Organic phosphonate retarder as well as preparation method and application thereof

Abstract

The invention discloses an organic phosphonate retarder as well as a preparation method and application thereof, and relates to the technical field of concrete admixtures. The preparation method specifically comprises the following steps: adding a hydroxylamine monomer, water, phosphorous acid and a catalyst into a reaction container, dropwise adding formaldehyde for reaction, cooling to room temperature after reaction, and adding caustic soda liquid for neutralization until the pH value is 5 to obtain the organic phosphonate retarder, the molar ratio of active hydrogen in amino groups in the hydroxylamine monomers to phosphorous acid is 1: (0.5-1), the molar ratio of phosphorous acid to formaldehyde is 1: (1-1.2), the mass of the catalyst accounts for 3-10% of the total mass, and the mass of water accounts for 30-50% of the total mass. The prepared organic phosphonate retarder has a phosphonic acid group and a hydroxyl group at the same time, calcium ions in a cement solution can be complexed at the same time to delay generation of hydration products, a solvation film can be formed on cement particles, hydration of cement is hindered, and the retarding effect is higher.

Description

Technical Field

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

[0002] As a new generation of high-performance water-reducing agent, polycarboxylic acid water-reducing agent is widely used in engineering construction due to its advantages of low dosage, high water-reducing rate, adjustable molecular structure, and green environmental protection, becoming the most important product in the field of concrete admixtures. However, when used in ordinary commercial concrete projects, polycarboxylic acid water-reducing agent also exposes some special problems of its own, such as adaptability to cement, sensitivity to aggregate mud content, and influence of external temperature changes. In actual engineering applications, it is often necessary to use it in combination with other types of admixtures. The use of retarder and high-performance water-reducing agent in combination can prolong the setting time of concrete and reduce slump loss. It is a reliable method to ensure the transportation, normal construction and quality of ready-mixed concrete.

[0003] Retarder mainly reduces the hydration rate and hydration heat of cement, thereby extending the setting time of concrete and maintaining the plasticity of fresh concrete for a long time. In summer concrete construction, due to the hot weather, rapid evaporation of water and rapid hydration of cement, concrete collapse is likely to occur. Adding an appropriate amount of retarder can improve the collapse resistance of concrete and improve the construction performance of concrete. Adding a retarder in large-volume concrete construction can delay the heat release of cement hydration, delay the appearance time of the hydration heat release peak, reduce temperature stress, and help improve the crack resistance of concrete. Commonly used concrete retarders can be divided into inorganic retarders and organic retarders according to their chemical composition. Commonly used inorganic retarders include phosphates, metaphosphates, borax, sodium fluorosilicate, etc. Organic retarders include hydroxycarboxylic acids, aminocarboxylic acids and their salts, polyols and their derivatives, sugars, etc.

[0004] The Chinese invention patent with the announcement number CN 116253832 B discloses a polymer for ultra-high temperature retarder, a preparation method and an ultra-high temperature retarder. The polymer structure has a high temperature resistant and strongly adsorbable cationic monomer, a polycarboxyl monomer and a high temperature resistant rigid monomer with a special configuration. As an ultra-high temperature retarder, the compound is applicable to a temperature range of 50 to 240°C or above. When the addition amount is 4.0% in the cementing cement slurry, the cement slurry thickening time can reach 546 min, and the thickening time has a good linear relationship with the temperature and the addition amount. However, it has the problem that the retarder dosage is too high and the retarding effect is limited.

[0005] The Chinese invention patent application with publication number CN 113999341 A discloses a composition for preparing a retarder and a retarder, which uses water, stabilizer, itaconic acid, acrylic acid, 2-acrylamide-2-methylpropanesulfonic acid, silane coupling agent, alkaline substance and initiator to prepare a retarder, which has good temperature resistance and can meet the requirements of 60-130°C; and the amount of the retarder has a good linear relationship, does not affect the strength of cement stone, and has good compatibility with other admixtures of oil well cement. However, it is a polymer material, the retarder group accounts for a small proportion, the retarding effect is poor, and the amount of the retarder added is high.

