Self-repairing polymer cement-based waterproof material and preparation method thereof
Patent Information
- Application Number
- CN202611208850.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-08-11
- Publication Date
- 2026-09-15
Smart Images
Figure SMS_2
Abstract
Description
Technical Field
[0001] This invention relates to the field of building materials technology, specifically to a self-healing polymer cement-based waterproof material and its preparation method. Background Technology
[0002] Polymer cement mortar is a common method for improving cement mortar materials, combining cement, aggregates, water-soluble organic polymers, and water in a specific ratio. It is available in single-polymer and mixtures of multiple single polymers. The polymer typically forms a film under normal conditions, encapsulating the cement-based material and creating a strong bond between the cement matrix and fine aggregates. Polymer cement mortar is suitable for waterproofing damp areas such as kitchens, bathrooms, balconies, basements, roofs, and exterior walls; seepage prevention in large-scale water conservancy / underground projects such as swimming pools, water towers, reservoirs, tunnels, and subways; repair of cracks and potholes in concrete pavements, bridges, and tunnels; repair of honeycomb and pitted surfaces in building beams and columns; renovation of old building walls; and surface damage repair of highways and airport runways.
[0003] Existing polymer-modified cement mortars typically use acrylic latex, styrene-butadiene latex, and epoxy resin emulsions as organic polymer components. These organic polymers have only weak physical interactions with cement mortar, resulting in low bonding strength and poor waterproofing, making them unsuitable for applications requiring high waterproofing. Furthermore, current research indicates that adding organic polymers to cement mortar can negatively impact its mechanical properties and service life. As the amount of organic polymer added increases, the compressive and flexural strengths of the cement mortar decrease to varying degrees.
[0004] To address the shortcomings of existing technologies, this invention provides a polymer cement mortar material that integrates self-healing, high waterproofing, and high mechanical properties. Summary of the Invention
[0005] In view of the above-mentioned problems of the prior art, the present invention aims to provide a self-healing polymer cement-based waterproof material and its preparation method. The self-healing polymer cement-based waterproof material prepared by the method has excellent self-healing, waterproof and mechanical properties, so as to effectively solve or at least alleviate one or more problems existing in the prior art.
[0006] This invention provides the following technical solution: A self-healing polymer cement-based waterproofing material, comprising, by weight parts: 380-400 parts cement; 60-70 parts fly ash; 15-30 parts mineral powder; 1200-1300 portions of river sand; 0.2 to 1 part of modified graphene; 1-2 parts of complexing agent; 5-20 parts of silicone emulsion; 180-200 servings of tap water.
[0007] A method for preparing a self-healing polymer cement-based waterproof material includes the following preparation steps: (1) Modified graphene was prepared by reacting carboxylated graphene oxide with polyethyleneimine and gallic acid in sequence; (2) Diphenylmethane diisocyanate and γ-aminopropyltriethoxysilane were reacted to prepare hexaethoxysilane; (3) Mix and emulsify hexaethoxysilane and n-octyltriethoxysilane to prepare an organosilicon emulsion; (4) Mix 380-400 parts of cement, 60-70 parts of fly ash, 15-30 parts of mineral powder, 1200-1300 parts of river sand, 0.2-1 parts of modified graphene, and 1-2 parts of complexing agent, stir for 30-60 seconds, add 5-20 parts of organosilicon emulsion and 180-200 parts of tap water, stir for 3-5 minutes, and obtain a self-healing polymer cement-based waterproof material.
[0008] Preferably, the preparation process of the modified graphene in step (1) is as follows: carboxylated graphene oxide and deionized water are mixed at a mass ratio of 1:(800~1000), ultrasonically dispersed for 20~30 min, N-hydroxysuccinimide with a mass of 4~5 times that of carboxylated graphene oxide is added, and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride with a mass of 5~6 times that of carboxylated graphene oxide is added. The mixture is stirred at room temperature for 10~20 min to obtain a carboxylated graphene oxide reaction solution. Polyethyleneimine solution is added dropwise to the carboxylated graphene oxide reaction solution at a uniform rate within 30 min. After the addition is completed, the mixture is stirred at room temperature for 1~2 h. Gallic acid solution is added, and the mixture is stirred for another 3~5 h. The mixture is filtered, washed 3~5 times with anhydrous ethanol, and vacuum dried at 40~50℃ for 15~18 h to obtain modified graphene.
[0009] Preferably, the preparation process of the polyethyleneimine solution is as follows: polyethyleneimine of 2 to 2.6 times the mass of carboxylated graphene oxide and deionized water are mixed at a mass ratio of 1:(90 to 100) to obtain a polyethyleneimine solution.
[0010] Preferably, the preparation process of the gallic acid solution is as follows: gallic acid of 3 to 3.4 times the mass of carboxylated graphene oxide and 50% (v / v) ethanol aqueous solution are mixed at a mass ratio of 1:(50 to 60) to obtain the gallic acid solution.
