation mechanism of phosphate-based retarders is that phosphates adsorb and complex with calcium ions in the cement paste, hindering the formation of hydration products; while polyols and sugar-based retarders mainly produce a thin film through adsorption on the surface of cement particles, covering the surface of cement particles and hindering the hydration of the cement paste. The present invention introduces a phosphonic acid group into a polyhydroxy compound to synthesize a retarder containing both a hydroxyl group and a phosphonic acid group, which can not only complex calcium ions in the cement paste through the phosphonic acid group to inhibit the formation of hydration products, but also adsorb on the surface of cement particles to form a thin film, hindering the hydration of cement particles. With the synergistic effect of the two retardation mechanisms, the obtained retarder has a stronger retardation effect. Prepare retarders with ultra-long retardation time and controllable time (high dosage of retarder, long retardation time, low dosage, short retardation time).

[0018] Beneficial effects: In the present invention, phosphorous acid is grafted onto a polyhydroxy compound through the Mannich reaction of the amino group in the hydroxylamine monomer and phosphorous acid, generating an organic phosphonate retarder containing both hydroxyl and phosphonic acid groups. This reaction has simple and easy-to-operate conditions, and the obtained retarder has stable structural properties. Due to the strong complexation and adsorption ability of the phosphonic acid group, it can complex calcium ions in the pore solution of cement, inhibiting the formation of hydration products. At the same time, it can also adsorb on the cement particles to form a solvation film, hindering the hydration of cement. Therefore, the organic phosphonate retarder of the present invention has stronger retardation performance compared with other retarders. At a dosage of 0.015%, this retarder can extend the initial setting time of cement paste by more than 2.5 hours compared with sodium gluconate. Specific embodiments

[0019] To better understand the present invention, the content of the present invention will be further clarified below in conjunction with embodiments, but the content of the present invention is not limited only to the following embodiments. Any equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the protection scope of the present invention.

[0020] The cement used is Helin 42.5R.P.O. The sand is standard sand. The tests for the fluidity of cement paste and mortar are carried out with reference to the standard of GB / T8077 - 2000, and the setting time of cement paste is tested according to GB / T 1346—2011.

[0021] The raw materials used in the embodiments of this specification are sourced as follows:

[0022] Phosphorous acid, AR, 99%;

[0023] Concentrated sulfuric acid, AR, 98%;

[0024] p-Toluenesulfonic acid, AR, 99%;

[0025] Phosphoric acid, AR, 85%;

[0026] Monoethanolamine, AR, 99%;

[0027] Isobutanolamine, AR, 95%;

[0028] L-Valinol, AR, 97%;

[0029] p-Aminobenzyl alcohol, AR, 98%;

[0030] Serinol, AR, 98%;

[0031] Aminobutanetriol, AR, 99%;

[0032] 1,3-Diamino-2-propanol, AR, 97%;

[0033] Glucosamine, AR, 98%;

[0034] N-Methyl-D-glucamine, AR, 98%;

[0035] N-Ethyl-D-glucamine, AR, 98%;

[0036] Glucosamine hydrochloride, AR, 97%;

[0037] Glucosamine sulfate, AR, 98%;

[0038] Sodium gluconate TNa in the comparative example, AR, 99%;

[0039] n-Propylamine, AR, 98%;

[0040] Ethylenediamine, AR, 98%. All of the above were purchased from Sinopharm Chemical Reagent Co., Ltd.

[0041] Example 1

[0042] Add 16.4 g of phosphorous acid, 2.77 g of sulfuric acid, and 16.6 g of water to a dry 250 mL three-necked flask. Start stirring, and add 6.11 g of monoethanolamine dropwise. After the addition is complete, heat to 120 °C and add 16.23 g of formaldehyde dropwise. After the addition is complete, continue the reaction at 120 °C for 6 h. Cool to room temperature and then add liquid alkali to neutralize to pH 5.0 to obtain the organic phosphonate retarder HN-1.

[0043] Example 2

[0044] Add 16.4 g of phosphorous acid, 4.94 g of sulfuric acid, and 18.5 g of water to a dry 250 mL three-necked flask. Start stirring, and add 8.91 g of isobutanolamine dropwise. After the addition is complete, heat to 110 °C and add 17.86 g of formaldehyde dropwise. After the addition is complete, continue the reaction at 110 °C for 8 h. Cool to room temperature and then add liquid alkali to neutralize to pH 5.0 to obtain the organic phosphonate retarder HN-2.

[0045] Example 3

[0046] Add 16.4 g of phosphorous acid, 1.91 g of sulfuric acid, and 19.1 g of water to a dry 250 mL three-necked flask. Start stirring, and add 10.32 g of L-valinol dropwise. After the addition is complete, heat to 100 °C and add 17.86 g of formaldehyde dropwise. After the addition is complete, continue the reaction at 100 °C for 10 h. Cool to room temperature and then add liquid alkali to neutralize to pH 5.0 to obtain the organic phosphonate retarder HN-3.

