Silane-modified cement-based polymers, methods of making, and use in waterproofing coatings
Patent Information
- Application Number
- CN202611030001.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-10
- Publication Date
- 2026-10-20
AI Technical Summary
然而，现有硅烷改性聚合物（如硅烷封端聚醚）虽具优异的柔韧性和耐候性，但缺乏动态修复能力，一旦产生微裂纹，性能将不可逆地衰减
本发明的硅烷封端聚醚在固化过程中，硅烷端基水解生成硅醇(-Si-OH)，随后与水泥水化产物中的羟基发生缩合反应，在材料表面形成低表面能的疏水层，赋予了材料表面优异的疏水性能；
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Abstract
Description
Technical Field
[0001] This invention relates to the field of waterproof coating preparation technology, specifically to a silane-modified cement-based polymer, its preparation method, and its application in waterproof coatings. Background Technology
[0002] The degradation of the durability of concrete structures is essentially due to moisture and harmful ions (Cl). - SO4 2- (etc.) Through microcracks and pore penetration, a chain reaction is triggered. Traditional protective measures (such as densification design and mineral admixtures) can delay initial deterioration, but cannot cope with dynamic damage to existing structures. In particular, when microcracks appear in the waterproof coating, moisture penetration accelerates freeze-thaw damage to the substrate, steel corrosion, and chemical erosion. Traditional repairs (such as surface sealing or grouting) can only temporarily seal the damage and cannot eradicate the internal diffusion pathways.
[0003] Silane coupling agents form a Si-O-Si network through hydrolysis and condensation, which can construct a hydrophobic layer on the concrete surface, reducing water absorption by more than 90%. Their active functional groups (such as amino and epoxy groups) can also bond with the hydroxyl groups of the substrate, enhancing interfacial adhesion. However, while existing silane-modified polymers (such as silane-terminated polyethers) possess excellent flexibility and weather resistance, they lack dynamic repair capabilities; once microcracks develop, their performance will irreversibly degrade.
[0004] Therefore, there is an urgent need to develop a silane-modified cement-based polymer that combines self-healing components with silane-modified waterproofing properties to form a "hydrophobic-repair" dual-effect mechanism, enabling the material to maintain stable waterproofing performance during long-term use and solving the problem of performance degradation caused by microcracks in traditional waterproofing materials. Summary of the Invention
[0005] (a) Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a silane-modified cement-based polymer, its preparation method, and its application in waterproof coatings, thereby resolving the problems mentioned in the background section.
[0006] (II) Technical Solution To achieve the above objectives, the present invention provides the following technical solution: a silane-modified cement-based polymer, comprising the following raw materials by mass fraction: 40-60 parts of silicate cement; 20-30 parts of silane-terminated polyether; 5-8 parts of nano-SiO2; 3-8 parts of self-healing component; Sodium citrate 0.05–0.2 parts; 20-30 parts of quartz sand; 10-15 parts talc; 0.3-0.5 parts of polycarboxylate superplasticizer; The self-healing component includes hollow glass fiber, the inner cavity of which is sealed and filled with a reactive composition; And a silica shell covering the outer surface of the hollow glass fiber, the shell having a gradient pore structure that varies radially.
[0007] As a further preferred option, the silane-terminated polyether is one or more of methoxysilane-terminated polyether, ethoxysilane-terminated polyether, and isocyanate silane-terminated polyether.
[0008] As a further preferred option, the self-healing component includes the following raw materials: hollow glass fiber, liquid silane, catalyst, mercaptosilane, and silicon dioxide; Liquid silane, catalyst and mercaptosilane are mixed in a mass ratio of 90-95:2-3:2-8 and then filled into hollow glass fibers, with a filling rate of >90%.
[0009] As a further preferred option, the catalyst is dibutyltin dilaurate or bismuth carboxylate DY-20.
[0010] As a further preferred option, the hollow glass fiber has a diameter of 20-100 μm and a length of 0.5-2 μm.
[0011] As a further preferred embodiment, the SiO2 is deposited on the outer wall of the hollow glass fiber through atomic layer deposition, with a deposition thickness of 100-200 nm.
[0012] As a further preferred embodiment, the SiO2 comprises an outer layer, a middle layer, and an inner layer from the outside to the inside, with a thickness ratio of 3:3:4 and pore sizes of 10-50nm, 2-10nm, and <2nm, respectively.