[0011] Preferably, the molecular weight of the polyethyleneimine is 1000-5000.
[0012] Preferably, the carboxylated graphene oxide can be commercially available or made in-house.
[0013] Preferably, the preparation process of hexaethoxysilane in step (2) is as follows: diphenylmethane diisocyanate and tetrahydrofuran are mixed at a mass ratio of 1:(8~10), and γ-aminopropyltriethoxysilane, which is twice the molar amount of diphenylmethane diisocyanate, is added dropwise at a uniform rate over 30 min at 0°C. After the addition is completed, the temperature is raised to 55~60°C and the mixture is stirred for 3~4 h. Tetrahydrofuran is removed by rotary evaporation under reduced pressure to obtain hexaethoxysilane.
[0014] Preferably, the preparation process of the organosilicon emulsion in step (3) is as follows: by mass fraction, 10-12 parts of hexaethoxysilane, 16-20 parts of n-octyltriethoxysilane, and 3-10 parts of composite emulsifier are mixed, and 65-70 parts of deionized water are added dropwise for stirring and emulsification. The emulsification temperature is set to 60°C, the stirring rate is 800-1200 r / min, the emulsification time is 30-70 min, and the mixture is cooled to room temperature. Then, 1-1.5 parts of silicone-acrylic emulsion are added and mixed evenly to obtain the organosilicon emulsion.
[0015] Preferably, the composite emulsifier is a mixture of Span 80 and Tween 80 to obtain a composite emulsifier with ILB=9~11.
[0016] Preferably, the complexing agent in step (4) is one or a mixture of sodium gluconate, sodium maleate, and sodium citrate.
[0017] Preferably, the cement in step (4) is ordinary Portland cement; The fly ash is Grade I fly ash, with a specific gravity of 2.2 and a median particle size of 15.4 μm; The mineral powder is of type S95; The river sand is ordinary natural river sand with a fineness modulus of 2.37.
[0018] The present invention has the following technical advantages and beneficial effects: This invention utilizes an amidation reaction to sequentially graft polyethyleneimine and gallic acid onto graphene oxide, yielding modified graphene. Numerous studies have shown that adding graphene oxide to cement-based materials can improve their mechanical and durability properties. However, due to calcium ion coordination and complexation, graphene oxide readily aggregates in high-calcium, high-alkalinity cement hydration media. By sequentially grafting polyethyleneimine and gallic acid onto graphene oxide, the dispersibility and stability of graphene oxide in cement-based materials can be improved. Furthermore, gallic acid, a catechol derivative, possesses a catechol structure with strong adhesion and binding capabilities, allowing it to construct interpenetrating networks similar to reinforced concrete with other components, enhancing cohesion and improving the mechanical properties of cement-based materials. Considering the limited carboxyl content on graphene oxide, this invention selects carboxylated graphene oxide for the reaction.
[0019] This invention further involves reacting diphenylmethane diisocyanate and γ-aminopropyltriethoxysilane to prepare hexaethoxysilane; then mixing and emulsifying it with n-octyltriethoxysilane to obtain an organosilicon emulsion; as cement hydration proceeds, water is gradually consumed, and the organosilicon emulsion undergoes demulsification and hydrolysis, thereby combining with the silanol groups on the surface of the cement-based material, i.e., "coupling bridging". Hexaethoxysilane provides a large number of Si-OH bonds, while n-octyltriethoxysilane provides Si-OH and hydrophobic long chains; silane molecules with long hydrophobic tails are chemically anchored to the surface of the cement-based material, forming a hydrophobic network polysilane molecular film on the pore walls of the cement mortar, reducing surface tension and improving the waterproofing ability of the cement-based material.
[0020] The present invention further includes a complexing agent added to the cement-based material, which can complex the Ca in the cement matrix. 2 + Driven by concentration gradient, Ca 2+ Transported from within the cement matrix to the cracks, and reacting with CO3 2- and SiO3 2 - Plasma bonding generates repair products, thereby healing cracks and giving cement-based materials self-healing capabilities. Detailed Implementation
[0021] To enable those skilled in the art to further understand the present invention, specific embodiments of the present invention are described in detail below. However, it should be understood that the embodiments of the present invention described herein are merely exemplary, and the present invention is not limited to these embodiments.
