Environment-friendly formula preparation method of polymer concrete release agent

Abstract

The invention relates to the technical field of building materials, and discloses an environment-friendly formula preparation method of a high-molecular concrete release agent, which is prepared from the following raw materials in parts by mass: 30 to 40 parts of high-molecular polymer, 15 to 20 parts of vegetable fat, 8 to 12 parts of environment-friendly solvent, 5 to 8 parts of nano silicon dioxide, 3 to 5 parts of emulsifier, 2 to 4 parts of modified starch, 1 to 2 parts of preservative and 20 to 30 parts of deionized water. The preparation method comprises the following steps: modifying starch, and sequentially carrying out acetylation reaction, cationization reaction and maleic anhydride grafting reaction, so as to obtain the modified starch with hydrophilicity and adsorbability. The modified starch has a synergistic effect with a high-molecular polymer and nano silicon dioxide, so that a uniform and compact isolating membrane can be formed on the surface of concrete, the lubricity and isolation performance of the release agent are remarkably improved, adhesion of the concrete and a template is effectively avoided, and it is guaranteed that the surface of a concrete member is flat and smooth. And meanwhile, by introducing the modified starch, the biodegradability of the release agent is enhanced, and the problem of residue pollution of a traditional release agent is solved.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, specifically to an environmentally friendly formulation preparation method for a polymer concrete release agent. Background Technology

[0002] In the field of modern construction engineering, concrete release agents are key auxiliary materials that ensure the smooth release of concrete components from formwork and guarantee the surface quality of the components. Their application runs through the entire construction process of various building structures, from beams, columns, and floor slabs in buildings to large-scale projects such as bridges and tunnels. High-quality release agents can not only reduce formwork wear and lower construction costs, but also effectively improve the appearance and internal quality of concrete components.

[0003] Currently, there are many types of release agents on the market. Traditional release agents mostly use mineral oil and petroleum derivatives as their main components. While these release agents can generally meet the demolding requirements in practical applications, there are still some areas for improvement from the perspectives of environmental protection and long-term use. For example, some mineral oil-based release agents have relatively weak biodegradability, which may lead to some accumulation in the environment after long-term use. Furthermore, some release agents add highly volatile components to improve short-term demolding effects. These components are released during construction and may have a certain impact on the construction environment.

[0004] Meanwhile, with the deepening of the green building concept, the construction industry has increasingly higher requirements for the environmental performance of materials. Traditional release agents can no longer fully meet the environmental standards of the new era. Furthermore, in some special construction environments, such as high temperature and humidity or low temperature and dry environments, the stability of some existing release agents may be affected, potentially leading to fluctuations in release performance. Based on this, the present invention provides an environmentally friendly formulation preparation method for a polymeric concrete release agent. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an environmentally friendly formulation preparation method for a polymer concrete release agent, solving the problems mentioned in the background section.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: a polymer concrete release agent, comprising the following raw materials in parts by weight: 30-40 parts of polymer, 15-20 parts of vegetable oil, 8-12 parts of environmentally friendly solvent, 5-8 parts of nano silica, 3-5 parts of emulsifier, 2-4 parts of modified starch, 1-2 parts of preservative, and 20-30 parts of deionized water;

[0007] The modified starch is prepared by the following steps:

[0008] Step 1: Mix starch, acetic anhydride and pyridine in a container, stir well, raise the temperature of the system to 40-50℃, and react for 3 hours to obtain acetylated starch intermediate;

[0009] Step 2: Mix acetylated starch intermediate, 3-chloro-2-hydroxypropyltrimethylammonium chloride, and sodium hydroxide solution, and react at 50-60℃ for 4 hours to obtain cationic starch intermediate;

[0010] Step 3: Mix cationic starch intermediate, maleic anhydride, benzoyl peroxide, and ethanol solution, heat to 60-70℃ and react for 2.5 h, cool, wash and dry to obtain the modified starch.

[0011] Preferably, the ratio of starch, acetic anhydride, and pyridine used in step 1 is 10 mol: 3-4 mol: 5-6 mol.

[0012] Preferably, in step 2, the mass concentration of the sodium hydroxide solution is 8-10%, and the ratio of the amount of acetylated starch intermediate, 3-chloro-2-hydroxypropyltrimethylammonium chloride, and sodium hydroxide solution used is 10 mol: 5-6 mol: 3-4 mol.