[0013] A method for preparing a silane-modified cement-based polymer, comprising the following steps: ① Preparation of self-healing components. Hollow glass fibers were cleaned with 0.05 mol / L hydrochloric acid to remove surface impurities and increase hydroxyl density. After cleaning with deionized water and drying, they were ready for use. Weigh out the liquid silane, catalyst and mercaptosilane in proportion, mix them evenly to obtain a mixture; The mixture is vacuum-injected into the hollow glass fiber cavity, with a filling rate of >90%, and then sealed by hot pressing or chemical curing. SiO2 was deposited layer by layer on the surface of the fiber obtained in the previous step by atomic layer deposition to obtain the self-repairing component. ② Mix silicate cement, nano-SiO2, quartz sand and talc powder at 300-500 rpm in proportion to obtain dry mix; ③ Add silane-terminated polyether, sodium citrate and polycarboxylate superplasticizer to the dry mix, stir at 500-1000 rpm for 10-15 min, add self-healing components, stir at 300-500 rpm for 5-10 min until the slurry is homogeneous, and apply an electric field of 1-3 kV / cm during the stirring process to align the glass fibers along the stress direction to obtain silane-modified cement-based polymer.
[0014] The application of a silane-modified cement-based polymer in waterproof coatings includes the following steps: ① Grind the substrate to a roughness of ≤0.5mm and a moisture content of <9%, and apply a primer to enhance adhesion; ② Apply the silane-modified cement-based polymer as described in any one of claims 1-7 by scraping, with a thickness ≤ 6 mm; ③Cure for 72 hours or accelerate curing with 60℃ hot air (surface dry in 2 hours).
[0015] (III) Beneficial Effects This invention provides a silane-modified cement-based polymer, its preparation method, and its application in waterproof coatings, which has the following beneficial effects: During the curing process, the silane-terminated polyether of the present invention undergoes hydrolysis of the silane end groups to generate silanol (-Si-OH), which then undergoes a condensation reaction with the hydroxyl groups in the cement hydration products to form a low surface energy hydrophobic layer on the material surface, thereby endowing the material surface with excellent hydrophobic properties. Furthermore, the self-healing components and waterproofing performance create a synergistic enhancement effect. When microcracks appear in the material, the glass fibers break, releasing liquid silane, which diffuses along the crack surface and forms a new hydrophobic layer under the action of a catalyst. Simultaneously, the mercaptosilane reacts with Ca in the matrix. 2+ By forming coordination bonds, the material anchors the silane, preventing silane migration and enhancing interfacial bonding, thereby restoring or even enhancing the waterproof performance of the area. This dual protection mechanism enables the material to maintain stable waterproof performance during long-term use, solving the problem of performance degradation caused by microcracks in traditional waterproof materials. Finally, the silica coating with gradient pore size deposited on the outer atomic layer of the glass fiber restricts the diffusion of silane molecules. Its high specific surface area and surface hydroxyl groups can adsorb silane, thereby slowing down the release rate of liquid silane. Combined with the multi-level fracture of the fiber, multiple repairs can be achieved. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the preparation process of the silane-modified cement-based polymer of the present invention. Detailed Implementation
[0017] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0018] The following disclosure provides many different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided, but those skilled in the art will recognize the application of other processes and / or the use of other materials.
[0019] This invention provides a silane-modified cement-based polymer, comprising the following raw materials by mass fraction: 40-60 parts of silicate cement; 20-30 parts of silane-terminated polyether; 5-8 parts of nano-SiO2; 3-8 parts of self-healing component; Sodium citrate 0.05–0.2 parts; 20-30 parts of quartz sand; 10-15 parts talc; 0.3 to 0.5 parts of polycarboxylate superplasticizer.
[0020] The silane-terminated polyether is one or more of methoxysilane-terminated polyether, ethoxysilane-terminated polyether, and isocyanate silane-terminated polyether. The terminal siloxane groups of the silane-terminated polyether, such as -Si(OCH3)3, hydrolyze to generate silanol Si-OH, which forms a chemical bond -Si-O-Si- with the hydroxyl groups -OH on the surface of the cement substrate. This forms a low-surface-energy hydrophobic layer on the material surface and significantly improves the interfacial adhesion strength through chemical bonding. Simultaneously, the polyether backbone of the silane-terminated polyether has low surface energy and high permeability, which can wet the microporous structure of the cement substrate and enhance adhesion.
