Tea seed cake-based foam concrete foaming agent and preparation method thereof

Abstract

The invention relates to a tea seed cake-based foam concrete foaming agent and a preparation method thereof, and the tea seed cake-based foam concrete foaming agent is prepared from the following raw materials in parts by weight: 10-20 parts of tea seed cake; 1-5 parts of a composite early strength agent; 0.5-3 parts of a crystal nucleus early strength agent; 1-2 parts of a foam stabilizer; 2-8 parts of a surfactant; 1-3 parts of a preservative; and water. The tea seed cake-based foam concrete foaming agent provided by the invention shows excellent foaming performance and good stability, and can be used for preparing foam concrete. According to the invention, the composite early strength agent is added into the tea seed cake-based foam concrete foaming agent, and the early strength component in the composite early strength agent enables the foam concrete to obtain higher strength in a short time, so that the construction period is greatly shortened. The tea seed meal is used as the main raw material, so that the performance of the tea seed meal-based foam concrete foaming agent is improved, the effective utilization of wastes (tea seed meal) is realized, and the production cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of concrete admixtures, in particular to a tea seed meal-based foam concrete foaming agent and a preparation method thereof. Background Art

[0002] With the rapid development of social economy, resource shortage and environmental pollution problems are becoming increasingly prominent, and the construction industry has an increasing demand for energy conservation, emission reduction and green environmental protection materials. As an important green building material, foam concrete has gradually become an ideal substitute for traditional insulation materials due to its excellent properties such as sound absorption and sound insulation, thermal insulation, fire retardancy, etc. Foam concrete not only has low biological toxicity and good durability, but also has the advantages of light weight, earthquake resistance, economy and environmental protection, which meets the development requirements of green buildings.

[0003] Foamed concrete is prepared by mixing a foaming agent with concrete. Existing foaming agents mainly include surfactants, animal proteins, and composite foaming agents. Although plant protein foaming agents have good development prospects due to their wide source of raw materials, low cost, and environmental friendliness, they have low foaming ability and poor anti-corrosion performance, and are still difficult to meet the requirements of large-scale industrial applications. Therefore, developing a foaming agent with excellent performance and low cost has become the research focus of the industry. Summary of the invention

[0004] Based on this, it is necessary to provide a tea seed meal-based foam concrete foaming agent with excellent performance and low cost and a preparation method thereof.

[0005] To achieve the above object, the present invention provides a technical solution:

[0006] A tea seed meal-based foamed concrete foaming agent, wherein the raw materials for preparing the tea seed meal-based foamed concrete foaming agent include, by weight:

[0007]

[0008]

[0009] Specifically, in the oil-tea producing areas in southern China, such as Fujian, tea seed meal resources are abundant and low in cost. Tea seed meal is rich in protein and is suitable as a raw material for environmentally friendly foaming agents. Using tea seed meal to prepare foaming agents can not only reduce costs, but also achieve resource recycling.

[0010] There are some technical difficulties in using tea seed meal as a foaming agent raw material, mainly including the following aspects:

[0011] 1. Protein content and purity

[0012] Although the protein content in tea seed meal is relatively high, not all of it is an effective foaming ingredient. The oil, carbohydrates and other impurities remaining in the oil extraction process may affect the foaming performance.

[0013] Therefore, in some embodiments, the tea seed meal needs to be purified, and the processing steps include:

[0014] (1) Remove impurities:

[0015] Remove non-plant impurities (such as stones, metal chips, etc.) from tea seed meal to ensure the safety of subsequent processing and product quality.

[0016] (2) Crushing:

[0017] Crushing large pieces of tea seed cake into fine powder increases its specific surface area, which is beneficial to the dissolution of active ingredients in the subsequent extraction process.

[0018] (3) Purification:

[0019] Use alkaline solution to adjust the pH value to 8-11, react at 30-60°C for 50-80 minutes to fully dissolve the protein in water to form a protein mother liquor. This step is a key purification process and can effectively separate and concentrate the protein components. Preferably, the alkaline solution includes sodium hydroxide solution or potassium hydroxide aqueous solution.

[0020] (4) Filtration and washing:

[0021] After the reaction is completed, the solids are separated by centrifugation or filtration, and the filtrate is collected as the protein mother liquor; preferably, the precipitate can be washed with water or other appropriate solvents to remove the unreacted alkali solution and other impurities.

[0022] 2. Insufficient foaming ability

[0023] Problem: The foaming ability of plant protein itself is usually weak and it is difficult to meet the standards of cement foaming agent.

[0024] Solution: To make up for this defect, this patent introduces surfactants (such as sodium dodecylbenzene sulfonate), which can significantly reduce the surface tension of the liquid and enhance the foaming effect. At the same time, by optimizing the ratio of surfactant to tea seed meal protein (for example, the mass ratio used in the embodiment is (0.5-0.8):1), the foaming strength is further improved.