[0006] The Chinese invention patent with the announcement number CN 107188451 B discloses a long-acting retarder and a preparation method thereof, wherein a hydroxycarboxylic acid retarder and a polyol retarder are subjected to an esterification reaction to obtain a retarder, and the retarder of the obtained product will be released in the middle and late stages of the concrete solidification process, thereby obtaining a long-acting retarder. However, the retarding performance of this retarder is unstable, and in order to achieve the retarding effect, it is necessary to compound a phosphoric acid retarder for use.

[0007] The Chinese patent with the announcement number CN 111848978 B discloses a modified bagasse retarder and a preparation method thereof. The specific method is as follows: first pre-treat the bagasse with sulfite or chlorite to remove lignin and part of hemicellulose in the bagasse; then acid hydrolyze with a composite acid under catalytic conditions. The prepared retarder contains not only hydroxyl and carboxyl groups, but also functional groups such as phosphate groups. The retarding effect of the modified bagasse retarder is better than that of sodium gluconate at both room temperature (20°C) and high temperature (50°C), and has no effect on the later strength of concrete. However, the reaction process is relatively complicated, and the acid catalysis process contains water in the reaction system, the esterification efficiency is low, and the acid is difficult to graft onto the sucrose molecule. Summary of the invention

[0008] Technical problem to be solved: In view of the technical problems of low retarding efficiency and sensitive retarder dosage in the prior art, the present invention proposes an organic phosphonate retarder and its preparation method and application, which is obtained by reacting hydroxylamine monomers with phosphorous acid and formaldehyde in the presence of a catalyst. The prepared organic phosphonate retarder has both phosphonic acid groups and hydroxyl groups, can complex calcium ions in cement solution at the same time to delay the formation of hydration products, and can form a solvation film on cement particles to hinder cement hydration, and has a stronger retarding effect.

[0009] Technical solution: The first object of the present invention is to provide a method for preparing an organic phosphonate retarder, which is as follows: adding hydroxylamine monomer, water, phosphorous acid and a catalyst into a dry reaction container, adding formaldehyde dropwise for reaction at a temperature of 100-130°C, cooling to room temperature after the reaction for 4-12 hours, adding liquid alkali to neutralize to a pH of 5 to obtain an organic phosphonate retarder, wherein the hydroxylamine monomer is an organic substance containing both amino and hydroxyl groups in its molecular structure, the molar ratio of 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, serine, aminobutanetriol, 1,3-diamino-2-propanol, glucosamine, meglumine, ethylglucosamine, 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 a sodium hydroxide aqueous 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 cement-based material retarder.

[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 mineral powder may also be mixed.

[0017] The retarding mechanism of phosphates is that phosphates are adsorbed and complexed with calcium ions in cement slurry to hinder the formation of hydration products; while polyol and sugar retarders mainly produce a thin film by adsorption on the surface of cement particles, which is coated on the surface of cement particles to hinder the hydration of cement slurry. The present invention introduces phosphonic acid groups into polyhydroxy compounds to synthesize a retarder containing both hydroxyl and phosphonic acid groups, which can not only complex calcium ions in cement slurry through phosphonic acid groups to inhibit the formation of hydration products, but also adsorb on the surface of cement particles to form a thin film to hinder the hydration of cement particles. With the synergy of the retarding mechanisms of the two, the retarder obtained has a stronger retarding effect. Prepare a retarder with ultra-long retarding time and controllable time (high retarder dosage, long retarding time, low dosage, short retarding time).