[0021] The self-healing components include the following raw materials: hollow glass fiber, liquid silane, catalyst, mercaptosilane, and silicon dioxide; Liquid silane, catalyst, and mercaptosilane are mixed in a mass ratio of 90-95:2-3:2-8 and then filled into hollow glass fibers, with a filling rate of >90%. Hollow glass fibers with a diameter of 20-100µm and a length of 0.5-2µm are sourced from Huizhou Xindahui Technology Co., Ltd., model XD-GF-UF. Silica is coated on the outer wall of hollow glass fiber, with a coating thickness of 100-200 nanometers; The silica coating consists of an outer layer, a middle layer, and an inner layer, with a thickness ratio of 3:3:4. The pore sizes are macropores (10-50 nm), mesopores (2-10 nm), and micropores (<2 nm), respectively. By controlling the thickness of the silica coating to 100-200 nm and the gradient distribution of pore size, its pore structure restricts the diffusion rate of silane molecules, forming a "slow-release barrier" to limit the diffusion of silane molecules. Its high specific surface area and surface hydroxyl groups can form hydrogen bonds with silane to further adsorb silane, thereby slowing down the release rate of liquid silane. Specifically, the macropores of the outer layer facilitate the rapid diffusion of the product to the crack area for repair, the micropores of the inner layer restrict the release rate of the catalyst, thereby reducing the generation of side reactions, and the middle layer increases the residence time of the reactants and promotes the reaction. Through the staged release of reactants, multiple repairs of cracks are achieved.
[0022] Specifically, the liquid silane is one or more of isobutyltriethoxysilane, methylchlorosilane, and perfluorooctyltriethoxysilane.
[0023] The catalyst is dibutyltin dilaurate or bismuth carboxylate DY-20.
[0024] Understandably, the cracks cause the glass fibers to break, releasing liquid silanes, catalysts, and mercaptosilanes. The liquid silanes hydrolyze into silanols (-Si-OH) under the influence of ambient moisture and the catalyst. These silanols then react with each other or with hydroxyl groups on the substrate surface to form a hydrophobic siloxane network (-Si-O-Si-), sealing the cracks and blocking corrosive media. The specific reaction formula is as follows: Si-OR + H2O → ROH + Si(OH)3; Si(OH)3→-Si-O-Si-+H2O; Si(OH)3 + substrate-OH → substrate-O-Si- + H2O; Simultaneously, during the hydrolysis and condensation of mercaptosilane, its own -SH groups react with Ca in the cement matrix. 2+ Coordination bonds are formed to prevent silane migration and enhance interfacial bonding, ensuring that the bond strength is maintained even after multiple repairs. The specific reaction formula is as follows: (CH3O)3Si-(CH2)3-SH+H2O→(HO)3Si-(CH2)3-SH+CH3OH; (HO)3Si-(CH2)3-SH+Ca 2+ →(HO)2Si-(CH2)3-S-Ca-O-Si(OH)2-R+H + R-(CH2)3-SH+Ca 2+ →R-(CH2)3-S-Ca + +H + In addition, the -SH group undergoes a displacement reaction with liquid silane under the action of a catalyst to form thioether bonds, which participate in the cross-linking of the silicon-oxygen network and further promote crack repair.
[0025] This invention also provides a method for preparing a silane-modified cement-based polymer, comprising the following steps: ① Preparation of self-healing components Hollow glass fibers were cleaned with 0.05 mol / L hydrochloric acid to remove surface impurities and increase hydroxyl density. After cleaning with deionized water and drying, they were ready for use. Weigh out the liquid silane, catalyst and mercaptosilane in proportion, mix them evenly to obtain a mixture; The mixture is vacuum-injected into the hollow glass fiber cavity, with a filling rate of >90%, and then sealed by hot pressing or chemical curing. SiO2 was deposited layer by layer on the surface of the fiber obtained in the previous step by atomic layer deposition, with a total thickness of 100-200 nm and a porosity of 30%-50%. The layer consisted of an outer layer, a middle layer and an inner layer from the outside to the inside, with a thickness ratio of 3:3:4 and pore sizes of 10-50 nm, 2-10 nm and <2 nm, respectively, which were obtained from the repair component. Atomic layer deposition uses tris(dimethylamino)silane with a purity ≥99.999% as a precursor, and ozone (O3) or water vapor (H2O) as the reaction gas. The specific process is as follows: Outer layer: Temperature: 150-200℃, promotes precursor diffusion and pore structure formation; Plasma-assisted: Radio frequency plasma with a power of 50-100W is used to enhance reactivity and induce macropore formation; Pulse duration: 2 seconds for precursor pulse, 5 seconds for O3 exposure, 10 seconds for purge, and approximately 300-400 cycles. Intermediate layer: Temperature: 100-150℃, balancing reaction rate and pore uniformity; Precursor ratio: concentration diluted to 50% to slow down the deposition rate and form mesopores; Pulse duration: 1 second precursor pulse, 3 seconds H2O exposure, 8 seconds purging, approximately 400-500 cycles; Inner layer: Temperature: 80-120℃, low temperature suppresses lattice defects and improves compactness; Plasma off: Only thermal ALD is used to avoid damage to the microporous structure by plasma; Pulse duration: precursor pulse 0.5s, H2O exposure 2s, purging 6s, cycle number approximately 600-700 times.
