Epoxy cement composite mortar as well as preparation method and application thereof

Abstract

The invention relates to the technical field of building materials, and particularly discloses epoxy cement composite mortar as well as a preparation method and application thereof. The epoxy cement composite mortar comprises a cement-based mortar component and a waterborne epoxy-amine system cross-linked polymer, the cement mortar comprises the following raw materials: Portland cement, medium sand, a filler, polyether polyol, poly (ethylene glycol) methyl ether methacryloyl acid, a defoaming agent and cellulose acetate butyrate. The waterborne epoxy-amine system cross-linked polymer comprises the following raw materials: waterborne epoxy resin, a polyamide curing agent, propylene glycol monomethyl ether and zinc acetylacetonate. The epoxy cement composite mortar obtained in the invention has good flowability and leveling property, can realize self-leveling construction, and has 7d and 28d compressive strength, bonding strength and breaking strength up to 50.1 MPa, 100.4 MPa, 8.1 MPa and 17.5 MPa to the maximum extent, and the strength of the epoxy cement composite mortar is improved.

Description

Technical Field

[0001] The present application relates to the technical field of building materials, and more specifically, to an epoxy cement composite mortar and a preparation method and application thereof. Background Art

[0002] Cement-based mortar, a key component of building materials, is widely used in floor construction, building restoration, and other fields. Conventional cement-based mortar, composed of heterogeneous, multi-component inorganic, brittle materials, is subject to accelerated degradation by corrosive media such as carbon dioxide, water, chloride ions, and sulfates. This results in a short service life and a poor performance in terms of bond strength, compressive strength, flexural strength, impact resistance, and wear resistance, which are no longer sufficient to meet the demands of modern construction.

[0003] To address these shortcomings, prior art has added epoxy copolymers. While this has resulted in some improvement, the strength remains relatively low. Furthermore, the addition of the copolymers reduces the fluidity of the mortar, making it difficult to achieve self-leveling. Therefore, there is an urgent need for an epoxy cement mortar that maintains high strength while also enabling self-leveling. Summary of the Invention

[0004] In order to improve the strength of epoxy cement mortar and realize self-leveling construction of epoxy cement mortar, the present application provides an epoxy cement composite mortar and its preparation method and application.

[0005] In a first aspect, the present application provides an epoxy cement composite mortar, which adopts the following technical solution: An epoxy cement composite mortar comprises a cement-based mortar component and a waterborne epoxy-amine system cross-linked polymer; the mass ratio of the cement-based mortar component to the waterborne epoxy-amine system cross-linked polymer is 1:(3-5); The cement mortar components include the following raw materials in parts by weight: 20-50 parts of Portland cement, 25-40 parts of medium sand with a fineness modulus of 2.6, 40-60 parts of filler, 5-10 parts of polyether polyol, 1-1.2 parts of poly(ethylene glycol) methyl ether methacrylic acid, 0.5-1 part of defoamer, and 0.5-1 part of cellulose acetate butyrate; The waterborne epoxy-amine system cross-linked polymer comprises the following raw materials in parts by weight: 90-100 parts of waterborne epoxy resin, 30-50 parts of polyamide curing agent, 5-15 parts of propylene glycol methyl ether, and 0.1-0.5 parts of zinc acetylacetonate.

[0006] By adopting the above technical solution, medium sand with a fineness modulus of 2.6 is selected to ensure good compatibility with silicate cement and improve density. Polyether polyols have a long-chain molecular structure, which can increase the elasticity of cement mortar, reduce the brittleness of epoxy cement composite mortar after hardening, and improve the strength of epoxy cement composite mortar. Polyether polyols can also improve the bonding strength between epoxy cement composite mortar and the base layer. Poly(ethylene glycol) methyl ether methacrylic acid can prevent cement particles from agglomerating through steric hindrance and electrostatic repulsion, thereby improving the fluidity and construction performance of the mortar, achieving self-leveling, and making the epoxy cement composite mortar more uniform. In addition, poly(ethylene glycol) methyl ether methacrylic acid can optimize the cement hydration process, reduce porosity, and increase the density of the mortar, thereby enhancing compressive and flexural strength. Defoaming agent is added to eliminate stirring bubbles, avoid bubbles hindering molecular contact, and promote cross-linking. Cellulose acetate butyrate is added as a dispersant to improve the uniformity of the epoxy cement composite mortar. Cellulose acetate butyrate can make the epoxy cement composite mortar easier to spread, form a smooth surface, reduce construction defects, prevent delamination and sagging, and improve the stability between the epoxy cement composite mortar and the substrate.