[0025] 3. Poor foam stability

[0026] Problem: Even if enough foam can be produced, it will not meet the needs of practical applications if the foam is unstable and easily breaks.

[0027] Solution: This patent adds a foam stabilizer (such as dodecyl dimethylamine oxide), which can increase the elasticity and viscosity of the foam liquid film, prevent the foam from breaking, and make the pore distribution more uniform. In addition, a crystal nucleus early strength agent (such as calcium sulfate whisker or wollastonite powder) is added, which forms tiny crystals during the concrete curing process, accelerates the cement hydration reaction, thereby improving the early strength of the foam concrete and indirectly enhancing the stability of the foam.

[0028] 4. Poor anti-corrosion performance

[0029] Problem: Tea seed meal extract may deteriorate during storage, resulting in decreased foaming performance.

[0030] Solution: In order to avoid this problem, this patent adds an appropriate amount of preservatives (such as kason, isothiazolinone and sodium hydroxymethylglycinate) to the formula. These preservatives can inhibit the growth of microorganisms for a long time and maintain the stability and effectiveness of the foaming agent.

[0031] 5. Compatibility and adaptability

[0032] Problem: There may be compatibility issues between different types of cement and other additives, affecting the performance of the final product.

[0033] Solution: This patent ensures good compatibility between the foaming agent and general cement paste by carefully selecting and blending the proportions of each component. In particular, multiple experimental verifications have been conducted to meet the needs of different application scenarios, proving that the foaming agent is suitable for a variety of foam concrete projects, including wall insulation systems, roof insulation layers and other fields.

[0034] The invention introduces early strength components (such as triisopropanolamine and sodium nitrite) and foam stabilizers (such as dodecyl dimethyl amine oxide) into a tea seed meal-based foaming agent, thereby significantly improving the early strength and foam stabilizing performance, thereby solving the problems of low foaming strength and poor stability of the existing foaming agent.

[0035] In one embodiment, the mass fraction of water is 100 to 150 parts.

[0036] In one embodiment, the composite early strength agent includes a mixture of triisopropanolamine and sodium nitrite.

[0037] In one embodiment, the mass ratio of the triisopropanolamine to the sodium nitrite is (5-2):1, preferably 3:1.

[0038] In one embodiment, the crystal nucleus early strength agent includes at least one of a liquid crystal nucleus early strength agent, a nano seed crystal early strength agent and a nano cement-based crystal nucleus early strength agent.

[0039] In one embodiment, the foam stabilizer includes at least one of sodium lauroyl sarcosinate and dodecyl dimethyl amine oxide.

[0040] In one embodiment, the surfactant includes at least one of sodium dodecylbenzene sulfonate, sodium laurate and sodium dodecyl sulfate.

[0041] In one embodiment, the preservative includes at least one of kasone, isothiazolinone and sodium hydroxymethylglycinate.

[0042] The present invention also provides a method for preparing a tea seed meal-based foamed concrete foaming agent, comprising the steps of:

[0043] S100, mixing tea seed meal and water, adjusting the pH value to 8-11, stirring for reaction, filtering the reaction solution after the reaction is completed, and obtaining the filtrate as the foaming agent mother solution;

[0044] Specifically, the purpose of step S100 is to mix tea seed meal with water, and in the process of adjusting the pH value to 8-11, in some embodiments, alkali solution is added to adjust the pH value. The added alkali solution not only dissolves the protein in the tea seed meal, but also triggers a series of chemical and physical changes. The following is a detailed explanation:

[0045] After adding alkali solution (such as sodium hydroxide or potassium hydroxide), the pH value of the solution increases to an alkaline environment (pH 8-11). Under this condition, the protein in the tea seed meal will dissolve because most plant proteins have a high solubility in an alkaline environment.

[0046] At the same time, alkaline conditions will also cause a certain degree of protein denaturation. Denaturation refers to the destruction of secondary bonds (such as hydrogen bonds, hydrophobic interactions, etc.) within protein molecules, causing the protein to change from its natural folded structure to a looser state. This denaturation helps the protein to dissolve better in water and form a stable colloidal solution.

[0047] At higher pH values, some proteins may undergo hydrolysis, that is, the peptide bonds in the protein chain are broken, generating smaller polypeptide fragments or even amino acids. This process can increase the content of soluble nitrogen compounds in the solution, further increasing the concentration of the active ingredient of the foaming agent.

[0048] The degree of hydrolysis depends on the reaction time and temperature. Usually, keeping the temperature at 30℃ to 60℃ for 50min to 80min is enough to hydrolyze the protein moderately without excessive degradation, thereby retaining sufficient macromolecular structure to maintain good foaming properties.