[0026] ② Mix silicate cement, nano-SiO2, quartz sand and talc powder at 300-500 rpm in proportion to obtain dry mix; ③ Add silane-terminated polyether, sodium citrate and polycarboxylate superplasticizer to the dry mixture, stir at 500-1000 rpm for 10-15 min, add self-healing components, stir at 300-500 rpm for 5-10 min until the slurry is homogeneous, and apply an electric field (1-3 kV / cm) during stirring to align the glass fibers along the stress direction to obtain silane-modified cement-based polymer.
[0027] The application of a silane-modified cement-based polymer in waterproof coatings includes the following steps: Grind the substrate to a roughness of ≤0.5mm and a moisture content of <9%, and apply a primer to enhance adhesion; Apply the above-mentioned silane-modified cement-based polymer by scraping, with a thickness ≤6mm; Curing time is 72 hours or hot air at 60℃ can be used to accelerate curing (surface dry in 2 hours).
[0028] To further understand the present invention, the silane-modified cement-based polymer provided by the present invention will be described below with reference to the embodiments. The scope of protection of the present invention is not limited by the following embodiments.
[0029] Experimental Example 1 Preparation of self-healing components: ① Clean the hollow glass fiber with 0.05mol / L hydrochloric acid, rinse with deionized water until neutral, and dry at 60℃ for later use; ②Weigh isobutyltriethoxysilane, dibutyltin dilaurate and mercaptosilane in a mass ratio of 90:3:7, mix them evenly to obtain a mixed solution; ③ With a vacuum of 10 Pa, the mixture is injected into the hollow glass fiber cavity, with a filling rate of 90%, and then sealed by hot pressing. ④ SiO2 was deposited layer by layer on the surface of the fiber obtained in the previous step by atomic layer deposition. The outer layer was 30 nm thick with a pore size of 35-40 nm and a porosity of 30%-35%; the middle layer was 30 nm thick with a pore size of 5-10 nm and a porosity of 35%-40%; and the inner layer was 40 nm thick with a pore size of <2 nm and a porosity of 30%, thus obtaining the self-repairing component A.
[0030] Experimental Example 2 ① Clean the hollow glass fiber with 0.05mol / L hydrochloric acid, rinse with deionized water until neutral, and dry at 60℃ for later use; ② Weigh out methylchlorosilane, bismuth carboxylate DY-20 and mercaptosilane in a mass ratio of 95:2:3, mix them evenly to obtain a mixed solution; ③ With a vacuum of 10 Pa, the mixture is injected into the hollow glass fiber cavity, with a filling rate of 90%, and then sealed by chemical curing. ④ SiO2 was deposited layer by layer on the surface of the fiber obtained in the previous step by atomic layer deposition. The outer layer was 60 nm thick with a pore size of 35-40 nm and a porosity of 30%-35%; the middle layer was 60 nm thick with a pore size of 5-10 nm and a porosity of 35%-40%; and the inner layer was 80 nm thick with a pore size of <2 nm and a porosity of 30%, thus obtaining the self-repairing component B.