[0007] Polyamide curing agents contain hydrophilic groups in their molecular chains, increasing their reactivity with waterborne epoxy resins. The addition of propylene glycol methyl ether to the waterborne epoxy-amine crosslinking polymer reduces the interfacial tension between the waterborne epoxy resin and the polyamide curing agent, promoting molecular contact between the two and enhancing their crosslinking ability. Zinc acetylacetonate accelerates the reaction between the waterborne epoxy resin and the polyamide curing agent, shortening the curing time and increasing the curing reaction rate. Furthermore, the addition of zinc acetylacetonate improves the heat resistance of epoxy-cement composite mortars, resisting deformation and aging, and increasing their strength.

[0008] Preferably, the cement mortar component raw materials further include 0.5-1.5 parts by weight of nanocellulose and 10-20 parts by weight of slag powder.

[0009] By adopting the above technical solution, nanocellulose can inhibit crack expansion, improve the toughness of epoxy cement composite mortar, and guide the orderly growth of hydration products, while slag micropowder fills micropores and increases the density of CSH gel. The simultaneous addition of nanocellulose and slag micropowder can optimize the pore structure, reduce stress concentration, and thus improve the strength of epoxy cement composite mortar.

[0010] Preferably, the weight ratio of the nanocellulose to the slag powder is 1:(14-18).

[0011] By adopting the above technical solution and adjusting the weight ratio of nanocellulose to slag powder, the strength of epoxy cement composite mortar can be further improved.

[0012] As a preference, the slag powder is prepared by nano-polytetrafluoroethylene coating modification, specifically: Adding nano-polytetrafluoroethylene to water at a solid content of 40-60%, adding alkylphenol polyoxyethylene ether at a concentration of 1-3% of the total mass of the nano-polytetrafluoroethylene, and performing ultrasonic dispersion to obtain a nano-polytetrafluoroethylene dispersion; The nano-polytetrafluoroethylene dispersion is atomized and sprayed onto the surface of slag micropowder with a moisture content of less than 1% at a spray rate of 0.5-1.5 L / min and a spray pressure of 0.2-0.5 MPa. The powder is dried and agglomerates are removed by vibration to obtain modified slag micropowder.

[0013] By adopting this technical solution, nano-PTFE exhibits high strength and wear resistance. By coating and modifying slag micropowder with nano-PTFE, a network structure is formed, which improves the bonding between the raw materials and thus enhances the strength of the epoxy-cement composite mortar. Controlling the spray rate and pressure during the spray coating process further improves the uniformity of the nano-PTFE coating on the slag micropowder surface, thereby further ensuring the strength of the epoxy-cement composite mortar.

[0014] Adding alkylphenol polyoxyethylene ether to the nano-PTFE dispersion can reduce the interfacial tension of the nano-PTFE in water, make water more easily wet the surface of the nano-PTFE, reduce the tendency to agglomerate, and improve the dispersibility of the nano-PTFE in water.

[0015] Preferably, silicon dioxide aerogel particles are added together with the alkylphenol polyoxyethylene ether.

[0016] By adopting the above technical solution, the silica aerogel particles added to the nano-PTFE dispersion have a steric repulsive force, and the silica aerogel particles can be evenly coated on the surface of the nano-PTFE, which can prevent the nano-PTFE from agglomerating and improve the dispersibility of the nano-PTFE in water. In addition, the hydrophilic groups of the alkylphenol polyoxyethylene ether can form a more stable composite structure with the hydroxyl groups of the silica aerogel particles, and the hydrophobic chains of the non-ionic surfactant can further enhance the steric hindrance effect provided by the silica aerogel particles, forming a dispersion system with multiple combinations of steric hindrance, electrostatic repulsion, and steric stability, thereby improving the dispersibility of the nano-PTFE in water, allowing the nano-PTFE to be evenly coated on the surface of the slag micropowder, and further improving the strength of the epoxy cement composite mortar.