[0049] Alkaline conditions can also help remove some non-protein components in tea seed meal, such as lipids, cellulose and other polysaccharides. If these impurities are not effectively removed, they may affect the quality and stability of the foaming agent.

[0050] For example, residual oil can easily saponify into soap-like substances in an alkaline environment, making it easier to separate them by centrifugation or filtration. Some polysaccharides will dissolve or swell under alkaline conditions, making them easier to separate from protein solutions.

[0051] In addition to acting directly on the protein itself, the lye solution also improves the solubility and dispersibility of the entire system. It reduces the surface tension of the solution, making it easier to disperse the tea seed meal particles and promoting the effective extraction of the protein.

[0052] In addition, alkaline conditions also help to break the electrostatic repulsion between tea seed meal particles, making them more evenly distributed in the water, thereby improving the extraction efficiency of protein.

[0053] S200, adding a surfactant, a foam stabilizer, a composite early strength agent, a preservative, and a crystal nucleus early strength agent to the foaming agent mother solution, stirring and mixing the mixture evenly, and obtaining a tea seed meal-based foam concrete foaming agent.

[0054] In one embodiment, in step S100, the reaction temperature of the stirring reaction is 30°C to 60°C.

[0055] In one embodiment, in step S100, the stirring reaction time is 50 min to 80 min.

[0056] In one embodiment, in step S100, an alkaline regulator is used to adjust the pH value to 8-11.

[0057] In one embodiment, in step S100, the alkaline regulator includes an aqueous sodium hydroxide solution or an aqueous potassium hydroxide solution.

[0058] Beneficial effects of the present invention:

[0059] The tea seed meal-based foamed concrete foaming agent provided by the invention exhibits excellent foaming performance and good stability, and can be used for preparing foamed concrete.

[0060] The invention adds a composite early strength agent to a tea seed meal-based foamed concrete foaming agent, wherein the early strength component enables the foamed concrete to obtain a higher strength in a short time, thereby greatly shortening the construction period.

[0061] In addition, using tea seed meal as the main raw material not only improves the performance of tea seed meal-based foam concrete foaming agent, but also realizes the effective utilization of waste (tea seed meal) and reduces production costs. DETAILED DESCRIPTION

[0062] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0063] In the examples, the test methods used are conventional methods unless otherwise specified, and the materials, reagents, etc. used are all commercially available unless otherwise specified.

[0064] Example 1

[0065] S100, weigh 20 parts of tea seed meal and add them into a reactor containing 100 parts of water, add 10 parts of 30% sodium hydroxide aqueous solution under stirring, adjust the pH value to 10, raise the temperature to 60°C and continue the reaction for 80 minutes, and centrifuge to obtain a foaming agent mother liquor;

[0066] S200, add 8 parts of sodium dodecylbenzene sulfonate, 1 part of sodium lauroyl sarcosinate, 3 parts of a mixture of triisopropanolamine and sodium nitrite, and 1 part of kason to the foaming agent mother liquor, stir evenly to obtain a preliminary mixed solution; then, add 1.5 parts of calcium sulfate whiskers as a crystal nucleus early strength agent, stir evenly again to obtain a tea seed meal-based foam concrete foaming agent.

[0067] The test steps were carried out in accordance with the requirements of standard JC / T2199-20013 "Foaming Agents for Foamed Concrete". The test results showed that the foaming height of the foaming agent reached 230mm, the foam stability time exceeded 10 hours, no deterioration was found in three months, and the compressive strength of the prepared foamed concrete could reach more than 4.8MPa at the age of 7 days, showing excellent early strength performance.

[0068] Example 2

[0069] S100, weigh 10 parts of tea seed meal and add them into a reactor containing 100 parts of water, add 11 parts of 30% sodium hydroxide aqueous solution under stirring, adjust the pH value to 11, raise the temperature to 40°C and continue the reaction for 50 minutes, and centrifuge to obtain a foaming agent mother liquor.

[0070] S200, add 2 parts of sodium dodecylbenzene sulfonate, 1 part of dodecyl dimethyl amine oxide, 3 parts of a mixture of triisopropanolamine and sodium nitrite, and 1 part of s-triazine to the foaming agent mother liquor, stir evenly to obtain a preliminary mixed solution; then, add 2 parts of nano cement-based crystal nucleus early strength agent, stir evenly again to obtain a tea seed meal-based foam concrete foaming agent.

[0071] After testing, the foaming height of the foaming agent reached 200mm, the foam stability time exceeded 13.5 hours, and no deterioration was found in three months. The compressive strength of the prepared foamed concrete could reach more than 4.5MPa at the age of 7 days, and it also showed good early strength performance.

[0072] Comparative Example 1

[0073] Commercially available cement foaming agent F-1 (model: foaming agent AC).