[0047] Example 4

[0048] In a dry 250 mL three-necked flask, add 13.12 g of phosphorous acid, 2.93 g of sulfuric acid, and 17.58 g of water. Start stirring, and add dropwise 12.32 g of p-aminobenzyl alcohol. After the addition is complete, heat to 130 °C and add dropwise 15.58 g of formaldehyde. After the addition is complete, continue the reaction at 130 °C for 4 h. Cool to room temperature and then add liquid alkali to neutralize to pH 5.0 to obtain the organic phosphonate retarder HN-4.

[0049] Example 5

[0050] In a dry 250 mL three-necked flask, add 16.4 g of phosphorous acid, 3.10 g of sulfuric acid, and 18.6 g of water. Start stirring, and add dropwise 9.11 g of serinol. After the addition is complete, heat to 120 °C and add dropwise 17.86 g of formaldehyde. After the addition is complete, continue the reaction at 120 °C for 5 h. Cool to room temperature and then add liquid alkali to neutralize to pH 5.0 to obtain the organic phosphonate retarder HN-5.

[0051] Example 6

[0052] In a dry 250 mL three-necked flask, add 16.4 g of phosphorous acid, 6.39 g of sulfuric acid, and 19.18 g of water. Start stirring, and add dropwise 12.11 g of tromethamine. After the addition is complete, heat to 120 °C and add dropwise 16.23 g of formaldehyde. After the addition is complete, continue the reaction at 120 °C for 6 h. Cool to room temperature and then add liquid alkali to neutralize to pH 5.0 to obtain the organic phosphonate retarder HN-6.

[0053] Example 7

[0054] In a dry 250 mL three-necked flask, add 16.4 g of phosphorous acid, 3.21 g of sulfuric acid, and 19.24 g of water. Start stirring, and add dropwise 9.01 g of 1,3-diamino-2-propanol. After the addition is complete, heat to 110 °C and add dropwise 19.48 g of formaldehyde. After the addition is complete, continue the reaction at 110 °C for 7 h. Cool to room temperature and then add liquid alkali to neutralize to pH 5.0 to obtain the organic phosphonate retarder HN-7.

[0055] Example 8

[0056] In a dry 250 mL three-necked flask, add 16.4 g of phosphorous acid, 3.61 g of phosphoric acid, and 21.7 g of water. Start stirring, and add dropwise 17.92 g of glucosamine. After the addition is complete, heat to 100 °C and add dropwise 16.23 g of formaldehyde. After the addition is complete, continue the reaction at 100 °C for 9 h. Cool to room temperature and then add liquid alkali to neutralize to pH 5.0 to obtain the organic phosphonate retarder HN-8.

[0057] Example 9

[0058] In a dry 250 mL three-necked flask, add 16.4 g of phosphorous acid, 2.23 g of phosphoric acid, and 22.4 g of water. Start stirring and add 19.52 g of meglumine dropwise. After the addition is complete, heat to 100 °C and add 16.23 g of formaldehyde dropwise. After the addition is complete, continue the reaction at 100 °C for 10 h. After cooling to room temperature, add liquid alkali to neutralize to pH 5.0 to obtain the organic phosphonate retarder HN-9.

[0059] Example 10

[0060] In a dry 250 mL three-necked flask, add 16.4 g of phosphorous acid, 2.30 g of p-toluenesulfonic acid, and 22.9 g of water. Start stirring and add 20.92 g of N-ethylglucamine dropwise. After the addition is complete, heat to 100 °C and add 16.23 g of formaldehyde dropwise. After the addition is complete, continue the reaction at 100 °C for 8 h. After cooling to room temperature, add liquid alkali to neutralize to pH 5.0 to obtain the organic phosphonate retarder HN-10.

[0061] Example 11

[0062] In a dry 250 mL three-necked flask, add 13.12 g of phosphorous acid, 2.04 g of p-toluenesulfonic acid, and 20.4 g of water. Start stirring and add 21.53 g of glucosamine hydrochloride dropwise. After the addition is complete, heat to 100 °C and add 16.23 g of formaldehyde dropwise. After the addition is complete, continue the reaction at 100 °C for 8 h. After cooling to room temperature, add liquid alkali to neutralize to pH 5.0 to obtain the organic phosphonate retarder HN-11.

[0063] Example 12

[0064] In a dry 250 mL three-necked flask, add 16.4 g of phosphorous acid, 2.59 g of phosphoric acid, and 25.7 g of water. Start stirring and add 27.73 g of glucosamine sulfate dropwise. After the addition is complete, heat to 100 °C and add 16.23 g of formaldehyde dropwise. After the addition is complete, continue the reaction at 100 °C for 9 h. After cooling to room temperature, add liquid alkali to neutralize to pH 5.0 to obtain the organic phosphonate retarder HN-12.

[0065] Comparative Example 1

[0066] Use the commercially available retarder sodium gluconate TNa as the comparative sample S-1.

[0067] Comparative Example 2

[0068] In a dry 250 mL three-necked flask, add 16.4 g of phosphorous acid, 2.77 g of sulfuric acid, and 16.5 g of water. Start stirring and add 5.91 g of n-propylamine dropwise. After the addition is complete, heat to 100 °C and add 16.23 g of formaldehyde dropwise. After the addition is complete, continue the reaction at 100 °C for 9 h. After cooling to room temperature, add liquid alkali to neutralize to pH 5.0 to obtain the organic phosphonate retarder S-2.

