Concrete foaming agent as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of building materials, and particularly relates to a concrete foaming agent and a preparation method and application thereof. The concrete foaming agent comprises the following raw materials: a composite foaming component, hyperbranched modified alkylolamide, a polycarboxylic acid water reducing agent and water, the composite foaming component comprises a surfactant and modified vegetable protein; the modified vegetable protein is obtained by carrying out a modification reaction on vegetable protein and an alkaline substance in the presence of a solvent; the hyperbranched modified alkylolamide is obtained by carrying out melt polymerization reaction on cyclic fatty acid, alkylol amine and a branched monomer; the degree of functionality of the branched monomer is 2 or more. The concrete foaming agent is characterized in that the surfactant and the modified vegetable protein are adopted as composite foaming components, the composite foaming components are compounded with the hyperbranched modified alkylolamide and the polycarboxylic acid water reducing agent to play a mutual matching role, and therefore the concrete foaming agent which is good in foaming effect and high in foam stability is obtained, and the applicable range is wider.

Description

Technical Field

[0001] The invention belongs to the technical field of building materials, and particularly relates to a concrete foaming agent and a preparation method and application thereof. Background Art

[0002] Foamed concrete is a lightweight porous concrete with a closed-cell structure that uses cement as the main cementitious material, introduces bubbles into the slurry made of cement, aggregates, admixtures and water, and is mixed, cast and cured. Compared with ordinary concrete, foamed concrete has many advantages such as simple production process, thermal insulation, fire resistance and earthquake resistance. Foaming agent is one of the important raw materials for the production of foamed concrete, and is the main condition and material basis for the formation of foamed concrete. It can reduce the surface tension of liquid, generate a large number of bubbles and maintain high stability in the concrete slurry. It is often used as a concrete admixture for the production of lightweight porous materials.

[0003] Concrete foaming agents include physical foaming agents and chemical foaming agents. Among them, physical foaming agents form foams by introducing a large amount of air into the foaming agent through mechanical force, and can be divided into rosin foaming agents, surfactant foaming agents, protein foaming agents and composite foaming agents. Rosin foaming agents have a low bubble volume and poor stability of the foam formed. Surfactant foaming agents have the disadvantages of thin bubble walls, poor stability and a large impact on cement strength, which limits their application. Composite foaming agents are composed of a variety of functional components, combining the advantages of a variety of foaming agents, but the composition is complex, the production process requirements are high, it is not conducive to promotion and application, and it may also contain harmful components that will affect the environment, and the effect of improving the foaming effect and stability is also limited. Therefore, it is urgent to prepare an environmentally friendly concrete foaming agent with good foaming effect. Summary of the invention

[0004] The purpose of the present invention is to provide a concrete foaming agent and a preparation method and application thereof in view of the shortcomings of existing composite foaming agents, such as complex components and unstable foaming effect. The concrete foaming agent has simple components, low production process requirements and good foaming effect.

[0005] In a first aspect, the present invention provides a concrete foaming agent, wherein the raw materials of the concrete foaming agent include a composite foaming component, a hyperbranched modified alkyl alcohol amide, a polycarboxylic acid water reducer and water; the composite foaming component includes a surfactant and a modified plant protein; the modified plant protein is obtained by a modification reaction of plant protein and an alkaline substance in the presence of a solvent; the hyperbranched modified alkyl alcohol amide is obtained by a melt polymerization reaction of a cyclic fatty acid, an alkyl alcohol amine and a branching monomer; and the functionality of the branching monomer is greater than 2.

[0006] In a preferred embodiment, the content of the composite foaming component is 20 to 40 parts by weight, the hyperbranched modified alkyl alcohol amide is 3 to 7 parts by weight, the content of the polycarboxylic acid water reducer is 10 to 15 parts by weight, and the content of water is 40 to 70 parts by weight.

[0007] In a preferred embodiment, the mass ratio of the surfactant to the modified plant protein is (1-1.5):1.

[0008] In a preferred embodiment, during the preparation of the modified plant protein, the alkaline substance exists in the form of an alkaline solution.

[0009] In a preferred embodiment, the concentration of the alkaline substance in the alkaline solution is 0.05-0.1 mol / L.

[0010] In a preferred embodiment, the mass ratio of the plant protein to the alkaline solution is 1:(10-50).

[0011] In a preferred embodiment, the plant protein is selected from at least one of tea cake protein, soy protein, pea protein and brown rice protein.