[0074] Comparative Example 2

[0075] The other steps are the same as those in Example 1, except that the foaming agent mother solution in step S100 is replaced with a commercially available foaming agent mother solution F-1 of equal amount and concentration.

[0076] Comparative Example 3

[0077] The other steps are the same as those in Example 1, except that the composite early strength agent (triisopropanolamine and sodium nitrite) is not added in step S200, and the amount of water is changed so that the solid content of the tea seed meal-based foamed concrete foaming agent prepared in Comparative Example 3 is the same as that in Example 1.

[0078] Comparative Example 4

[0079] The other steps are the same as those in Example 1, except that triisopropanolamine in the composite early strength agent is not added in step S200, and the amount of water is changed so that the solid content of the tea seed meal-based foamed concrete foaming agent prepared in Comparative Example 4 is the same as that in Example 1.

[0080] Comparative Example 5

[0081] The other steps are the same as those in Example 1, except that sodium nitrite in the composite early strength agent is not added in step S200, and the amount of water is changed so that the solid content of the tea seed meal-based foamed concrete foaming agent prepared in Comparative Example 5 is the same as that in Example 1.

[0082] Comparative Example 6

[0083] The other steps are the same as those in Example 1, except that no crystal nucleus early strength agent is added in step S200, and the amount of water is changed so that the solid content of the tea seed meal-based foamed concrete foaming agent prepared in Comparative Example 5 is the same as that in Example 1.

[0084] Comparative Example 7

[0085] The other steps are the same as those in Example 1, except that dodecyl dimethyl ammonium chloride is not added in step S200, and the amount of water is changed so that the solid content of the tea seed meal-based foamed concrete foaming agent prepared in Comparative Example 5 is the same as that in Example 1.

[0086] According to the provisions of JC / T2199-2013 "Foamed Adhesive for Foamed Concrete", the foaming multiple, 1h settlement distance, 1h water seepage rate, and compressive strength ratio tests were carried out. The test results are shown in Table 1.

[0087] Table 1 Test results

[0088]

[0089] It can be seen from the experimental results in Table 1 that the foaming agents of Examples 1 to 2 are better than those of the control example in terms of foaming multiple, 1h settlement distance and 1h water bleeding rate, foam concrete slurry settlement rate and 7d and 28d strength, and all three groups of samples meet the technical requirements of the first-class products in the standard; it can be seen that the present invention has foam stabilization performance and early strength performance that are significantly better than those of commercially available foaming agents.

[0090] It is known to those skilled in the art that when the technical solution of the present invention is changed within the following scope, a technical solution that is the same as or similar to the above embodiment can still be obtained and still falls within the protection scope of the present invention.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, 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 tea seed meal-based foamed concrete foaming agent, characterized in that: The raw materials for preparing the tea seed meal-based foamed concrete foaming agent include, by weight:

2. The tea seed meal-based foamed concrete foaming agent according to claim 1, characterized in that: The composite early strength agent comprises a mixture of triisopropanolamine and sodium nitrite.

3. The tea seed meal-based foamed concrete foaming agent according to claim 2, characterized in that: The mass ratio of the triisopropanolamine to the sodium nitrite is (5-2):

1.

4. The tea seed meal-based foamed concrete foaming agent according to claim 1, characterized in that: The crystal nucleus early strength agent includes at least one of a liquid crystal nucleus early strength agent, a nano crystal seed early strength agent and a nano cement-based crystal nucleus early strength agent.

5. The tea seed meal-based foamed concrete foaming agent according to claim 1, characterized in that: The foam stabilizer includes at least one of sodium lauroyl sarcosinate and dodecyl dimethyl amine oxide.

6. The tea seed meal-based foamed concrete foaming agent according to claim 1, characterized in that: The surfactant includes sodium dodecylbenzene sulfonate.

7. The tea seed meal-based foamed concrete foaming agent according to claim 1, characterized in that: The preservative includes at least one of kasone, isothiazolinone and sodium hydroxymethylglycinate.

8. A method for preparing a tea seed meal-based foamed concrete foaming agent as claimed in any one of claims 1 to 7, characterized in that: Includes steps: Mix tea seed meal and water, adjust the pH value to 8-11, stir and react, filter the reaction liquid after the reaction is completed, and the obtained filtrate is the foaming agent mother liquid; Add a surfactant, a foam stabilizer, a composite early strength agent, a preservative, and a crystal nucleus early strength agent into the foaming agent mother solution, stir and mix evenly, and obtain a tea seed meal-based foam concrete foaming agent.

9. The method for preparing the tea seed meal-based foamed concrete foaming agent according to claim 8, characterized in that: The reaction temperature of the stirring reaction is 30°C to 60°C.

10. The method for preparing the tea seed meal-based foamed concrete foaming agent according to claim 8, characterized in that: The reaction time of the stirring reaction is 50 min to 80 min.

Images