[0022] Raw material information: Carboxylated graphene oxide was prepared in-house. The preparation process was as follows: graphene oxide and deionized water were mixed at a mass ratio of 1:800 and ultrasonically dispersed for 1 hour to obtain a graphene dispersion. Sodium hydroxide with a mass of 10 times that of graphene oxide was added to the graphene dispersion, and ultrasonication was continued for 30 minutes. Bromoacetic acid with a mass of 20 times that of graphene oxide was added, and the mixture was stirred at room temperature for 5 hours. The mixture was then filtered, washed three times with 2 mol / L dilute hydrochloric acid and deionized water, and vacuum dried at 50°C for 16 hours to obtain carboxylated graphene oxide. Polyethyleneimine has a molecular weight of 3500 and is produced by Taian Yingshun Chemical Co., Ltd. Silicone-acrylic emulsion with 50% effective ingredient content, produced by Shandong Shengjing New Material Technology Co., Ltd. Span 80's chemical name is sorbitan monooleate. Tween 80's chemical name is polysorbate-80; The cement is ordinary Portland cement (PO42.5R), produced by Hubei Yadong Cement Co., Ltd. The fly ash is Grade I fly ash, with a specific gravity of 2.2 and a median particle size of 15.4 μm, produced by Qingdao Luqing Industrial Group Co., Ltd. The mineral powder is type S95 and is produced by Wuhan Wuxin New Building Materials Co., Ltd. The river sand is ordinary natural river sand with a fineness modulus of 2.37.
[0023] Example 1: This example provides a method for preparing a self-healing polymer cement-based waterproof material: (1) Carboxylated graphene oxide and deionized water were mixed at a mass ratio of 1:800 and ultrasonically dispersed for 20 min. Four times the mass of N-hydroxysuccinimide and five times the mass of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride were added, and the mixture was stirred at room temperature for 10 min to obtain a carboxylated graphene oxide reaction solution. Two times the mass of polyethyleneimine and deionized water were mixed at a mass ratio of 1:90. The reaction mixture was prepared by mixing gallic acid (3 times the mass of carboxylated graphene oxide) and 50% (v / v) ethanol aqueous solution at a mass ratio of 1:50 to obtain gallic acid solution. The polyethyleneimine solution was added dropwise to the carboxylated graphene oxide reaction solution at a uniform rate over 30 min. After the addition was complete, the mixture was stirred at room temperature for 1 h. The gallic acid solution was then added, and the mixture was stirred for another 3 h. The mixture was then filtered, washed three times with anhydrous ethanol, and dried under vacuum at 40 °C for 18 h to obtain modified graphene. (2) Mix diphenylmethane diisocyanate and tetrahydrofuran at a mass ratio of 1:8. Add γ-aminopropyltriethoxysilane at a uniform rate of 2 times the molar amount of diphenylmethane diisocyanate over 30 min at 0 °C. After the addition is complete, heat to 55 °C and stir for 4 h. Remove tetrahydrofuran by rotary evaporation under reduced pressure to obtain hexaethoxysilane. (3) Mix Span 80 and Tween 80 to obtain a composite emulsifier with ILB=10.5; mix 10 parts hexaethoxysilane, 16 parts n-octyltriethoxysilane and 7 parts composite emulsifier by mass, add 65 parts deionized water dropwise and stir to emulsify, set the emulsification temperature to 60℃, the stirring rate to 1000r / min, the emulsification time to 50min, cool to room temperature, add 1 part silicone-acrylic emulsion, mix evenly to obtain organosilicon emulsion; (4) By mass, mix 380 parts cement, 60 parts fly ash, 15 parts mineral powder, 1200 parts river sand, 0.6 parts modified graphene, and 1.5 parts sodium gluconate, stir for 30 seconds, add 15 parts silicone emulsion and 180 parts tap water, stir for 3 minutes, and obtain self-healing polymer cement-based waterproof material.
[0024] Example 2: This example provides a method for preparing a self-healing polymer cement-based waterproof material: (1) Carboxylated graphene oxide and deionized water were mixed at a mass ratio of 1:900 and ultrasonically dispersed for 25 min. 4.5 times the mass of N-hydroxysuccinimide and 5.5 times the mass of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride were added, and the mixture was stirred at room temperature for 15 min to obtain the carboxylated graphene oxide reaction solution. 2.3 times the mass of polyethyleneimine and deionized water were mixed at a mass ratio of 1:95. Mix to obtain a polyethyleneimine solution; mix gallic acid (3.2 times the mass of carboxylated graphene oxide) and 50% (v / v) ethanol aqueous solution at a mass ratio of 1:55 to prepare a gallic acid solution; add the polyethyleneimine solution dropwise to the carboxylated graphene oxide reaction solution at a uniform rate over 30 min; after the addition is complete, stir the reaction at room temperature for 1.5 h; add the gallic acid solution; continue stirring the reaction for 4 h; filter; wash 4 times with anhydrous ethanol; and vacuum dry at 45 °C for 17 h to obtain modified graphene; (2) Mix diphenylmethane diisocyanate and tetrahydrofuran at a mass ratio of 1:9. Add γ-aminopropyltriethoxysilane at a uniform rate of 2 times the molar amount of diphenylmethane diisocyanate over 30 min at 0 °C. After the addition is complete, heat to 58 °C and stir for 3.5 h. Remove tetrahydrofuran by rotary evaporation under reduced pressure to obtain hexaethoxysilane. (3) Mix Span 80 and Tween 80 to obtain a composite emulsifier with ILB=10.5; mix 11 parts hexaethoxysilane, 18 parts n-octyltriethoxysilane and 7 parts composite emulsifier by mass, add 68 parts deionized water dropwise and stir to emulsify, set the emulsification temperature to 60℃, the stirring rate to 1000r / min, the emulsification time to 50min, cool to room temperature, add 1.3 parts silicone-acrylic emulsion, mix evenly to obtain organosilicon emulsion; (4) By mass, mix 390 parts of cement, 65 parts of fly ash, 25 parts of mineral powder, 1250 parts of river sand, 0.6 parts of modified graphene, and 1.5 parts of sodium maleate, stir for 40 seconds, add 15 parts of silicone emulsion and 190 parts of tap water, stir for 4 minutes, and obtain a self-healing polymer cement-based waterproof material.