[0017] Preferably, the mass ratio of the silica aerogel particles to the alkylphenol polyoxyethylene ether is 1:(5-10).

[0018] By adopting the above technical solution and adjusting the mass ratio of silica aerogel particles to alkylphenol polyoxyethylene ether, the dispersibility of nano-PTFE in the nano-PTFE dispersion can be further improved, and the uniformity of the nano-PTFE-coated slag powder can be improved, thereby further improving the strength of the epoxy cement composite mortar.

[0019] Preferably, the filler may be at least one of quartz powder, talc powder and calcium carbonate.

[0020] In a second aspect, the present application provides a method for preparing any of the above-mentioned epoxy cement composite mortars, which adopts the following technical solution: A method for preparing epoxy cement composite mortar comprises the following steps: uniformly mixing a water-based epoxy resin and a polyamide curing agent, adding propylene glycol methyl ether and zinc acetylacetonate to obtain a water-based epoxy-amine system cross-linked polymer; The cement-based mortar components are evenly mixed according to proportion, and a water-based epoxy-amine system cross-linked polymer is added and stirred to obtain an epoxy cement composite mortar.

[0021] In a third aspect, the present application provides an application of any of the above-mentioned epoxy cement composite mortars.

[0022] In summary, this application includes at least one of the following beneficial technical effects: (1) This application improves the strength of epoxy cement composite mortar by controlling the types and dosages of various raw materials in cement-based mortar components so that the 7d and 28d compressive strength, bonding strength, and flexural strength of epoxy cement composite mortar are 46.3 MPa, 98.3 MPa, 6.2 MPa, and 14.8 MPa, respectively.

[0023] (2) In this application, nanocellulose and slag powder are added to the original cement-based mortar components and the dosage ratio of the two is controlled, so that the 7d and 28d compressive strength, bonding strength and flexural strength of the epoxy cement composite mortar are 47.9-48.5MPa, 98.6-99.0MPa, 6.7-7.0MPa and 15.8-16.2MPa, respectively, thereby further improving the strength of the epoxy cement composite mortar.

[0024] (3) The present application modifies the slag powder and adds silica aerogel particles at the same time as alkylphenol polyoxyethylene ether during the modification process of the slag powder, and controls the ratio of the two, so that the 7d and 28d compressive strength, bonding strength and flexural strength of the epoxy cement composite mortar are 49.5-50.1MPa, 99.8-100.4MPa, 7.8-8.1MPa and 17.2-17.5MPa, respectively, thereby further improving the strength of the epoxy cement composite mortar.

[0025] (4) The epoxy cement composite mortar obtained in this application has a flowability of 145-150 mm in 5 minutes and a flowability of 138-140 mm in 30 minutes. It has good fluidity and leveling properties and can achieve self-leveling construction. DETAILED DESCRIPTION

[0026] The present application is further described in detail below with reference to specific embodiments.

[0027] The following raw materials in this application are all commercially available products, and are intended to fully disclose the raw materials of this application, and should not be understood as having a restrictive effect on the sources of the raw materials. Specifically: silicate cement, specification P.O42.5; filler, talc powder, particle size 100 mesh; polyether polyol, effective substance content is 99%; poly (ethylene glycol) methyl ether methacrylic acid, effective substance content is 99%; alkylphenol polyoxyethylene ether, effective substance content is 99%; defoamer, model YL-805; leveling agent, model RF-7600; cellulose acetate butyrate, effective substance content is 99%; water-based epoxy resin, emulsion with epoxy equivalent of 190; polyamide curing agent, effective substance content is 99%; propylene glycol methyl ether, effective substance content is 99%; zinc acetylacetonate, effective substance content is 99%; nanocellulose, particle size is 20nm; slag micropowder, particle size is 45μm; nano polytetrafluoroethylene, particle size is 200nm; silica aerogel particles, hydrophilic type, model N20, particle size is 100 mesh.

[0028] The following is an example of the preparation of modified slag powder Preparation Example 1 The modified slag powder of Preparation Example 1 was prepared by the following steps: 500 g of nano-polytetrafluoroethylene was added to 1 L of water, 10 g of alkylphenol polyoxyethylene ether was added, and ultrasonic dispersion was performed to obtain a nano-polytetrafluoroethylene dispersion; The nano-polytetrafluoroethylene dispersion is atomized and sprayed onto the surface of slag micropowder with a moisture content of 0.09% at a spray rate of 1 L / min and a spray pressure of 0.3 MPa. The powder is dried and agglomerates are removed by vibration to obtain modified slag micropowder.