[0013] Preferably, in step 3, the volume fraction of the ethanol solution is 70-80%, the ratio of cationic starch intermediate, maleic anhydride, and benzoyl peroxide used is 10 mol: 2-3 mol: 0.5-1 mol, and the volume of the ethanol solution used is 8-10 mL.

[0014] Preferably, the polymer is at least one of polyvinyl alcohol and polyethylene glycol, wherein the degree of polymerization of polyvinyl alcohol is 1700-1800 and the degree of alcoholysis is 88-90%, and the molecular weight of polyethylene glycol is 400-600.

[0015] Preferably, the environmentally friendly solvent is at least one of ethylene glycol ethyl ether and propylene glycol methyl ether.

[0016] Preferably, the emulsifier is at least one of fatty acid sucrose ester and polyoxyethylene sorbitan fatty acid ester, wherein the HLB value of fatty acid sucrose ester is 11-13 and the HLB value of polyoxyethylene sorbitan fatty acid ester is 14-16.

[0017] Preferably, the preservative is at least one of sodium benzoate and potassium sorbate.

[0018] An environmentally friendly formulation preparation method for a polymer concrete release agent includes the following steps:

[0019] Step 1: Weigh out the raw materials according to the following proportions by weight: 30-40 parts of polymer, 15-20 parts of vegetable oil, 8-12 parts of environmentally friendly solvent, 5-8 parts of nano silica, 3-5 parts of emulsifier, 2-4 parts of modified starch, 1-2 parts of preservative, and 20-30 parts of deionized water.

[0020] The second step is to add the polymer and environmentally friendly solvent into the reaction vessel and heat it to 50-60℃ while stirring to dissolve.

[0021] Third step: Add vegetable oil and emulsifier to the solution in the second step, and stir and emulsify at 40-50℃ for 30-40 minutes.

[0022] Step 4: Add nano-silica, modified starch, preservative and deionized water, continue stirring for 20-30 minutes, and cool to room temperature to obtain a polymer concrete release agent.

[0023] Preferably, the stirring speed in the third step is 300-500 r / min.

[0024] This invention provides an environmentally friendly formulation preparation method for a polymer concrete release agent. It has the following beneficial effects:

[0025] 1. This invention uses polymer, vegetable oil, environmentally friendly solvent, nano-silica, emulsifier, modified starch, preservative, and deionized water as raw materials. Through reasonable formulation design and preparation process, a polymeric concrete release agent is obtained. In the preparation process, the polymer is first dissolved in an environmentally friendly solvent, and then vegetable oil, emulsifier, nano-silica, and other raw materials are added sequentially and mixed. The process steps are simple and controllable, requiring no high temperature or high pressure conditions, making it easy to scale up production. Furthermore, the entire preparation process produces no toxic or harmful substances, meeting environmental protection production requirements.

[0026] 2. This invention modifies starch through sequential acetylation, cationization, and maleic anhydride grafting to obtain a modified starch with both hydrophilic and adsorption properties. This modified starch, in synergy with polymers and nano-silica, forms a uniform and dense release film on the concrete surface, significantly improving the lubricity and release properties of the release agent, effectively preventing adhesion between concrete and formwork, and ensuring a smooth and flat surface for the concrete component. Simultaneously, the introduction of modified starch enhances the biodegradability of the release agent, solving the problem of residual pollution associated with traditional release agents.

[0027] 3. This invention uses vegetable oils and environmentally friendly solvents to replace traditional mineral oils and toxic solvents, reducing the release of volatile organic compounds and minimizing harm to the construction environment and human health. The addition of nano-silica not only improves the wear resistance and water resistance of the release agent but also enhances the structural stability of the release film through a filling effect, extending the service life of the template. Furthermore, the synergistic effect of the various raw material components ensures that the release agent maintains good stability under both low and high temperature environments, making it widely applicable. Detailed Implementation

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0029] Example 1

[0030] A modified starch is prepared by the following steps:

[0031] Step 1: Mix 10 mol starch, 3 mol acetic anhydride and 5 mol pyridine in a three-necked flask, attach a condenser and a thermometer, turn on magnetic stirring (200 r / min), raise the system temperature to 40℃, and react at 40℃ for 3 h. After the reaction is complete, add distilled water to the flask and wash it 3 times. After centrifugation and drying, the acetylated starch intermediate is obtained.