[0012] In a preferred embodiment, the alkaline substance is selected from at least one of sodium hydroxide, potassium hydroxide and ammonium hydroxide.

[0013] In a preferred embodiment, the modification reaction is carried out at a temperature of 30 to 50° C. and for a time of 8 to 10 hours.

[0014] In a preferred embodiment, the melt polymerization reaction is carried out in the presence of a catalyst.

[0015] In a preferred embodiment, the mass ratio of the cyclic fatty acid, alcohol amide, branched monomer and catalyst is 1:(1-3):(0.8-1.0):(0.5-0.8).

[0016] In a preferred embodiment, the cyclic fatty acid is selected from at least one of cyclohexanecarboxylic acid, cyclopentanecarboxylic acid, cycloheptanecarboxylic acid, cyclobutanecarboxylic acid and cyclooctanecarboxylic acid.

[0017] In a preferred embodiment, the alkanolamine is at least one selected from triethanolamine, diethanolamine, triisopropanolamine and diisopropanolamine.

[0018] In a preferred embodiment, the branching monomer is selected from at least one of chitosan, pentaerythritol and sorbitol.

[0019] In a preferred embodiment, the catalyst is selected from at least one of dipotassium hydrogen phosphate, trifluoromethanesulfonic acid, p-toluenesulfonic acid, and dibutyltin dilaurate.

[0020] In a preferred embodiment, the melt polymerization reaction is carried out at a temperature of 160 to 180° C. and for a time of 6 to 8 hours.

[0021] In a preferred embodiment, the surfactant is selected from at least one of potassium cocoate soap, sodium dodecylbenzenesulfonate, laurylamidopropyl dimethyl tertiary amine, erucic acid amidopropyl dimethyl tertiary amine, oleic acid amidopropyl hydroxysulfobetaine, sodium lauryl sulfate, sodium fatty acid methyl ester sulfonate, and sodium α-olefin sulfonate.

[0022] In a preferred embodiment, the number average molecular weight of the polycarboxylate water-reducing agent is 30,000 to 50,000 mol / L.

[0023] In a second aspect, the present invention also provides a method for preparing the above concrete foaming agent, which comprises the following steps: uniformly mixing the composite foaming component, hyperbranched modified alkyl alcohol amide, polycarboxylic acid water reducer and water under heating conditions to obtain the concrete foaming agent.

[0024] In a preferred embodiment, the heating temperature is 60-90° C. and the heating time is 4-20 min.

[0025] In a third aspect, the present invention also provides the use of the above concrete foaming agent in building materials.

[0026] The key of the present invention is to use surfactant and modified plant protein as composite foaming components, and then compound them with hyperbranched modified alkyl alcohol amide and polycarboxylic acid water reducer to play a mutual coordination effect, thereby obtaining a concrete foaming agent with good foaming effect and strong foam stability, which can be applied more widely. It is speculated that the reason may be due to: using surfactant and modified plant protein compound as foaming components, the foaming multiple is high, and rich foam can be produced, and hyperbranched modified alkyl alcohol amide has rich functional groups such as hydroxyl and carboxyl, which is conducive to improving the stability of foam, and polycarboxylic acid water reducer can make the concrete foaming agent add to concrete for foaming, and can form dense adsorption layer and network structure in concrete, thereby effectively improving the stability of the foam produced. It can be seen that the concrete foaming agent provided by the present invention has simple components, does not contain harmful components that affect the environment, is green and environmentally friendly, has good foaming effect, high foam stability, and is highly applicable. DETAILED DESCRIPTION

[0027] The raw materials of the concrete foaming agent provided by the present invention include composite foaming components, hyperbranched modified alkyl alcohol amide, polycarboxylic acid water reducer and water; the composite foaming components include surfactants and modified plant proteins; the modified plant proteins are obtained by modifying plant proteins with alkaline substances in the presence of solvents; the hyperbranched modified alkyl alcohol amide is obtained by melt polymerization of cyclic fatty acids, alkyl alcohol amines and branching monomers. The branching monomer is a type of multifunctional compound containing at least one of hydroxyl, carboxyl and amino groups, and its functionality is 2 or more, preferably 2 to 10, such as 2, 3, 4, 5, 6, 8, 10 or any value therebetween. The functionality of the branching monomer refers to the number of hydroxyl, carboxyl and amino groups contained in the molecular structure of a branching monomer.