[0025] Example 3: This example provides a method for preparing a self-healing polymer cement-based waterproof material: (1) Carboxylated graphene oxide and deionized water were mixed at a mass ratio of 1:1000, ultrasonically dispersed for 30 min, and N-hydroxysuccinimide (5 times the mass of carboxylated graphene oxide) and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (6 times the mass of carboxylated graphene oxide) were added. The mixture was stirred at room temperature for 20 min to obtain a carboxylated graphene oxide reaction solution. Polyethyleneimine (2.6 times the mass of carboxylated graphene oxide) and deionized water were mixed at a mass ratio of 1:100. Mix to obtain a polyethyleneimine solution; mix gallic acid (3.4 times the mass of carboxylated graphene oxide) and 50% (v / v) ethanol aqueous solution at a mass ratio of 1:60 to prepare a gallic acid solution; add the polyethyleneimine solution dropwise to the carboxylated graphene oxide reaction solution at a uniform rate over 30 min; after the addition is complete, stir the reaction at room temperature for 2 h; add the gallic acid solution; continue stirring the reaction for 5 h; filter; wash 5 times with anhydrous ethanol; and vacuum dry at 50 °C for 15 h to obtain modified graphene; (2) Mix diphenylmethane diisocyanate and tetrahydrofuran at a mass ratio of 1:10. Add γ-aminopropyltriethoxysilane at a uniform rate of 2 times the molar amount of diphenylmethane diisocyanate over 30 min at 0 °C. After the addition is complete, heat to 60 °C and stir for 3 h. Remove tetrahydrofuran by rotary evaporation under reduced pressure to obtain hexaethoxysilane. (3) Mix Span 80 and Tween 80 to obtain a composite emulsifier with ILB=10.5; mix 12 parts hexaethoxysilane, 20 parts n-octyltriethoxysilane and 7 parts composite emulsifier by mass, add 70 parts deionized water dropwise and stir to emulsify, set the emulsification temperature to 60℃, the stirring rate to 1000r / min, the emulsification time to 50min, cool to room temperature, add 1.5 parts silicone-acrylic emulsion, mix evenly to obtain organosilicon emulsion; (4) By mass, mix 400 parts cement, 70 parts fly ash, 30 parts mineral powder, 1300 parts river sand, 0.6 parts modified graphene, and 1.5 parts sodium citrate, stir for 60 seconds, add 15 parts silicone emulsion and 200 parts tap water, stir for 5 minutes, and obtain self-healing polymer cement-based waterproof material.
[0026] Comparative Example 1 The difference between Comparative Example 1 and Example 2 is that the phrase “obtain a composite emulsifier with ILB=10.5” in step (3) is changed to “obtain a composite emulsifier with ILB=9”.
[0027] Comparative Example 2 The difference between Comparative Example 2 and Example 2 is that the phrase “obtaining a composite emulsifier with ILB=10.5” in step (3) is changed to “obtaining a composite emulsifier with ILB=9.5”.
[0028] Comparative Example 3 The difference between Comparative Example 3 and Example 2 is that the phrase “obtain a composite emulsifier with ILB=10.5” in step (3) is changed to “obtain a composite emulsifier with ILB=10”.
[0029] Comparative Example 4 The difference between Comparative Example 4 and Example 2 is that the phrase “obtain a composite emulsifier with ILB=10.5” in step (3) is changed to “obtain a composite emulsifier with ILB=11”.
[0030] Comparative Example 5 The difference between Comparative Example 5 and Example 2 is that the "7 parts of composite emulsifier mixture" in step (3) is changed to "3 parts of composite emulsifier mixture".
[0031] Comparative Example 6 The difference between Comparative Example 6 and Example 2 is that the "7 parts of composite emulsifier mixture" in step (3) is changed to "4 parts of composite emulsifier mixture".
[0032] Comparative Example 7 The difference between Comparative Example 7 and Example 2 is that the "7 parts of composite emulsifier mixture" in step (3) is changed to "5 parts of composite emulsifier mixture".