[0029] Preparation Example 2 The preparation method of the modified slag micropowder in Preparation Example 2 is different from that in Preparation Example 1 in that 2.5 g of silica aerogel particles are added at the same time as the alkylphenol polyoxyethylene ether, and the remaining steps are the same as those in Preparation Example 1.

[0030] Preparation Examples 3-6 The preparation methods of the modified slag micropowders of Preparation Examples 3-6 are the same as those of Preparation Example 2, except that the amounts of silica aerogel particles used are different, namely 2 g, 1.4 g, 1 g, and 0.9 g, respectively. The remaining steps are the same as those of Preparation Example 1.

[0031] Example 1 The epoxy cement composite mortar of Example 1 is prepared by the following steps: According to the dosage in Table 1, the water-based epoxy resin and the polyamide curing agent were first mixed evenly to obtain a water-based epoxy-amine system cross-linked polymer; According to the dosage in Table 2, the cement-based mortar components were mixed evenly in proportion, and the water-based epoxy-amine system cross-linked polymer was added at a mass ratio of 1:4 between the cement-based mortar components and the water-based epoxy-amine system cross-linked polymer to obtain an epoxy cement composite mortar.

[0032] Examples 2-7 The epoxy cement composite mortars of Examples 2-7 differ from those of Example 1 in that the amounts of the raw materials are different, and the remaining steps are the same as those of Example 1.

[0033] Table 1 Amount of each raw material of cement mortar components (kg) Table 2 Amount of each raw material of waterborne epoxy-amine system cross-linked polymer (kg) Examples 1-7 Waterborne epoxy resin 95 Polyamide curing agent 40 Propylene glycol methyl ether 10 Zinc acetylacetonate 0.3 Examples 8-12 The epoxy cement composite mortars of Examples 8-12 differ from those of Example 6 in that the raw materials of the cement mortar components further include nanocellulose and slag powder, and the specific dosages are shown in Table 3.

[0034] Table 3 Amount of each raw material of cement mortar components (kg) Examples 13-18 The epoxy cement composite mortars of Examples 13-18 differ from Example 10 in that the slag fine powder in the raw materials of the cement mortar components is the modified slag fine powder prepared in Preparation Examples 1-6, and the other raw materials are the same as those in Example 10.

[0035] Comparative Example 1 The epoxy cement composite mortar of Comparative Example 1 differs from that of Example 1 in that no polyether polyol is added to the cement mortar component, and the remaining steps are the same as those of Example 1.

[0036] Comparative Example 2 The epoxy cement composite mortar of Comparative Example 2 differs from that of Example 1 in that poly(ethylene glycol) methyl ether methacrylic acid is not added to the cement mortar component, and the remaining steps are the same as those of Example 1.

[0037] Comparative Example 3 The epoxy cement composite mortar of Comparative Example 3 differs from that of Example 1 in that cellulose acetate butyrate is not added to the cement mortar component, and the remaining steps are the same as those of Example 1.

[0038] Comparative Example 4 The epoxy cement composite mortar of Comparative Example 4 differs from that of Example 1 in that zinc acetylacetonate is not added to the waterborne epoxy-amine system cross-linked polymer, and the remaining steps are the same as those of Example 1.

[0039] The following are application examples of epoxy cement composite mortar Application Example 1 The application method of the epoxy cement composite mortar of Application Example 1 is specifically as follows: the surface of the base concrete is polished and cleaned with clean water to remove pollutants such as slurry and particles on the surface of the base, and then the epoxy cement composite mortar obtained in Example 1 is evenly and evenly applied on the surface of the substrate by rolling. The coating process is carried out without missing any part and the coating is even, so that the primer forms a film on the surface of the base surface and cools and solidifies.

[0040] Application Example 2-18 The application method of the epoxy cement composite mortar of Application Example 2-18 is different from that of Application Example 1 in that the epoxy cement composite mortars are respectively the epoxy cement composite mortars obtained in Examples 2-18, and the remaining steps are the same as those in Application Example 1.