[0028] In the present invention, by weight, the content of the composite foaming component is preferably 20 to 40 parts by weight, such as 20, 25, 30, 35, 40 parts by weight or any value therebetween; the hyperbranched modified alkyl alcohol amide is preferably 3 to 7 parts by weight, such as 3, 4, 5, 6, 7 parts by weight or any value therebetween; the content of the polycarboxylic acid water reducer is preferably 10 to 15 parts by weight, such as 10, 11, 12, 13, 14, 15 parts by weight or any value therebetween; the content of the water is preferably 40 to 70 parts by weight, such as 40, 45, 50, 55, 60, 65, 70 parts by weight or any value therebetween. The content of each component in the concrete foaming agent is controlled within the above preferred range, which is more conducive to the mutual coordination between the composite foaming component, the hyperbranched modified alkyl alcohol amide and the polycarboxylic acid water reducer, and can further improve the foaming performance and foam stabilization performance of concrete foaming.

[0029] In the present invention, the mass ratio of the surfactant to the modified vegetable protein is preferably (1-1.5):1, such as 1:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1 or any value therebetween. Controlling the mass ratio of the surfactant to the modified vegetable protein within the above preferred range is more conducive to cooperating with each other to effectively reduce the surface tension of the liquid, thereby improving the foaming performance of the concrete foaming agent and generating rich foam.

[0030] In the present invention, the preparation method of the modified plant protein preferably comprises: performing a modification reaction on the plant protein and the alkaline substance in the presence of a solvent, and the obtained reaction solution is concentrated to obtain the modified plant protein. In the preparation process of the modified plant protein, the plant protein or the alkaline substance may be mixed with the solvent first and then the remaining another substance is added to mix and the modification reaction may be carried out, or the plant protein and the alkaline substance may be added to the solvent at the same time and then mixed and then the modification reaction is carried out. Preferably, the alkaline substance is first mixed with the solvent to form an alkaline solution, and then the plant protein is added to the alkaline solution for the modification reaction. The solvent may be a conventional choice in the art, preferably water.

[0031] In the present invention, the alkaline substance is preferably present in the form of an alkaline solution, that is, the alkaline solution is obtained by mixing the alkaline substance with a solvent, and the solvent is preferably water. The concentration of the alkaline substance in the alkaline solution is preferably 0.05-0.1 mol / L, such as 0.05 mol / L, 0.06 mol / L, 0.07 mol / L, 0.08 mol / L, 0.09 mol / L, 0.1 mol / L or any value therebetween. The mass ratio of the plant protein to the alkaline solution is preferably 1:(10-50), such as 1:10, 1:15, 1:20, 1:25, 1:30, 1:35, 1:40, 1:45, 1:50 or any value therebetween. The concentration of the alkaline substance and / or the mass ratio of the plant protein to the alkaline solution are controlled within the above-mentioned preferred range. The modified plant protein obtained under this condition is more conducive to the interaction with the surfactant, thereby further improving the foaming effect of the concrete foaming agent.

[0032] The present invention does not specifically limit the type of the plant protein, which can be a conventional choice in the art, and specific examples thereof include but are not limited to: at least one of tea cake protein, soy protein, pea protein, and brown rice protein. The present invention does not specifically limit the type of the alkaline substance, which can be a conventional choice in the art, and specific examples thereof include but are not limited to: at least one of sodium hydroxide, potassium hydroxide, and ammonium hydroxide.

[0033] In the present invention, the temperature of the modification reaction is preferably 30-50°C, such as 30°C, 35°C, 40°C, 45°C, 50°C or any value therebetween; the time is preferably 8-10h, such as 8h, 8.5h, 9h, 9.5h, 10h or any value therebetween. Controlling the temperature and time of the modification reaction within the above preferred range is more conducive to the modification of the plant protein by the alkaline substance, thereby being more conducive to improving the foaming performance of the modified plant protein. The temperature of the concentration treatment is preferably 40-60°C, such as 40°C, 45°C, 50°C, 55°C, 60°C or any value therebetween; the time is preferably 3-5h, such as 3h, 3.5h, 4h, 4.5h, 5h or any value therebetween.

[0034] In a specific embodiment, the preparation method of the modified plant protein includes: mixing the plant protein with an alkaline solution and performing a modification reaction at 30-50°C for 8-10 hours, filtering after the reaction is completed, and concentrating the obtained filtrate at 40-60°C for 3-5 hours to obtain the modified plant protein.