[0018] Beneficial effects: The present invention grafts phosphorous acid onto a polyhydroxy compound through the Mannich reaction between the amino group in the hydroxylamine monomer and phosphorous acid, thereby generating an organic phosphonate retarder containing both a hydroxyl group and a phosphonic acid group. The reaction conditions are simple and easy to operate, and the obtained retarder has stable structure and performance. Due to the strong complexing and adsorption capacity of the phosphonic acid group, it can complex the calcium ions in the cement pore solution and inhibit the formation of hydration products. At the same time, it can also be adsorbed on cement particles to form a solvated film to hinder cement hydration. The organic phosphonate retarder of the present invention has a stronger retarding performance than other retarders. At a dosage of 0.015%, the retarder can extend the initial setting time of cement paste by more than 2.5 hours compared with sodium gluconate. DETAILED DESCRIPTION

[0019] In order to better understand the present invention, the content of the present invention is further explained below in conjunction with the examples, but the content of the present invention is not limited to the following examples. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

[0020] The cement used is Helin 42.5RPO. The sand is standard sand. The cement paste and mortar fluidity tests are carried out in accordance with GB / T8077-2000, and the cement paste setting time is tested in accordance with GB / T 1346-2011.

[0021] The raw materials used in the examples of this specification come from the following sources:

[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] seratinol, AR, 98%;

[0031] aminomethamine, AR, 99%;

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

[0033] glucosamine, AR, 98%;

[0034] meglumine, AR, 98%;

[0035] glucamine, AR, 98%;

[0036] Glucosamine hydrochloride, AR, 97%;

[0037] glucosamine sulfate, AR, 98%;

[0038] In the comparative example, sodium gluconate TNa, AR, 99%;

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

[0040] Ethylenediamine, AR, 98%, all purchased from Sinopharm Chemical Reagent Co., Ltd.

[0041] Example 1

[0042] In a dry 250mL three-necked flask, add 16.4g of phosphorous acid, 2.77g of sulfuric acid and 16.6g of water, start stirring, add 6.11g of monoethanolamine dropwise, heat to 120℃, add 16.23g of formaldehyde dropwise, continue to react at 120℃ for 6h, cool to room temperature, add liquid alkali to neutralize to pH 5.0, and obtain organic phosphonate retarder HN-1.

[0043] Example 2

[0044] In a dry 250mL three-necked flask, add 16.4g of phosphorous acid, 4.94g of sulfuric acid and 18.5g of water, start stirring, add 8.91g of isobutanolamine dropwise, heat to 110°C, add 17.86g of formaldehyde dropwise, continue to react at 110°C for 8h, cool to room temperature, add liquid alkali to neutralize to pH 5.0, and obtain organic phosphonate retarder HN-2.

[0045] Example 3

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

[0047] Example 4

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

[0049] Example 5

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

[0051] Example 6

[0052] In a dry 250mL three-necked flask, add 16.4g of phosphorous acid, 6.39g of sulfuric acid and 19.18g of water, start stirring, add 12.11g of aminobutanetriol dropwise, heat to 120°C, add 16.23g of formaldehyde dropwise, continue to react at 120°C for 6h, cool to room temperature, add liquid alkali to neutralize to pH 5.0, and obtain organic phosphonate retarder HN-6.

[0053] Example 7

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

[0055] Example 8

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

[0057] Example 9

[0058] In a dry 250mL three-necked flask, add 16.4g of phosphorous acid, 2.23g of phosphoric acid and 22.4g of water, start stirring, add 19.52g of meglumine dropwise, heat to 100℃, add 16.23g of formaldehyde dropwise, continue to react at 100℃ for 10h, cool to room temperature, add liquid alkali to neutralize to pH 5.0, and obtain organic phosphonate retarder HN-9.

[0059] Example 10

[0060] In a dry 250mL three-necked flask, add 16.4g of phosphorous acid, 2.30g of p-toluenesulfonic acid and 22.9g of water, start stirring, add 20.92g of ethylglucamine dropwise, heat to 100℃, add 16.23g of formaldehyde dropwise, continue to react at 100℃ for 8h, cool to room temperature, add liquid alkali to neutralize to pH 5.0, and obtain organic phosphonate retarder HN-10.