[0031] Experimental Example 3 ① Clean the hollow glass fiber with 0.05mol / L hydrochloric acid, rinse with deionized water until neutral, and dry at 60℃ for later use; ② Weigh out perfluorooctyltriethoxysilane, bismuth carboxylate DY-20 and mercaptosilane in a mass ratio of 90:2:8, mix them evenly to obtain a mixed solution; ③ With a vacuum of 10 Pa, the mixture is injected into the hollow glass fiber cavity, with a filling rate of 90%, and then sealed by chemical curing. ④ SiO2 was deposited layer by layer on the surface of the fiber obtained in the previous step by atomic layer deposition. The outer layer was 30 nm thick with a pore size of 35-40 nm and a porosity of 30%-35%; the middle layer was 30 nm thick with a pore size of 5-10 nm and a porosity of 35%-40%; and the inner layer was 40 nm thick with a pore size of <2 nm and a porosity of 30%, thus obtaining the self-repairing component C.
[0032] Experiment Example 4 ① Weigh out 40 parts of silicate cement, 20 parts of nano-SiO2, 20 parts of quartz sand and 10 parts of talc powder by weight, mix them evenly at 350 rpm to obtain dry mix; ② Add 20 parts of methoxysilane-terminated polyether, 10 parts of ethoxysilane-terminated polyether, 0.05 parts of sodium citrate and 0.3 parts of polycarboxylate superplasticizer to the dry mixture, stir at 800 rpm for 12 min, add self-healing component A, stir at 300 rpm for 10 min until the slurry is homogeneous, and apply an electric field of 1.5 kV / cm during the stirring process to align the glass fibers along the stress direction to obtain silane-modified cement-based polymer A.
[0033] Experimental Example 5 ① Weigh out 60 parts of silicate cement, 30 parts of nano-SiO2, 30 parts of quartz sand and 15 parts of talc powder by weight, mix them evenly at 400 rpm to obtain dry mix; ② Add 10 parts isocyanate silane-terminated polyether, 10 parts ethoxysilane-terminated polyether, 0.2 parts sodium citrate and 0.5 parts polycarboxylate superplasticizer to the dry mixture, stir at 1000 rpm for 10 min, add self-healing component B, stir at 300 rpm for 10 min until the slurry is homogeneous, and apply an electric field of 2 kV / cm during stirring to align the glass fibers along the stress direction to obtain silane-modified cement-based polymer B.
[0034] Experimental Example 6 ① Weigh out 50 parts of silicate cement, 25 parts of nano-SiO2, 25 parts of quartz sand and 12 parts of talc powder by weight, mix them evenly at 400 rpm to obtain dry mix; ② Add 20 parts of methoxysilane-terminated polyether, 0.2 parts of sodium citrate and 0.5 parts of polycarboxylate superplasticizer to the dry mixture, stir at 1000 rpm for 10 min, add self-healing component C, stir at 300 rpm for 10 min until the slurry is homogeneous, and apply an electric field of 3 kV / cm during the stirring process to align the glass fibers along the stress direction to obtain silane-modified cement-based polymer C.
[0035] Comparative Example 1
[0036] Purchase commercially available polymer-modified cement-based waterproof coating, manufactured by Dega (Guangzhou) Building Materials Co., Ltd., model number Dega K11.
[0037] Comparative Example 2
[0038] ① Weigh out 40 parts of silicate cement, 20 parts of nano-SiO2, 20 parts of quartz sand, 10 parts of talc powder, 0.05 parts of sodium citrate, and 0.3 parts of polycarboxylate superplasticizer by weight and mix them evenly at 350 rpm; ② Add self-healing component A to the interior, stir at 300 rpm for 10 min until the slurry is homogeneous, and apply an electric field with an intensity of 1.5 kV / cm during the stirring process to align the glass fibers along the stress direction to obtain comparative cement-based polymer A.
[0039] Comparative Example 3
[0040] ① Clean the hollow glass fiber with 0.05mol / L hydrochloric acid, rinse with deionized water until neutral, and dry at 60℃ for later use; ②Weigh isobutyltriethoxysilane, dibutyltin dilaurate and mercaptosilane in a mass ratio of 90:3:7, mix them evenly to obtain a mixed solution; ③ With a vacuum of 10 Pa, the mixture is injected into the hollow glass fiber cavity with a filling rate of 90%, and then sealed by hot pressing to obtain the self-healing component A.