[0035] In the present invention, the melt polymerization is preferably carried out in the presence of a catalyst. The mass ratio of the cyclic fatty acid to the alcohol amide is preferably 1: (1-3), such as 1: 1, 1: 1.2, 1: 1.5, 1: 1.8, 1: 2, 1: 2.2, 1: 2.5, 1: 2.8, 1: 3 or any value therebetween. The mass ratio of the cyclic fatty acid to the branched monomer is preferably 1: (0.8-1.0), such as 1: 0.8, 1: 0.85, 1: 0.9, 1: 0.95, 1: 1.0 or any value therebetween, which is more conducive to obtaining a polymer with a certain degree of branching and improving the stability of the foam. The mass ratio of the cyclic fatty acid to the catalyst is preferably 1: (0.5-0.8), such as 1: 0.5, 1: 0.6, 1: 0.7, 1: 0.8 or any value therebetween.

[0036] In the present invention, the temperature of the melt polymerization reaction is preferably 160-180°C, such as 160°C, 165°C, 170°C, 175°C, 180°C or any value therebetween; the time is preferably 6-8h, such as 6h, 6.5h, 7h, 7.5h, 8h or any value therebetween.

[0037] In the present invention, the cyclic fatty acid is preferably a compound having an R-COOH structure, wherein R is C4 to C 12 The cycloalkyl group includes, but is not limited to, at least one of cyclobutane, cyclopentane, cyclohexane, cycloheptane, and cyclooctane. The cyclic fatty acid includes, but is not limited to, at least one of cyclohexanecarboxylic acid, cyclopentanecarboxylic acid, cycloheptanecarboxylic acid, cyclobutanecarboxylic acid, and cyclooctanecarboxylic acid.

[0038] In the present invention, the alkanolamine preferably has (R1) n -N-(R2-OH) m A class of compounds of the structure, wherein n can be 0 or 1, m can be 2 or 3, n+m=3, R1 is a hydrogen atom or a methyl group, and R2 is a C1-C5 alkylene group, and its specific implementation includes but is not limited to: at least one of methylene, ethylene, n-propylene, isopropylene, n-butylene, isobutylene, n-pentylene, and neopentylene. Specific examples of the alkanolamine include but are not limited to: at least one of triethanolamine, diethanolamine, triisopropanolamine, and diisopropanolamine.

[0039] In the present invention, specific examples of the branching monomer include, but are not limited to, at least one of chitosan, pentaerythritol, and sorbitol.

[0040] In the present invention, specific examples of the catalyst include, but are not limited to: at least one of dipotassium hydrogen phosphate, trifluoromethanesulfonic acid, p-toluenesulfonic acid, and dibutyltin dilaurate.

[0041] In the present invention, the surfactant can be a conventional choice in the art, such as at least one of anionic surfactants, cationic surfactants, and amphoteric surfactants, and specific examples thereof include but are not limited to: potassium cocoate soap, lauryl amide propyl dimethyl tertiary amine, erucic acid amide propyl dimethyl tertiary amine, oleic acid amide propyl hydroxysulfobetaine, sodium dodecylbenzene sulfonate, sodium dodecyl sulfate, sodium fatty acid methyl ester sulfonate, and at least one of sodium α-olefin sulfonate.

[0042] In the present invention, the number average molecular weight Mn of the polycarboxylate water reducer is preferably 30000-50000 mol / L, such as 30000 mol / L, 35000 mol / L, 40000 mol / L, 45000 mol / L, 50000 mol / L or any value therebetween. The polycarboxylate water reducer is preferably a TPEG-MA foam-stabilizing polycarboxylate water reducer and / or an EPEG-MAA-foam-stabilizing polycarboxylate water reducer. The ratio of methallyl polyoxyethylene ether to methacrylamide blocks in the TPEG-MA foam-stabilizing polycarboxylate water reducer is preferably (4-5):1, such as 4:1, 4.2:1, 4.5:1, 4.8:1, 5:1 or any value therebetween. The ratio of allyl polyoxyethylene ether to methacrylic acid block in the EPEG-MAA foam-stabilizing polycarboxylate water-reducing agent is preferably (4-6):1, such as 4:1, 4.5:1, 5:1, 5.5:1, 6:1 or any value therebetween.