[0041] Application Comparative Examples 1-4 The application method of the epoxy cement composite mortar of Comparative Examples 1-4 is different from that of Application Example 1 in that the epoxy cement composite mortars are respectively the epoxy cement composite mortars obtained in Comparative Examples 1-4, and the remaining steps are the same as those in Application Example 1.

[0042] Performance test (I) The epoxy cement composite mortars obtained by using Example 1-18 and Comparative Example 1-4 were tested using the following method. The specific test results are shown in Table 4.

[0043] Compressive strength: The 7d and 28d compressive strength of epoxy cement composite mortar were tested in accordance with GB / T17671.

[0044] Bond strength: The bond strength of epoxy cement composite mortar was tested in accordance with JG / T24-2000.6.14.

[0045] Flexural strength: The flexural strength of epoxy cement composite mortar was tested in accordance with GB / T20487-2013.

[0046] Impact resistance: The impact resistance of epoxy cement composite mortar was tested in accordance with JG / T24-2000.6.12.

[0047] Table 4 Performance test results of different epoxy cement composite mortars The test results in Table 4 show that the 7d and 28d compressive strength, bonding strength and flexural strength of the epoxy cement composite mortar obtained in the present application can reach a maximum of 50.1 MPa, 100.4 MPa, 8.1 MPa and 17.5 MPa, respectively, which improves the strength of the epoxy cement composite mortar and has high impact resistance.

[0048] According to the performance test data of the epoxy cement composite mortar of Application Examples 1-3, it was found that the 7d and 28d compressive strength, bonding strength and flexural strength of the epoxy cement composite mortar obtained in Application Example 2 were 44.2 MPa, 97.1 MPa, 5.6 MPa and 13.5 MPa, respectively, which were all higher than those in Application Example 1 and Application Example 3, indicating that the amount of polyether polyol in the cement-based mortar component of Example 2 is more appropriate, which improves the strength of the epoxy cement composite mortar.

[0049] According to the performance test data of the epoxy cement composite mortar of Application Example 2 and Application Examples 4-5, it was found that the 7d and 28d compressive strength, bonding strength and flexural strength of the epoxy cement composite mortar obtained in Application Example 4 were 45.1 MPa, 97.8 MPa, 5.9 MPa and 14.1 MPa, respectively, which were all higher than those in Application Example 2 and Application Example 5, indicating that the dosage of poly (ethylene glycol) methyl ether methacrylic acid in the cement-based mortar component of Example 4 is more appropriate, which improves the strength of the epoxy cement composite mortar.

[0050] According to the performance test data of the epoxy cement composite mortar of Application Example 4 and Application Examples 6-7, it was found that the 7d and 28d compressive strength, bonding strength and flexural strength of the epoxy cement composite mortar obtained in Application Example 6 were 46.3 MPa, 98.3 MPa, 6.2 MPa and 14.8 MPa, respectively, which were all higher than those of Application Example 4 and Application Example 7, indicating that the dosage of cellulose acetate butyrate in the cement-based mortar component of Example 6 is more appropriate, which improves the strength of the epoxy cement composite mortar.

[0051] According to the performance test data of the epoxy cement composite mortar of Application Examples 8-12, it was found that the 7d and 28d compressive strength, bonding strength and flexural strength of the epoxy cement composite mortar obtained in Application Examples 9-11 were 47.9-48.5MPa, 98.6-99.0MPa, 6.7-7.0MPa and 15.8-16.2MPa, respectively, which were all higher than those of Application Examples 8 and 12, indicating that the weight ratio of nanocellulose to slag powder is 1:(14-18), which is more appropriate and can improve the strength of the epoxy cement composite mortar.

[0052] According to the performance test data of the epoxy cement composite mortar of Application Examples 13-18, it was found that the 7d and 28d compressive strength, bonding strength and flexural strength of the epoxy cement composite mortar obtained in Application Examples 15-17 were 49.5-50.1MPa, 99.8-100.4MPa, 7.8-8.1MPa and 17.2-17.5MPa, respectively, which were all higher than those of Application Examples 13-14 and Application Example 18, indicating that silica aerogel particles were added at the same time as alkylphenol polyoxyethylene ether during the modification of slag micropowder, and the mass ratio of silica aerogel particles to alkylphenol polyoxyethylene ether was 1:(5-10), which was more appropriate, thereby improving the strength of the epoxy cement composite mortar.