[0033] Comparative Example 8 The difference between Comparative Example 8 and Example 2 is that the "7 parts of composite emulsifier mixture" in step (3) is changed to "6 parts of composite emulsifier mixture".
[0034] Comparative Example 9 The difference between Comparative Example 5 and Example 2 is that the "7 parts of composite emulsifier mixture" in step (3) is changed to "8 parts of composite emulsifier mixture".
[0035] Comparative Example 10 The difference between Comparative Example 10 and Example 2 is that the "7 parts of composite emulsifier mixture" in step (3) is changed to "9 parts of composite emulsifier mixture".
[0036] Comparative Example 11 The difference between Comparative Example 11 and Example 2 is that the "7 parts of composite emulsifier mixture" in step (3) is changed to "10 parts of composite emulsifier mixture".
[0037] Comparative Example 12 The difference between Comparative Example 12 and Example 2 is that the "stirring rate is 1000 r / min" in step (3) is changed to "stirring rate is 800 r / min".
[0038] Comparative Example 13 The difference between Comparative Example 13 and Example 2 is that the "stirring rate is 1000 r / min" in step (3) is changed to "stirring rate is 900 r / min".
[0039] Comparative Example 14 The difference between Comparative Example 14 and Example 2 is that the "stirring rate is 1000 r / min" in step (3) is changed to "stirring rate is 1100 r / min".
[0040] Comparative Example 15 The difference between Comparative Example 15 and Example 2 is that the "stirring rate is 1000 r / min" in step (3) is changed to "stirring rate is 1200 r / min".
[0041] Comparative Example 16 The difference between Comparative Example 16 and Example 2 is that the "emulsification time is 50 min" in step (3) is changed to "emulsification time is 30 min".
[0042] Comparative Example 17 The difference between Comparative Example 17 and Example 2 is that the "emulsification time is 50 min" in step (3) is changed to "emulsification time is 40 min".
[0043] Comparative Example 18 The difference between Comparative Example 18 and Example 2 is that the "emulsification time is 50 min" in step (3) is changed to "emulsification time is 60 min".
[0044] Comparative Example 19 The difference between Comparative Example 19 and Example 2 is that the "emulsification time is 50 min" in step (3) is changed to "emulsification time is 70 min".
[0045] Comparative Example 20 The difference between Comparative Example 20 and Example 2 is that the step (4) of “adding 10 parts of silicone emulsion” is changed to “adding 0 parts of silicone emulsion”.
[0046] Comparative Example 21 The difference between Comparative Example 21 and Example 2 is that the step (4) of "adding 10 parts of silicone emulsion" is changed to "adding 5 parts of silicone emulsion".
[0047] Comparative Example 22 The difference between Comparative Example 22 and Example 2 is that the phrase “add 10 parts silicone emulsion” in step (4) is changed to “add 10 parts silicone emulsion”.
[0048] Comparative Example 23 The difference between Comparative Example 23 and Example 2 is that the step (4) of "adding 10 parts of silicone emulsion" is changed to "adding 20 parts of silicone emulsion".
[0049] Comparative Example 24 The difference between Comparative Example 24 and Example 2 is that “0.6 parts modified graphene” in step (4) is changed to “0 parts modified graphene”.
[0050] Comparative Example 25 The difference between Comparative Example 25 and Example 2 is that “0.6 parts modified graphene” in step (4) is changed to “0.2 parts modified graphene”.
[0051] Comparative Example 26 The difference between Comparative Example 26 and Example 2 is that “0.6 parts modified graphene” in step (4) is changed to “0.4 parts modified graphene”.
[0052] Comparative Example 27 The difference between Comparative Example 27 and Example 2 is that “0.6 parts modified graphene” in step (4) is changed to “0.8 parts modified graphene”.
[0053] Comparative Example 28 The difference between Comparative Example 28 and Example 2 is that “0.6 parts modified graphene” in step (4) is changed to “1 part modified graphene”.
[0054] Comparative Example 29 The difference between Comparative Example 29 and Example 2 is that step (1) is omitted; and the “0.6 parts modified graphene” in step (4) is changed to “0.6 parts graphene oxide”.
[0055] Comparative Example 30 The difference between Comparative Example 30 and Example 2 is in step (4), in which the complexing agent "sodium maleate" is not added.
[0056] Test example: Test Example 1: The effect of the ILB value of the composite emulsifier on the particle size of the silicone emulsion: Test samples: Example 2 and Comparative Examples 1-4; Test method: The particle size of the silicone emulsion was measured using a dynamic light scattering nanoparticle size analyzer. To avoid multiple scattering, the sample was diluted 40 times with deionized water, placed in a standard cuvette, and tested using a green light source with a wavelength of 532 nm. The results are shown in Table 1.