[0043] In the present invention, the preparation method of the concrete foaming agent comprises the following steps: uniformly mixing the composite foaming component, hyperbranched modified alkyl alcohol amide, polycarboxylic acid water reducer and water to obtain the concrete foaming agent. The preparation process of the above concrete foaming agent does not specifically limit the order of mixing. The composite foaming component, hyperbranched modified alkyl alcohol amide, and at least one of the polycarboxylic acid water reducer can be first mixed with water under heating conditions, and then the remaining raw materials are added to continue mixing under heating conditions. In a preferred embodiment, the mixing method includes first mixing the composite foaming component, the polycarboxylic acid water reducer and water at 60-90°C and 50-180r / min, stirring and mixing for 2-10min, then adding the hyperbranched modified alkyl alcohol amide and continuing to stir and mix for 2-10min, and then cooling to room temperature to obtain the concrete foaming agent.

[0044] The present invention will be described in detail below through specific embodiments.

[0045] Example 1

[0046] 1.1 Preparation of modified vegetable protein: Take 1g of vegetable protein (soy protein) and place it in a 500mL beaker, add 20g of sodium hydroxide solution (concentration of 0.05mol / L) and mix, react at 30℃ for 10h and then filter, and concentrate the filtrate in a 40℃ oven for 5h to obtain modified vegetable protein A1.

[0047] 1.2 Preparation of hyperbranched modified alkyl alcohol amide: In a four-necked flask equipped with a stirrer, cyclohexanecarboxylic acid, triethanolamine, chitosan and dipotassium hydrogen phosphate were added in a mass ratio of 1:1:0.8:0.5, and melt polymerization was carried out at 160°C for 8 hours. After the reaction, the product was washed, filtered and vacuum dried to obtain hyperbranched modified alkyl alcohol amide B1.

[0048] 1.3 Preparation of concrete foaming agent: Weigh 10 parts by weight of potassium cocoate soap, 10 parts by weight of modified vegetable protein A1, 10 parts by weight of TPEG-MA foam-stabilizing polycarboxylic acid water reducer (Mn=30000 mol / L, the ratio of methyl allyl polyoxyethylene ether to methyl acrylamide block is 4:1) and 20 parts by weight of water, heat in a 60°C water bath, stir slowly at 50 r / min for 10 min, then add 3 parts by weight of hyperbranched modified alkyl alcohol amide B1, continue stirring for 10 min after adding, then let stand and cool to room temperature to obtain a concrete foaming agent.

[0049] Example 2

[0050] 2.1 Preparation of modified plant protein: Take 3g of plant protein (tea cake protein) and place it in a 500mL beaker, add 60g of potassium hydroxide alkali solution (concentration of 0.07mol / L) and mix, react at 40℃ for 9h and then filter, and concentrate the filtrate in a 50℃ oven for 4h to obtain modified plant protein A2.

[0051] 2.2 Preparation of hyperbranched modified alkyl alcohol amide: In a four-necked flask equipped with a stirrer, cyclopentanecarboxylic acid, diethanolamine, pentaerythritol and trifluoromethanesulfonic acid were added in a mass ratio of 1:1.5:0.9:0.7, and melt polymerization was carried out at 170°C for 7 hours. After the reaction, the product was washed, filtered and vacuum dried to obtain hyperbranched modified alkyl alcohol amide B2.

[0052] 2.3 Preparation of concrete foaming agent: Weigh 15 parts by weight of lauryl amide propyl dimethyl tertiary amine, 10 parts by weight of modified plant protein A2, 12 parts by weight of TPEG-MA foam-stabilizing polycarboxylic acid water-reducing agent (Mn=50000 mol / L, the ratio of methyl allyl polyoxyethylene ether to methyl acrylamide block is 5:1) and 60 parts by weight of water, heat in a water bath at 80°C, stir slowly at 150r / min for 4 minutes, then add 5 parts by weight of hyperbranched modified alkyl alcohol amide B2, continue stirring for 4 minutes after addition, then let stand and cool to room temperature to obtain the concrete foaming agent.

[0053] Example 3

[0054] 3.1 Preparation of modified plant protein: Take 2g of plant protein (pea protein) and place it in a 500mL beaker, add 100g of sodium hydroxide solution (concentration of 0.1mol / L) and mix, react at 50℃ for 8h and then filter, and concentrate the filtrate in a 60℃ oven for 3h to obtain modified plant protein A3.