[0032] Step 2: Mix 10 mol of acetylated starch intermediate, 5 mol of 3-chloro-2-hydroxypropyltrimethylammonium chloride, and 3 mol of 8% sodium hydroxide solution in a three-necked flask. Turn on the magnetic stirrer (250 r / min), heat to 50℃ and react for 4 h. After the reaction is completed, adjust the pH to neutral with dilute hydrochloric acid, wash and dry to obtain cationic starch intermediate.

[0033] Step 3: Mix 10 mol of cationic starch intermediate, 2 mol of maleic anhydride, 0.5 mol of benzoyl peroxide, and 8 mL of 70% ethanol solution in a three-necked flask, turn on magnetic stirring (300 r / min), heat to 60℃ and react for 2.5 h, cool and wash three times with anhydrous ethanol, and vacuum dry to obtain the modified starch.

[0034] Example 2

[0035] A modified starch is prepared by the following steps:

[0036] Step 1: Mix 10 mol starch, 3.5 mol acetic anhydride and 5.5 mol pyridine in a three-necked flask, attach a condenser and a thermometer, turn on the magnetic stirrer (200 r / min), raise the system temperature to 45℃, and react at 45℃ for 3 h. After the reaction is complete, add distilled water to the flask and wash it 3 times. After centrifugation and drying, the acetylated starch intermediate is obtained.

[0037] Step 2: Mix 10 mol of acetylated starch intermediate, 5.5 mol of 3-chloro-2-hydroxypropyltrimethylammonium chloride, and 3.5 mol of 9% sodium hydroxide solution in a three-necked flask. Turn on the magnetic stirrer (250 r / min), heat to 55℃ and react for 4 h. After the reaction is completed, adjust the pH to neutral with dilute hydrochloric acid, wash and dry to obtain cationic starch intermediate.

[0038] Step 3: Mix 10 mol of cationic starch intermediate, 2.5 mol of maleic anhydride, 0.75 mol of benzoyl peroxide, and 9 mL of 75% ethanol solution in a three-necked flask, turn on magnetic stirring (300 r / min), heat to 65℃ and react for 2.5 h, cool and wash three times with anhydrous ethanol, and vacuum dry to obtain the modified starch.

[0039] Example 3

[0040] A modified starch is prepared by the following steps:

[0041] Step 1: Mix 10 mol starch, 4 mol acetic anhydride and 6 mol pyridine in a three-necked flask, attach a condenser and a thermometer, turn on magnetic stirring (200 r / min), raise the system temperature to 50℃, and react at 50℃ for 3 h. After the reaction is complete, add distilled water to the flask and wash it 3 times. After centrifugation and drying, the acetylated starch intermediate is obtained.

[0042] Step 2: Mix 10 mol of acetylated starch intermediate, 6 mol of 3-chloro-2-hydroxypropyltrimethylammonium chloride, and 4 mol of 10% sodium hydroxide solution in a three-necked flask, turn on magnetic stirring (250 r / min), heat to 60℃ and react for 4 h. After the reaction is complete, adjust the pH to neutral with dilute hydrochloric acid, wash and dry to obtain cationic starch intermediate;

[0043] Step 3: Mix 10 mol of cationic starch intermediate, 3 mol of maleic anhydride, 1 mol of benzoyl peroxide, and 10 mL of 80% ethanol solution in a three-necked flask, turn on magnetic stirring (300 r / min), heat to 70℃ and react for 2.5 h, cool and wash three times with anhydrous ethanol, and vacuum dry to obtain the modified starch.

[0044] Comparative Example 1

[0045] This comparative example uses unmodified native starch.

[0046] The modified starches of Examples 1-3 and the native starch of Comparative Example 1 were subjected to performance tests. Equal masses of samples were weighed and mixed with water to prepare 5% solutions. Their emulsification stability (separation rate after standing for 24 hours) and adsorption performance (adsorption rate of residual substances on concrete surface) were tested. The results are shown in Table 1:

[0047] Table 1

[0048] Item Emulsion delamination rate (%) Surface residual adsorption rate (%) Example 1 3.2 92.5 Example 2 2.8 93.1 Example 3 2.5 94.3 Comparative Example 1 15.6 68.7

[0049] As shown in Table 1, the modified starch of the present invention exhibits significantly better emulsification stability and adsorption performance than the unmodified starch, and can better synergistically improve the performance of the release agent.

[0050] Example 4

[0051] A polymeric concrete release agent comprises the following raw materials in parts by weight: 30 parts polyvinyl alcohol (degree of polymerization 1700, degree of hydrolysis 88%), 15 parts soybean oil, 8 parts ethylene glycol ethyl ether, 5 parts nano silica, 3 parts fatty acid sucrose ester (HLB11), 2 parts modified starch of Example 1, 1 part sodium benzoate, and 20 parts deionized water.