[0057] Table 1 Example 2 ILB=10.5 283nm Comparative Example 1 ILB=9 327nm Comparative Example 2 ILB=9.5 314nm Comparative Example 3 ILB=10 296nm Comparative Example 4 ILB=11 305nm in conclusion: As shown in Table 1, the experimental data indicates that the emulsion with ILB = 10.5 has the smallest particle size. The presumed reason is that when the HLB value is too small, the composite emulsifier is too lipophilic and lacks sufficient hydrophilicity, failing to form a stable oil-in-water emulsion. When the HLB value is too large, the composite emulsifier is too hydrophilic, reducing its ability to encapsulate silicone and hindering compatibility with silicone, resulting in an unstable emulsion. Conversely, when the emulsion has a uniform particle size distribution and small droplet size, the intermolecular attraction is weak, minimizing aggregation and sedimentation, and exhibiting higher kinetic stability. Therefore, this application preferably uses ILB = 10.5.
[0058] Test Example 2: Effects of composite emulsifier dosage, stirring rate, and emulsification time on the properties of silicone emulsions; Test samples: Example 2 and Comparative Examples 5-19; Test method: 1. Emulsion Particle Size: The particle size of the silicone emulsion was measured using a dynamic light scattering nanoparticle size analyzer. To avoid multiple scattering, the sample was diluted 40 times with deionized water, placed in a standard cuvette, and tested using a green light source with a wavelength of 532 nm.
[0059] 2. Emulsion mechanical stability: The stability of the emulsion is classified using centrifugal sedimentation. Level 1: Stratification at 1500 r / min × 20 min; Secondary: Stratification at 2000 r / min × 20 min; Level 3: Stratification at 2500 r / min × 20 min; Level 4: Stratification at 3000 r / min × 20 min; Level 5: Stratification at 3500 r / min × 30 min; Level 6: No stratification at 3500 r / min × 30 min.
[0060] 3. Emulsion stability under static conditions: The silicone emulsion was placed in a transparent bottle, and its layering was observed over a period of three months.
[0061] The test results are shown in Table 2.
[0062] Table 2 Example 2 7 copies 1000r / min 50min 283nm Level 6 Three months without stratification Comparative Example 5 3 copies 1000r / min 50min 467nm Level 2 One month stratification Comparative Example 6 4 copies 1000r / min 50min 431nm Level 4 Two-month stratification Comparative Example 7 5 copies 1000r / min 50min 410nm Level 4 Two-month stratification Comparative Example 8 6 copies 1000r / min 50min 392nm Level 5 Three months without stratification Comparative Example 9 8 copies 1000r / min 50min 277nm Level 6 Three months without stratification Comparative Example 10 9 copies 1000r / min 50min 269nm Level 6 Three months without stratification Comparative Example 11 10 copies 1000r / min 50min 273nm Level 6 Three months without stratification Comparative Example 12 7 copies 800r / min 50min 406nm Level 3 One month stratification Comparative Example 13 7 copies 900r / min 50min 334nm Level 5 Three-month stratification Comparative Example 14 7 copies 1100r / min 50min 276nm Level 6 Three months without stratification Comparative Example 15 7 copies 1200r / min 50min 288nm Level 5 Three-month stratification Comparative Example 16 7 copies 1000r / min 30min 332nm Level 3 One month stratification Comparative Example 17 7 copies 1000r / min 40min 315nm Level 5 Two-month stratification Comparative Example 18 7 copies 1000r / min 60min 294nm Level 6 Three months without stratification Comparative Example 19 7 copies 1000r / min 70min 291nm Level 6 Three-month stratification in conclusion: First, as the amount of composite emulsifier increases, the particle size of the emulsion gradually decreases. However, when the amount of composite emulsifier reaches 7 parts or more, the effect of the amount of composite emulsifier on the particle size of the emulsion is significantly reduced. Excessive emulsifier concentration may change the rheological properties of the emulsion, resulting in increased emulsion viscosity and poor dispersibility, which will affect the quality of the emulsion and cause waste of resources. Therefore, this application prefers a composite emulsifier amount of 7 parts.
[0063] Secondly, as the stirring rate increases, the particle size of the prepared silicone emulsion also becomes smaller. When the stirring rate reaches 1000 r / min, further increasing the stirring rate will not significantly change the particle size of the emulsion. When the stirring rate is too high, the probability of collision between emulsion particles also increases, and the emulsion will generate too much foam, affecting the quality of the emulsion. Therefore, the preferred stirring rate in this application is 1000 r / min.
[0064] Third, when the emulsification time increased from 30 min to 50 min, the emulsion particle size decreased from 332 nm to 283 nm, indicating that the emulsion particle size decreased with the extension of emulsification time. However, excessively long emulsification time not only increases the time cost of emulsification, but also makes it easier for particles to collide and aggregate due to prolonged mechanical stirring, thereby increasing the emulsion particle size and deteriorating the emulsion properties. Therefore, this application preferably uses an emulsification time of 50 min.
[0065] Test Example 3: The effect of silicone emulsion dosage on the waterproofing performance of self-healing polymer cement-based waterproofing materials.