[0055] 3.2 Preparation of hyperbranched modified alkyl alcohol amide: In a four-necked flask equipped with a stirrer, cycloheptanecarboxylic acid, triethanolamine, sorbitol and dipotassium hydrogen phosphate were added in a mass ratio of 1:2:1.0:0.8, and melt polymerization was carried out at 180°C for 6 hours. After the reaction, the product was washed, filtered and vacuum dried to obtain hyperbranched modified alkyl alcohol amide B3.

[0056] 3.3 Preparation of concrete foaming agent: Weigh 20 parts by weight of erucic acid amide propyl dimethyl tertiary amine, 15 parts by weight of modified plant protein A3, 15 parts by weight of EPEG-MAA foam-stabilizing polycarboxylic acid water reducer (Mn=50000 mol / L, the ratio of allyl polyoxyethylene ether to methacrylic acid block is 5.5:1) and 70 parts by weight of water, heat in a 60°C water bath, slowly stir at 180 r / min for 2 minutes, then add 7 parts by weight of hyperbranched modified alkyl alcohol amide B3, continue stirring for 2 minutes after addition, let stand and cool to room temperature, and then the concrete foaming agent can be obtained.

[0057] Comparative Example 1

[0058] The commercially available concrete foaming agent is purchased from Sasol and its brand is MARLINAT 6104.

[0059] Comparative Example 2

[0060] Preparation of reference concrete foaming agent: Weigh 10 parts by weight of potassium cocoate soap, 10 parts by weight of soy protein, 10 parts by weight of TPEG-MA foam-stabilizing polycarboxylic acid water reducer (Mn=30000 mol / L, methyl allyl polyoxyethylene ether and methyl acrylamide block ratio of 4:1) and 20 parts by weight of water, heat in a 60°C water bath, slowly stir at 50 r / min for 10 min, then add 3 parts by weight of hyperbranched modified alkyl alcohol amide B1, continue stirring for 10 min after adding, then let stand and cool to room temperature to obtain a reference concrete foaming agent.

[0061] Comparative Example 3

[0062] Weigh 20 parts by weight of modified plant protein A1, 10 parts by weight of TPEG-MA foam-stabilizing polycarboxylic acid water-reducing agent (Mn=30000 mol / L, the ratio of methyl allyl polyoxyethylene ether to methyl acrylamide block is 4:1) and 20 parts by weight of water, heat in a 60°C water bath, slowly stir at 50 r / min for 10 min, then add 3 parts by weight of hyperbranched modified alkyl alcohol amide B1, continue stirring for 10 min after adding, then let stand and cool to room temperature to obtain a reference concrete foaming agent.

[0063] Comparative Example 4

[0064] Weigh 10 parts by weight of potassium cocoate soap, 10 parts by weight of modified vegetable protein A1 and 20 parts by weight of water, heat them in a 60° C. water bath, slowly stir them at 50 r / min for 10 min, then add 13 parts by weight of hyperbranched modified alkyl alcohol amide B1, continue stirring for 10 min after adding, then let it stand and cool to room temperature to obtain a concrete foaming agent.

[0065] Comparative Example 5

[0066] 5.1 Preparation of alkyl alcohol amide: In a four-necked flask equipped with a stirrer, cyclohexanecarboxylic acid, triethanolamine and dipotassium hydrogen phosphate were added in a mass ratio of 1:1:0.8, and melt polymerization was carried out at 160°C for 8 hours. After the reaction, the product was washed, filtered and vacuum dried to obtain alkyl alcohol amide DB1.

[0067] 5.2 Preparation of concrete foaming agent: Weigh 10 parts by weight of potassium cocoate soap, 10 parts by weight of modified vegetable protein A1, 10 parts by weight of foam-stabilizing polycarboxylic acid water-reducing agent TPEG-MA (Mn=30000 mol / L, the ratio of methyl allyl polyoxyethylene ether to methyl acrylamide block is 4:1) and 20 parts by weight of water, heat in a 60°C water bath, stir slowly at 50 r / min for 10 min, add 3 parts by weight of alkyl alcohol amide DB1, continue stirring for 10 min after adding, then let stand and cool to room temperature to obtain a reference concrete foaming agent.

[0068] Test Case

[0069] The performance of the concrete foaming agents in the above examples and comparative examples were tested according to the method in JCT 2199-2013 "Foaming Agents for Foamed Concrete", and the results are shown in Table 1.