[0041] Comparative Example 4
[0042] ① Clean the hollow glass fiber with 0.05mol / L hydrochloric acid, rinse with deionized water until neutral, and dry at 60℃ for later use; ②Weigh isobutyltriethoxysilane, dibutyltin dilaurate and mercaptosilane in a mass ratio of 90:3:7, mix them evenly to obtain a mixed solution; ③ With a vacuum of 10 Pa, the mixture is injected into the hollow glass fiber cavity, with a filling rate of 90%, and then sealed by hot pressing. ④ SiO2 was deposited layer by layer on the surface of the fiber obtained in the previous step by atomic layer deposition, with a thickness of 100 nm, a pore size of 35-40 nm, and a porosity of 30%-35%, to obtain the self-healing component B.
[0043] Comparative Example 5
[0044] ① Weigh out 40 parts of silicate cement, 20 parts of nano-SiO2, 20 parts of quartz sand and 10 parts of talc powder by weight, mix them evenly at 350 rpm to obtain dry mix; ② Add 20 parts of methoxysilane-terminated polyether, 10 parts of ethoxysilane-terminated polyether, 0.05 parts of sodium citrate and 0.3 parts of polycarboxylate superplasticizer to the dry mixture, stir at 800 rpm for 12 min, add the comparative self-healing component A, stir at 300 rpm for 10 min until the slurry is homogeneous, and apply an electric field of 1.5 kV / cm during the stirring process to align the glass fibers along the stress direction to obtain the comparative silane modified cement-based polymer A.
[0045] Comparative Example 6
[0046] ① Weigh out 40 parts of silicate cement, 20 parts of nano-SiO2, 20 parts of quartz sand and 10 parts of talc powder by weight, mix them evenly at 350 rpm to obtain dry mix; ② Add 20 parts of methoxysilane-terminated polyether, 10 parts of ethoxysilane-terminated polyether, 0.05 parts of sodium citrate and 0.3 parts of polycarboxylate superplasticizer to the dry mix, stir at 800 rpm for 12 min, add the comparative self-healing component B, stir at 300 rpm for 10 min until the slurry is homogeneous, and apply an electric field of 1.5 kV / cm during the stirring process to align the glass fibers along the stress direction to obtain the comparative silane modified cement-based polymer B.
[0047] Test example: Using a universal testing machine, the tensile strength, elongation at break, and bond strength of the silane-modified cement-based polymers obtained in Experimental Examples 4-6 and the comparative polymers obtained in Comparative Examples 1-2 and 5-6 were determined according to the GB / T 23445 test standard, GB / T 19250 test standard, and GB / T23445 standard. The test results are shown in Table 1.
[0048] According to the GB / T 16777 test standard and the GB 23440 test standard, the impermeability and impermeability grade of the silane modified cement-based polymers obtained in Experimental Examples 4-6 and the comparative polymers obtained in Comparative Examples 1-2 and 5-6 were determined. The test results are shown in Table 1.
[0049] According to the GB / T 30693-2014 test standard, the contact angle of the silane-modified cement-based polymers obtained in Experimental Examples 4-6 and the comparative polymers obtained in Comparative Examples 1-2 and 5-6 was measured. The test results are shown in Table 1.
[0050] Table 1. Statistical Table of Physical Performance Tests for Each Embodiment and Comparative Example
[0051]
[0052] The silane-modified cement-based polymers obtained in Experiments 4-6 and the comparative polymers obtained in Comparative Examples 1-2 and 5-6 were coated with a thickness of 15 mm. After curing for 72 hours, cracks with a length of 5-10 cm, a width of <5 mm, and a depth of <3 mm were scratched on the surface. The impermeability and tensile strength recovery rate after standing for 24 hours were tested in an environment of 25℃ and 50% humidity. The recovered materials were subjected to three cycles of crack repair test. The test results are shown in Table 2.
[0053] Table 2. Statistical table of self-healing performance tests for each embodiment and comparative example.
[0054]
[0055] In summary, in the silane-modified cement-based polymer of the present invention, during the curing process of the silane-terminated polyether, the terminal siloxane groups hydrolyze to generate silanol, which then undergoes a condensation reaction with the hydroxyl groups in the cement hydration products, forming a low surface energy hydrophobic layer on the material surface and significantly improving the interfacial bonding strength through chemical bonding. Moreover, when cracks appear in the material (width < 5 mm), the glass fibers break and release liquid silane, which diffuses along the crack surface and hydrolyzes into silanol -Si-OH under the action of ambient moisture and catalyst. The silanols react with each other or with the hydroxyl groups on the substrate surface to form a hydrophobic siloxane network -Si-O-Si-, sealing the cracks and blocking corrosive media. At the same time, the mercaptosilane reacts with Ca in the matrix. 2+ Coordination bonds are formed, which anchor the silane, preventing silane migration and enhancing interfacial bonding, thereby restoring or even enhancing the waterproof performance of the area. Finally, the silica coating with gradient pore size deposited on the outer atomic layer of the glass fiber restricts the diffusion of silane molecules. Its high specific surface area and surface hydroxyl groups can adsorb silane, thereby slowing down the release rate of liquid silane. Combined with the multi-level fracture of the fiber, multiple repairs can be achieved. Through the self-healing components and multiple protection mechanisms of waterproof performance, the material can maintain stable waterproof performance during long-term use, solving the problem of performance degradation caused by microcracks in traditional waterproof materials.