[0053] According to the performance test data of the epoxy cement composite mortar of Application Example 1 and Application Comparative Examples 1-4, it was found that the polyether polyols, poly(ethylene glycol) methyl ether methacrylic acid, cellulose acetate butyrate added to the cement mortar components and zinc acetylacetonate added to the water-based epoxy-amine system cross-linked polymer can all improve the strength of the epoxy cement composite mortar to varying degrees.

[0054] Performance Testing (II) The flow properties of the epoxy cement composite mortars obtained in Application Example 2, Application Example 4, Application Example 6, Application Example 10, Application Example 16 and Comparative Examples 1-4 were tested, and the specific test results are shown in Table 5.

[0055] Table 5 Performance test results of different epoxy cement composite mortars The test results in Table 5 show that the epoxy cement composite mortar obtained in this application has a flowability of 145-150 mm in 5 minutes and a flowability of 138-140 mm in 30 minutes, has good fluidity and leveling properties, and can achieve self-leveling construction.

[0056] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. An epoxy cement composite mortar, characterized in that: It includes a cement-based mortar component and a water-based epoxy-amine system cross-linking polymer; the mass ratio of the cement-based mortar component to the water-based epoxy-amine system cross-linking polymer is 1: (3-5); The cement mortar components include the following raw materials in parts by weight: 20-50 parts of Portland cement, 25-40 parts of medium sand with a fineness modulus of 2.6, 40-60 parts of filler, 5-10 parts of polyether polyol, 1-1.2 parts of poly(ethylene glycol) methyl ether methacrylic acid, 0.5-1 part of defoamer, and 0.5-1 part of cellulose acetate butyrate; The waterborne epoxy-amine system cross-linked polymer comprises the following raw materials in parts by weight: 90-100 parts of waterborne epoxy resin, 30-50 parts of polyamide curing agent, 5-15 parts of propylene glycol methyl ether, and 0.1-0.5 parts of zinc acetylacetonate.

2. The epoxy cement composite mortar according to claim 1, characterized in that The raw materials of the cement mortar components also include 0.5-1.5 parts by weight of nanocellulose and 10-20 parts by weight of slag powder.

3. The epoxy cement composite mortar according to claim 2, characterized in that: The weight ratio of the nanocellulose to the slag powder is 1:(14-18).

4. The epoxy cement composite mortar according to claim 3, characterized in that: The slag powder is prepared by nano-polytetrafluoroethylene coating modification, specifically: Add nano-polytetrafluoroethylene to water at a solid content of 40-60%, add alkylphenol polyoxyethylene ether at a concentration of 1-3% of the total mass of the nano-polytetrafluoroethylene, and perform ultrasonic dispersion to obtain a nano-polytetrafluoroethylene dispersion; The nano-polytetrafluoroethylene dispersion is atomized and sprayed onto the surface of slag micropowder with a moisture content of less than 1% at a spray rate of 0.5-1.5 L / min and a spray pressure of 0.2-0.5 MPa. The powder is dried and agglomerates are removed by vibration to obtain modified slag micropowder.

5. The epoxy cement composite mortar according to claim 4, characterized in that: Silicon dioxide aerogel particles are added together with the alkylphenol polyoxyethylene ether.

6. The epoxy cement composite mortar according to claim 5, characterized in that: The mass ratio of the silica aerogel particles to the alkylphenol polyoxyethylene ether is 1:(5-10).

7. The epoxy cement composite mortar according to claim 1, characterized in that: The filler may be at least one of quartz powder, talc powder and calcium carbonate.

8. A method for preparing the epoxy cement composite mortar according to any one of claims 1 to 7, characterized in that: The following steps are involved: The water-based epoxy resin and the polyamide curing agent are uniformly mixed, and propylene glycol methyl ether and zinc acetylacetonate are added to obtain a water-based epoxy-amine system cross-linked polymer; The cement-based mortar components are evenly mixed according to proportion, and a water-based epoxy-amine system cross-linked polymer is added and stirred to obtain an epoxy cement composite mortar.

9. Use of the epoxy cement composite mortar according to any one of claims 1 to 7.

Images