[0052] Its preparation method includes the following steps:

[0053] Step 1: Weigh each raw material according to the above-mentioned mass proportions;

[0054] Step 2: Add polyvinyl alcohol and ethylene glycol ethyl ether to the reaction vessel, heat to 50°C, and stir (200 r / min) to dissolve for 40 min;

[0055] Third step: Add soybean oil and fatty acid sucrose ester to the solution from the second step, and stir and emulsify at 300 r / min for 30 min at 40℃.

[0056] Step 4: Add nano-silica, the modified starch from Example 1, sodium benzoate and deionized water, continue stirring for 20 minutes, and cool to room temperature to obtain the final product.

[0057] Example 5

[0058] A polymeric concrete release agent comprises the following raw materials in parts by weight: 35 parts polyethylene glycol (molecular weight 400), 18 parts rapeseed oil, 10 parts propylene glycol methyl ether, 6.5 parts nano silica, 4 parts polyoxyethylene sorbitan fatty acid ester (HLB14), 3 parts modified starch of Example 2, 1.5 parts potassium sorbate, and 25 parts deionized water.

[0059] Its preparation method includes the following steps:

[0060] Step 1: Weigh each raw material according to the above-mentioned mass proportions;

[0061] Step 2: Add polyethylene glycol and propylene glycol methyl ether to the reaction vessel, heat to 55°C, and stir (220 r / min) to dissolve for 35 min;

[0062] Third step: Add rapeseed oil and polyoxyethylene sorbitan fatty acid ester to the solution from the second step, and stir and emulsify at 400 r / min for 35 min at 45℃.

[0063] Step 4: Add nano-silica, the modified starch from Example 2, potassium sorbate, and deionized water, continue stirring for 25 minutes, and cool to room temperature to obtain the final product.

[0064] Example 6

[0065] A polymeric concrete release agent comprises the following raw materials in parts by weight: 40 parts of polyvinyl alcohol-polyethylene glycol compound (mass ratio 1:1), 20 parts of palm oil, 12 parts of propylene glycol methyl ether, 8 parts of nano silica, 5 parts of fatty acid sucrose ester-polyoxyethylene sorbitan ester compound (mass ratio 1:1), 4 parts of modified starch from Example 3, 2 parts of sodium benzoate-potassium sorbate compound (mass ratio 2:1), and 30 parts of deionized water;

[0066] Its preparation method includes the following steps:

[0067] Step 1: Weigh each raw material according to the above-mentioned mass proportions;

[0068] Step 2: Add the compounded polymer and propylene glycol methyl ether to the reaction vessel, heat to 60°C, and stir (250 r / min) to dissolve for 30 min;

[0069] Third step: Add palm oil and compound emulsifier to the solution from the second step, and stir and emulsify at 500 r / min for 40 min at 50℃.

[0070] Step 4: Add nano-silica, the modified starch from Example 3, the compound preservative and deionized water, continue stirring for 30 minutes, and cool to room temperature to obtain the final product.

[0071] Comparative Example 2

[0072] A release agent, with the same raw materials and preparation method as in Example 6, but using native starch from Comparative Example 1 instead of the modified starch from Example 3.

[0073] Comparative Example 3

[0074] This comparative example uses a commercially available mineral oil-based release agent.

[0075] The release agents of Examples 4-6 and Comparative Examples 2-3 were subjected to performance tests. Referring to the JC / T949-2005 standard "Release Agents for Concrete Products", their release effect (surface integrity rate), water resistance (release performance retention rate after immersion treatment), and VOC emissions were tested. The results are shown in Table 2.

[0076] Table 2

[0077]

[0078] As shown in Table 2, the release agents of Examples 1-3 of this invention are significantly superior to the comparative examples in terms of overall performance. Key indicators such as the surface integrity rate of concrete components and water resistance are all superior, effectively reducing formwork adhesion problems and ensuring the appearance quality of the components. In terms of environmental protection, VOC emissions are significantly reduced, meeting the requirements of green construction.

[0079] Crucially, the example using modified starch outperformed Comparative Example 2, which did not use modified starch, demonstrating that modified starch plays a vital role in improving the release agent's isolation and stability. This result fully reflects the rationality of the formulation design and the advanced nature of the process in this invention, meeting the demands of construction for efficient and environmentally friendly release materials.