[0069] Comparative Example 3

[0070] In a dry 250 mL three-necked flask, add 16.4 g of phosphorous acid, 3.21 g of sulfuric acid, and 19.24 g of water. Start stirring, and add dropwise 6.01 g of ethylenediamine. After the addition is complete, heat to 110 °C and add dropwise 19.48 g of formaldehyde. After the addition is complete, continue the reaction at 110 °C for 7 h. After cooling to room temperature, add liquid alkali to neutralize to pH 5.0 to obtain the organic phosphonate retarder S-3.

[0071] Comparative Example 4

[0072] In a dry 250 mL three-necked flask, add 10.3 g of diethylenetriamine and 60 g of water. Start stirring, control the temperature at 120 °C, and then add dropwise a mixed solution containing 24.6 g of phosphorous acid, 29.2 g of formaldehyde, and 12.0 g of sulfuric acid. After the addition is complete, continue the reaction at 120 °C for 16 h. After cooling to room temperature, add liquid alkali to neutralize to pH 5.0 to obtain the retarder S-4.

[0073] Application Example

[0074] The retarders synthesized in the examples and comparative examples were compounded with the polycarboxylate superplasticizer PCE. The dosage of the polycarboxylate superplasticizer was 0.12%, and the dosage of the retarder was 0.015%. A cement dispersibility test was carried out. A paste experiment was carried out using Helin cement, and its initial fluidity and time-dependent loss were tested, and its setting time was also tested.

[0075] Table 1 Evaluation Table of Cement Paste Fluidity

[0076]

[0077] As can be seen from the table, the hydroxy-containing organic phosphonate retarder prepared in the present invention can improve the initial dispersion performance and slump retention performance of the polycarboxylate superplasticizer more than the comparative examples. And it has stronger retardation performance. The sample HN-12 has significantly stronger coagulation performance and slump retention performance than sodium gluconate with a low ratio of S-1 by introducing a phosphite group structure into the glucose structure. The possible reason is that the hydroxyl group and phosphonate group in the synthesized hydroxy-containing phosphonate retarder can synergistically inhibit cement hydration, resulting in stronger retardation performance and better slump retention performance.

[0078] The retarder and the polycarboxylate superplasticizer were compounded and then subjected to a mortar test. The dosage of the retarder was 0.02%, and the dosage of the superplasticizer was 0.18%. The results are shown in the following table:

[0079] Table 2 Evaluation of the Performance of the Superplasticizer Mortar

[0080]

[0081] From the results in Table 2, it can be seen that the synthesized hydroxy-containing organic phosphonate retarder has better performance in enhancing the dispersion and slump retention properties of polycarboxylate superplasticizer compared with the comparative sample. Compared with the comparative example S-3, the synthesized sample HN-1 has an additional hydroxyl group in its molecular structure besides the phosphite group. Due to this hydroxyl group structure, the HN-1 product shows more obvious improvement in fluidity and slump retention properties. The possible reason is that the synthesized hydroxy-containing organic phosphonate retarder has a stronger retardation effect. While delaying the hydration of cement, it promotes the improvement of the slump retention property of polycarboxylate superplasticizer.

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A preparation method of an organic phosphonate retarder, characterized in that, The specific steps are as follows: Add hydroxylamine monomer, water, phosphorous acid, and a catalyst into a dry reaction vessel. Dropwise add formaldehyde at a temperature of 100 - 130 °C for reaction. After reacting for 4 - 12 h, cool to room temperature, and add liquid alkali to neutralize to pH 5 to obtain the organic phosphonate retarder. The molar ratio of the active hydrogen in the amino group of the hydroxylamine monomer to phosphorous acid is 1:0.5 - 1, the molar ratio of phosphorous acid to formaldehyde is 1:1 - 1.2, the catalyst accounts for 3 - 10% of the total mass, and the mass of water accounts for 30 - 50% of the total mass. The hydroxylamine monomer is monoethanolamine, isopropanolamine, isobutanolamine, L-valinol, p-aminobenzyl alcohol, serinol, aminobutanetriol, 1,3-diamino-2-propanol, glucosamine, glucosamine methyl ester, glucosamine ethyl ester, glucosamine hydrochloride, or glucosamine sulfate.

2. The preparation method of an organic phosphonate retarder according to claim 1, characterized in that, The catalyst is concentrated sulfuric acid, phosphoric acid, or p-toluenesulfonic acid.

3. The preparation method of an organic phosphonate retarder according to claim 1, characterized in that, The liquid alkali is an aqueous sodium hydroxide solution with a mass fraction of 30%.

4. An organic phosphonate retarder prepared by the method according to any one of claims 1 - 3.

5. Application of an organic phosphonate retarder according to claim 4 as a retarder for cement-based materials.

6. The application according to claim 5, wherein The dosage of the organic phosphonate retarder is 0.1‰ - 0.5‰ of the mass of the gel material.

7. The application according to claim 6, wherein The gel material is cement and admixture.

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