[0056] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A silane-modified cement-based polymer, characterized by, By weight unit, including the following raw materials: Portland cement 40-60 parts; Silane-terminated polyether 20-30 parts; Nano-SiO2 5-8 parts; Self-repairing component 3-8 parts; Sodium citrate 0.05-0.2 parts; Quartz sand 20-30 parts; Talc powder 10-15 parts; Polycarboxylic acid water reducer 0.3-0.5 parts; The self-repairing component includes hollow glass fiber, the inner cavity of which is sealed and filled with a reactive composition; And a silica shell layer coated on the outer surface of the hollow glass fiber, the shell layer has a radially varying gradient pore structure.
2. The silane-modified cementitious polymer of claim 1, wherein, The silane-terminated polyether is one or more of methoxysilane-terminated polyether, ethoxysilane-terminated polyether, and isocyanate silane-terminated polyether.
3. The silane-modified cementitious polymer of claim 1, wherein, The self-repairing component includes the following raw materials: hollow glass fiber, liquid silane, catalyst, mercapto silane, and silica; The reactive composition includes liquid silane, catalyst, and mercapto silane, mixed in a mass ratio of 90-95:2-3:2-8 and then filled into the hollow glass fiber at a filling rate of >90%.
4. The silane-modified cementitious polymer of claim 3, wherein, The catalyst is dibutyltin dilaurate or bismuth carboxylate DY-20.
5. The silane modified cementitious polymer of claim 3, wherein, The hollow glass fiber has a diameter of 20-100um and a length of 0.5-2um.
6. The silane modified cementitious polymer of claim 3, wherein, The SiO2 is deposited on the outer wall of the hollow glass fiber by atomic layer deposition, with a deposition thickness of 100-200nm.
7. The silane-modified cementitious polymer of claim 6, wherein, The SiO2 includes an outer layer, an intermediate layer, and an inner layer from the outside to the inside, with a thickness ratio of 3:3:4 and pore diameters of 10-50nm, 2-10nm, and <2nm, respectively.
8. A method of preparing a silane-modified cement-based polymer, characterized by, Preparation of the silane-modified cement-based polymer of any one of claims 1-7, including the following steps: ① Preparation of self-repairing component Wash the hollow glass fiber with 0.05mol / L hydrochloric acid to remove surface impurities and increase the density of hydroxyl groups, then wash with deionized water and dry for standby; Take liquid silane, catalyst, and mercapto silane in proportion, mix well, and obtain a mixed solution; Vacuum inject the mixed solution into the inner cavity of the hollow glass fiber at a filling rate of >90%, and seal by heat pressing or chemical curing; Deposited SiO2 on the surface of the fiber obtained in the previous step by atomic layer deposition method to obtain the self-repairing component; ② Mix Portland cement, nano-SiO2, quartz sand, and talc powder in proportion at 300-500rpm to obtain dry mixture; ③ Add silane-terminated polyether, sodium citrate, and polycarboxylic acid water reducer to the dry mixture, stir at 500-1000rpm for 10-15min, add the self-repairing component, stir at 300-500rpm for 5-10min until the slurry is homogeneous, and apply an electric field with a strength of 1-3 kV / cm during stirring to arrange the glass fiber along the stress direction to obtain the silane-modified cement-based polymer.
9. Use of a silane-modified cement-based polymer in a waterproofing coating, characterized in that, Including the following steps: Grind the base surface to a roughness of ≤0.5mm, moisture content <9%, and apply a primer to enhance adhesion; ② Apply the silane-modified cement-based polymer of any one of claims 1-7 by scraping, with a thickness of ≤6mm; ③ Curing for 72 hours or accelerated curing by hot air at 60℃ for 2 hours.