[0066] Test method: Test samples: The self-healing polymer cement-based waterproof materials prepared in Examples 1-3 and Comparative Examples 20-23 were cured for 28 days at a temperature of 20°C and a humidity of 95%.
[0067] 1. Contact angle: The static water contact angle of the sample surface was measured using a standard contact angle measuring instrument.
[0068] 2. Capillary Absorption Test: Referring to the American standard ASTM C1585-13, the samples were placed in an oven and dried at 40°C for 48 hours. The sides of each sample were sealed with epoxy resin to ensure one-dimensional water transfer. The initial mass M0 of each sealed sample was measured (kg). Then, the molded surface of the sample was immersed in water to a depth of 3 mm. After 3 days, the sample was weighed and recorded as M (kg). The capillary water absorption per unit area W was calculated. In the formula, S is the surface area of the test surface (m²). 2 .
[0069] ; The test results are recorded in Table 3.
[0070] Table 3 Example 1 15 copies 109.7° <![CDATA[3.854kg / m 2 ]]> Example 2 15 copies 113.5° <![CDATA[3.763kg / m 2 ]]> Example 3 15 copies 112.8° <![CDATA[3.801kg / m 2 ]]> Comparative Example 20 0 copies 58.1° <![CDATA[5.893kg / m 2 ]]> Comparative Example 21 5 copies 72.4° <![CDATA[5.167kg / m 2 ]]> Comparative Example 22 10 copies 88.9° <![CDATA[4.534kg / m 2 ]]> Comparative Example 23 20 copies 118.3° <![CDATA[3.526kg / m 2 ]]> in conclusion: As shown in Table 3, adding silicone emulsion to self-healing polymer cement-based waterproofing materials can significantly improve their waterproofing ability. Furthermore, the waterproofing ability increases with the amount of silicone emulsion added. However, considering that excessive addition of silicone emulsion can affect the mechanical properties of cement materials, the amount of silicone emulsion used should not be too large.
[0071] Test Example 4: The effect of graphene modification and dosage on the mechanical properties of self-healing polymer cement-based waterproof materials: Test samples: Examples 1-3 and Comparative Examples 24-29; Test method: The flexural and compressive strengths of the samples were measured at 3 days and 28 days according to GB / T 17671-1999. The results are shown in Table 4.
[0072] Table 4 in conclusion: As shown in Table 4, the experimental data indicates that adding modified graphene to the self-healing polymer cement-based waterproof material can improve the flexural strength and compressive strength of the material. When the amount of modified graphene added reaches 0.6 parts, further increasing the amount of modified graphene does not significantly improve the flexural strength and compressive strength, and may even lead to a decrease. This may be because excessive addition of modified graphene can easily cause agglomeration.
[0073] Comparative Example 29 did not undergo surface modification of graphene oxide. Compared with Example 2, it had poorer dispersibility and stability, and its ability to adhere and bond with other components decreased, resulting in poorer mechanical properties than Example 2.
[0074] Test Example 5: Self-Healing Ability Test Test samples: Examples 1-3 and Comparative Example 30; Test method: Precast crack mortar was prepared using the splitting method. Cracks of 0.1-0.5 mm were selected and marked. The crack width at the marked location was measured using a crack width measuring instrument (PTS-E40, Botest, China). The specimens were then placed in a curing room with the scraped surface facing upwards. The specimens were removed after 7, 14, and 28 days of curing, and the moisture in the cracks was dried with a fan. The crack width at the marked location was then measured and recorded. The results are shown in Table 5.
[0075] Table 5 Example 1 Sodium gluconate 0.30mm 0.24mm 0.13mm Crack Closure Example 2 Sodium maleate 0.30mm 0.22mm 0.09mm Crack Closure Example 3 Sodium citrate 0.30mm 0.16mm 0.05mm Crack Closure Comparative Example 30 none 0.30mm 0.28mm 0.27mm 0.27mm in conclusion: Examples 1-3 all added a complexing agent to the self-healing polymer cement-based waterproof material, which can repair cracks, while Comparative Example 30 did not add a complexing agent and had weak repair ability.
[0076] In terms of repair rate, sodium citrate > sodium maleate > sodium gluconate; all of them can close the crack after 28 days.
[0077] The terms "comprising" and "including" as used in this invention include both cases where the invention consists only of the included elements and cases where it includes other elements in addition to the included elements.
[0078] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. The scope of the present invention is broadly defined within the scope of the technical solutions of this application. Any technical entity or method implemented by others that is completely identical to or an equivalent modification of the technical solutions defined in the scope of the present application shall be considered to be covered within the scope of the technical solutions of this application.
Claims
1. A self-healing polymer cement-based waterproof material, characterized in that, By weight, including: 380-400 parts cement; 60-70 parts fly ash; 15-30 parts mineral powder; 1200-1300 portions of river sand; 0.2 to 1 part of modified graphene; 1-2 parts of complexing agent; 5-20 parts of silicone emulsion; 180-200 servings of tap water.