[0070] Table 1

[0071]

[0072] From the results in Table 1, it can be seen that compared with the commercially available concrete foaming agent (Comparative Example 1), the concrete foaming agent provided by Examples 1 to 3 of the present invention has significantly improved foaming multiples, lower 1h settlement distance and lower 1h water bleeding rate, and excellent foaming performance. From the comparison results of Example 1 and Comparative Examples 2 to 4, it can be seen that when unmodified plant protein or unbranched modified alkyl alcohol amide is used, or any one of the surfactant and polycarboxylic acid water reducer is lacking, the foaming multiple of the concrete foaming agent decreases, the 1h settlement distance and 1h water bleeding rate increase, and the foaming effect becomes worse.

[0073] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and intent of the present invention.

Claims

1. A concrete foaming agent, characterized in that: The raw materials of the concrete foaming agent include composite foaming components, hyperbranched modified alkyl alcohol amide, polycarboxylic acid water reducer and water; the composite foaming components include surfactant and modified plant protein; The modified plant protein is obtained by carrying out a modification reaction between plant protein and an alkaline substance in the presence of a solvent; the hyperbranched modified alkyl alcohol amide is obtained by carrying out a melt polymerization reaction between cyclic fatty acids, alkyl alcohol amines and branching monomers; and the functionality of the branching monomer is greater than 2.

2. The concrete foaming agent according to claim 1, characterized in that In parts by weight, the content of the composite foaming component is 20 to 40 parts by weight, the content of the hyperbranched modified alkyl alcohol amide is 3 to 7 parts by weight, the content of the polycarboxylic acid water reducer is 10 to 15 parts by weight, and the content of water is 40 to 70 parts by weight; Preferably, the mass ratio of the surfactant to the modified plant protein is (1-1.5):

1.

3. The concrete foaming agent according to claim 1, characterized in that During the preparation of the modified vegetable protein, the alkaline substance exists in the form of an alkaline solution; Preferably, the concentration of the alkaline substance in the alkaline solution is 0.05 to 0.1 mol / L; Preferably, the mass ratio of the plant protein to the alkaline solution is 1:(10-50).

4. The concrete foaming agent according to claim 3, characterized in that The plant protein is selected from at least one of tea cake protein, soy protein, pea protein and brown rice protein; Preferably, the alkaline substance is selected from at least one of sodium hydroxide, potassium hydroxide and ammonium hydroxide.

5. The concrete foaming agent according to claim 1, characterized in that The temperature of the modification reaction is 30-50° C. and the time is 8-10 hours.

6. The concrete foaming agent according to claim 1, characterized in that The melt polymerization reaction is carried out in the presence of a catalyst; Preferably, the mass ratio of the cyclic fatty acid, alcohol amide, branched monomer and catalyst is 1:(1-3):(0.8-1.0):(0.5-0.8).

7. The concrete foaming agent according to claim 6, characterized in that The cyclic fatty acid is selected from at least one of cyclohexanecarboxylic acid, cyclopentanecarboxylic acid, cycloheptanecarboxylic acid, cyclobutanecarboxylic acid and cyclooctanecarboxylic acid; Preferably, the alkanolamine is selected from at least one of triethanolamine, diethanolamine, triisopropanolamine and diisopropanolamine; Preferably, the branching monomer is selected from at least one of chitosan, pentaerythritol and sorbitol; Preferably, the catalyst is selected from at least one of dipotassium hydrogen phosphate, trifluoromethanesulfonic acid, p-toluenesulfonic acid, and dibutyltin dilaurate; Preferably, the temperature of the melt polymerization reaction is 160-180° C. and the time is 6-8 hours.

8. The concrete foaming agent according to claim 1, characterized in that The surfactant is selected from at least one of potassium cocoate soap, lauryl amide propyl dimethyl tertiary amine, erucic acid amide propyl dimethyl tertiary amine, oleic acid amide propyl hydroxysulfobetaine, sodium dodecylbenzene sulfonate, sodium lauryl sulfate, sodium fatty acid methyl ester sulfonate, and sodium α-olefin sulfonate; Preferably, the number average molecular weight of the polycarboxylate water-reducing agent is 30,000 to 50,000 mol / L.

9. The method for preparing a concrete foaming agent according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: uniformly mixing composite foaming components, hyperbranched modified alkyl alcohol amide, polycarboxylic acid water reducing agent and water to obtain a concrete foaming agent.

10. Use of the concrete foaming agent according to any one of claims 1 to 8 in building materials.

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