[0080] The present invention provides a detailed description of an environmentally friendly formulation preparation method for a polymer concrete release agent. Specific examples have been used to illustrate the principles and implementation methods of the invention. The descriptions of these embodiments are merely for the purpose of helping to understand the method and core ideas of the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including manufacturing and using any device or system, and implementing any combination method. It should be noted that those skilled in the art can make various improvements and modifications to the invention without departing from its principles. In particular, as long as there is no structural conflict, the features in the embodiments disclosed in this invention can be combined with each other in any way. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A polymeric concrete release agent, characterized in that, The raw materials include the following parts by weight: 30-40 parts of high molecular weight polymer, 15-20 parts of vegetable oil, 8-12 parts of environmentally friendly solvent, 5-8 parts of nano silica, 3-5 parts of emulsifier, 2-4 parts of modified starch, 1-2 parts of preservative, and 20-30 parts of deionized water. The modified starch is prepared by the following steps: Step 1: Mix starch, acetic anhydride and pyridine in a container, stir well, raise the temperature of the system to 40-50℃, and react for 3 hours to obtain acetylated starch intermediate; Step 2: Mix acetylated starch intermediate, 3-chloro-2-hydroxypropyltrimethylammonium chloride, and sodium hydroxide solution, and react at 50-60℃ for 4 hours to obtain cationic starch intermediate; Step 3: Mix cationic starch intermediate, maleic anhydride, benzoyl peroxide, and ethanol solution, heat to 60-70℃ and react for 2.5 h, cool, wash and dry to obtain the modified starch.

2. The polymeric concrete release agent according to claim 1, characterized in that, The ratio of starch, acetic anhydride, and pyridine used in step 1 is 10 mol: 3-4 mol: 5-6 mol.

3. The polymeric concrete release agent according to claim 1, characterized in that, In step 2, the mass concentration of the sodium hydroxide solution is 8-10%, and the ratio of the amount of acetylated starch intermediate, 3-chloro-2-hydroxypropyltrimethylammonium chloride, and sodium hydroxide solution used is 10 mol: 5-6 mol: 3-4 mol.

4. The polymeric concrete release agent according to claim 1, characterized in that, In step 3, the volume fraction of the ethanol solution is 70-80%, and the ratio of cationic starch intermediate, maleic anhydride, and benzoyl peroxide used is 10 mol: 2-3 mol: 0.5-1 mol. The volume of the ethanol solution used is 8-10 mL.

5. The polymeric concrete release agent according to claim 1, characterized in that, The polymer is at least one of polyvinyl alcohol and polyethylene glycol, wherein the degree of polymerization of polyvinyl alcohol is 1700-1800 and the degree of alcoholysis is 88-90%, and the molecular weight of polyethylene glycol is 400-600.

6. The polymeric concrete release agent according to claim 1, characterized in that, The environmentally friendly solvent is at least one of ethylene glycol ethyl ether and propylene glycol methyl ether.

7. The polymeric concrete release agent according to claim 1, characterized in that, The emulsifier is at least one of fatty acid sucrose ester and polyoxyethylene sorbitan fatty acid ester, wherein the HLB value of fatty acid sucrose ester is 11-13 and the HLB value of polyoxyethylene sorbitan fatty acid ester is 14-16.

8. The polymeric concrete release agent according to claim 1, characterized in that, The preservative is at least one of sodium benzoate and potassium sorbate.

9. A method for preparing an environmentally friendly formulation of a polymer concrete release agent according to any one of claims 1-8, characterized in that, Includes the following steps: Step 1: Weigh out the raw materials according to the following proportions by weight: 30-40 parts of polymer, 15-20 parts of vegetable oil, 8-12 parts of environmentally friendly solvent, 5-8 parts of nano silica, 3-5 parts of emulsifier, 2-4 parts of modified starch, 1-2 parts of preservative, and 20-30 parts of deionized water. The second step is to add the polymer and environmentally friendly solvent into the reaction vessel and heat it to 50-60℃ while stirring to dissolve. Third step: Add vegetable oil and emulsifier to the solution in the second step, and stir and emulsify at 40-50℃ for 30-40 minutes. Step 4: Add nano-silica, modified starch, preservative and deionized water, continue stirring for 20-30 minutes, and cool to room temperature to obtain a polymer concrete release agent.

10. The method for preparing an environmentally friendly formula for a polymer concrete release agent according to claim 9, characterized in that, In the third step, the stirring speed is 300-500 r / min.

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