2. A method for preparing a self-healing polymer cement-based waterproof material, characterized in that, The preparation steps include the following: (1) Modified graphene was prepared by reacting carboxylated graphene oxide with polyethyleneimine and gallic acid in sequence; (2) Diphenylmethane diisocyanate and γ-aminopropyltriethoxysilane were reacted to prepare hexaethoxysilane; (3) Mix and emulsify hexaethoxysilane and n-octyltriethoxysilane to prepare an organosilicon emulsion; (4) Mix 380-400 parts of cement, 60-70 parts of fly ash, 15-30 parts of mineral powder, 1200-1300 parts of river sand, 0.2-1 parts of modified graphene, and 1-2 parts of complexing agent, stir for 30-60 seconds, add 5-20 parts of organosilicon emulsion and 180-200 parts of tap water, stir for 3-5 minutes, and obtain a self-healing polymer cement-based waterproof material.
3. The preparation method of the self-healing polymer cement-based waterproof material as described in claim 2, characterized in that, The preparation process of the modified graphene in step (1) is as follows: Carboxylated graphene oxide and deionized water are mixed at a mass ratio of 1:(800~1000), ultrasonically dispersed for 20~30 min, N-hydroxysuccinimide with a mass of 4~5 times that of carboxylated graphene oxide is added, and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride with a mass of 5~6 times that of carboxylated graphene oxide is added. The mixture is stirred at room temperature for 10~20 min to obtain a carboxylated graphene oxide reaction solution. Polyethyleneimine solution is added dropwise to the carboxylated graphene oxide reaction solution at a uniform rate within 30 min. After the addition is completed, the mixture is stirred at room temperature for 1~2 h. Gallic acid solution is added, and the mixture is stirred for another 3~5 h. The mixture is filtered, washed 3~5 times with anhydrous ethanol, and vacuum dried at 40~50℃ for 15~18 h to obtain modified graphene.
4. The preparation method of the self-healing polymer cement-based waterproof material as described in claim 3, characterized in that, The preparation process of the polyethyleneimine solution is as follows: polyethyleneimine of 2 to 2.6 times the mass of carboxylated graphene oxide and deionized water are mixed at a mass ratio of 1:(90 to 100) to obtain a polyethyleneimine solution; The preparation process of the gallic acid solution is as follows: gallic acid of 3 to 3.4 times the mass of carboxylated graphene oxide and 50% (v / v) ethanol aqueous solution are mixed at a mass ratio of 1:(50 to 60) to obtain the gallic acid solution.
5. The preparation method of the self-healing polymer cement-based waterproof material as described in claim 4, characterized in that, The molecular weight of the polyethyleneimine is 1000~5000.
6. The preparation method of the self-healing polymer cement-based waterproof material as described in claim 2, characterized in that, The preparation process of hexaethoxysilane in step (2) is as follows: diphenylmethane diisocyanate and tetrahydrofuran are mixed at a mass ratio of 1:(8~10). At 0℃, γ-aminopropyltriethoxysilane, twice the molar amount of diphenylmethane diisocyanate, is added dropwise at a uniform rate over 30 min. After the addition is complete, the temperature is raised to 55~60℃ and the mixture is stirred for 3~4 h. Tetrahydrofuran is removed by rotary evaporation under reduced pressure to obtain hexaethoxysilane.
7. The preparation method of the self-healing polymer cement-based waterproof material as described in claim 2, characterized in that, The preparation process of the organosilicon emulsion in step (3) is as follows: by mass, 10-12 parts of hexaethoxysilane, 16-20 parts of n-octyltriethoxysilane, and 3-10 parts of composite emulsifier are mixed, and 65-70 parts of deionized water are added dropwise for stirring and emulsification. The emulsification temperature is set at 60°C, the stirring rate is 800-1200 r / min, the emulsification time is 30-70 min, and the mixture is cooled to room temperature. Then, 1-1.5 parts of silicone-acrylic emulsion are added and mixed evenly to obtain the organosilicon emulsion.
8. The preparation method of the self-healing polymer cement-based waterproof material as described in claim 7, characterized in that, The composite emulsifier is obtained by mixing Span 80 and Tween 80 to obtain a composite emulsifier with ILB=9~11.
9. The preparation method of the self-healing polymer cement-based waterproof material as described in claim 2, characterized in that, The complexing agent in step (4) is one or a mixture of sodium gluconate, sodium maleate, and sodium citrate.
10. The preparation method of the self-healing polymer cement-based waterproof material as described in claim 2, characterized in that, The cement mentioned in step (4) is ordinary Portland cement; The fly ash is Grade I fly ash, with a specific gravity of 2.2 and a median particle size of 15.4 μm; The mineral powder is of type S95; The river sand is ordinary natural river sand with a fineness modulus of 2.37.