[0061] Embodiment 11

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

[0063] Example 12

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

[0065] Comparative Example 1

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

[0067] Comparative Example 2

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

[0069] Comparative Example 3

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

[0071] Comparative Example 4

[0072] Add 10.3 g of diethylenetriamine and 60 g of water into a dry 250 mL three-necked flask, start stirring, control the temperature at 120°C, and then drop 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 hours. After cooling to room temperature, add liquid alkali to neutralize to pH 5.0 to obtain retarder S-4.

[0073] Application Examples

[0074] The retarder synthesized in the embodiment and the comparative example was compounded with the polycarboxylate water-reducing agent PCE, with the polycarboxylate water-reducing agent dosage of 0.12% and the retarder dosage of 0.015%. A cement dispersibility test was carried out, and a slurry experiment was carried out using Helin cement to test its initial fluidity and time loss, and its setting time was tested.

[0075] Table 1 Evaluation table of cement paste fluidity

[0076]

[0077] It can be seen from the table that the hydroxyl-containing organic phosphonate retarder prepared by the present invention can improve the initial dispersibility and slump retention performance of the polycarboxylate water-reducing agent more than the comparative example. And it has stronger retarding performance. Sample HN-12 introduces the phosphite structure into the glucose structure, and its coagulation performance and slump retention performance are obviously stronger than the sodium gluconate with a low proportion of S-1. The possible reason is that the hydroxyl group and the phosphonic acid group in the synthesized hydroxyl-containing phosphonate retarder can synergistically inhibit cement hydration, so that the retarding performance is stronger and the slump retention performance is better.

[0078] The mortar test was carried out after the retarder and polycarboxylate water reducer were compounded. The retarder dosage was 0.02% and the water reducer dosage was 0.18%. The results are shown in the following table:

[0079] Table 2 Performance evaluation of water reducing agent mortar

[0080]

[0081] From the results in Table 2, it can be seen that the synthesized hydroxyl-containing organic phosphonate retarder has better dispersion and slump retention performance of the polycarboxylate water-reducing agent than the control sample. Compared with the comparative example S-3, the synthetic sample HN-1 has an additional hydroxyl group in addition to the phosphite group in the molecular structure. Because of this hydroxyl structure, the HN-1 product has more obvious improvements in fluidity and slump retention performance. The possible reason is that the synthesized hydroxyl-containing organic phosphonate retarder has a stronger retarding effect, which delays cement hydration while promoting the improvement of the slump retention performance of the polycarboxylate water-reducing agent.

[0082] Finally, it should be noted that the above implementation modes are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned implementation modes, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned implementation modes can still be modified, or some or all of the technical features therein can be replaced by equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the implementation modes of the present invention.

Claims

1. A method for preparing an organic phosphonate retarder, characterized in that: Specifically, hydroxylamine monomer, water, phosphorous acid and a catalyst are added into a dry reaction container, formaldehyde is added dropwise for reaction at a temperature of 100-130°C, the reaction is continued for 4-12 hours, the reaction is cooled to room temperature, and liquid alkali is added to neutralize the reaction until the pH value reaches 5, thereby obtaining an organic phosphonate retarder, wherein the hydroxylamine monomer is an organic substance containing both amino group and hydroxyl group in its molecular structure, the molar ratio of 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.

2. The method for preparing an organic phosphonate retarder according to claim 1, characterized in that: The hydroxylamine monomer is monoethanolamine, isopropanolamine, isobutanolamine, L-valinol, p-aminobenzyl alcohol, serine, aminobutanetriol, 1,3-diamino-2-propanol, glucosamine, meglumine, ethylglucosamine, glucosamine hydrochloride or glucosamine sulfate.

3. The method for preparing an organic phosphonate retarder according to claim 1, characterized in that: The catalyst is concentrated sulfuric acid, phosphoric acid or p-toluenesulfonic acid.

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

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

6. Use of an organic phosphonate retarder according to claim 5 as a cement-based material retarder.

7. The use according to claim 6, characterized in that: The dosage of the organic phosphonate retarder is 0.1‰-0.5‰ of the mass of the gel material.

8. The use according to claim 7, characterized in that: The gel material is cement and admixture.

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