Nano-based anti-freezing and anti-seepage congealed fat as well as preparation method and application thereof

Abstract

The invention relates to the technical field of building materials, in particular to nano-based anti-freezing and anti-seepage congealed fat as well as a preparation method and application thereof. The nano-based anti-freezing and anti-permeability congealed fat is composed of a group A and a group B. The group A is composed of the following raw materials in parts by weight: 40-70 parts of epoxy resin, 10-20 parts of rubber modified epoxy resin, 8-15 parts of multifunctional epoxy resin, 2-7 parts of a dispersing agent and 8-15 parts of filler. The component B is prepared from the following raw materials in parts by weight: 3 to 8 parts of carborundum, 1 to 3 parts of a resistance increasing agent, 1 to 3 parts of a coupling agent, 4 to 8 parts of a toughening agent, 8 to 14 parts of a curing agent, 4 to 8 parts of a nano accelerant and 6 to 10 parts of a functional aid. The prepared nano-based anti-freezing and anti-seepage congealed grease has good anti-seepage and anti-freezing effects when being applied to concrete, meanwhile, the migration rate of chloride ions can be reduced, and the nano-based anti-freezing and anti-seepage congealed grease can be used as a repairing material in a special concrete bridge protective fence.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering materials, and particularly relates to a nano-based anti-freezing and anti-seepage coagulum and its preparation method and application. Background Art

[0002] The bridge anti-collision guardrail is one of the important components of a bridge. Maintaining its integrity is of great significance for ensuring the stability of the bridge structure and the safety of vehicle driving.

[0003] The anti-collision guardrails of bridges built in the early stage generally have design defects. The thickness of their concrete protective layers is mostly less than 3 cm, which can no longer meet the existing code requirements. Especially in areas where deicing salts are used, the code requires that the thickness of the protective layer of the anti-collision guardrail should not be less than 4 cm. With the rapid growth of traffic volume and the continuous increase of vehicle axle loads, before many bridges reach their designed service life, their cement concrete structures have shown varying degrees of deterioration, damage, and decline in service performance, and urgent repairs are needed.

[0004] During the repair construction process, it was found that the thickness of the protective layer of the existing anti-collision guardrails is generally less than 2 cm, and even less than 1 cm in some local areas, which seriously affects the durability of the structure. After analysis, the main reasons for this problem are as follows: First, during the construction process of the original bridge, when pouring concrete, the steel bar cage tilted outwards due to the accumulation of aggregates; second, when the construction personnel adjusted the position of the formwork to ensure the aesthetic appearance of the guardrail line, they failed to synchronously adjust the steel bar positioning. After long-term use, the steel bars in these parts with too thin protective layers expanded due to corrosion, and finally led to damage phenomena such as cracking and peeling of the concrete surface.

[0005] The road surface is continuously scoured and worn by rainwater and water flow, causing damage to the bottom structure. In addition, when there is snow on the road surface in winter, the brine generated by using snow melting agents penetrates into the interior of the cement concrete. The long-term salt corrosion causes the cement mortar to powder, form a white paste when mixed with water and float up, resulting in a decrease in the overall compressive strength of the concrete and surface peeling. For bridge guardrails, snow melting agents are strong corrosives that can penetrate into the interior of bridge cement and corrode the steel bar cage. Due to the continuous downward penetration of the brine, cracks and peeling gradually appear in the concrete at the root of the guardrail, the steel bars are exposed and corroded. This phenomenon is commonly known as "root rot", which not only directly affects the safe operation of the project, but may also cause more serious structural problems, and the subsequent maintenance and reinforcement costs are extremely high.

[0006] Polycarboxylate superplasticizer is the latest generation of high-performance superplasticizer, and there are currently a large number of applications in the field of cement concrete. Based on different cements and different construction requirements, various polycarboxylate superplasticizers with different functions have been developed, such as high-efficiency water-reducing type, slump retention type, early strength type, etc. Developing a polycarboxylate admixture for roller-compacted concrete that integrates multiple functions is still a technical challenge. Summary of the Invention

[0007] In view of the deficiencies existing in the above-mentioned prior art, the present invention provides a nano-based antifreeze and anti-seepage coagulating fat and its preparation method and application.

[0008] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows: A nano-based antifreeze and anti-seepage coagulating fat, which is composed of Group A and Group B. The raw materials of Group A are composed of the following parts by weight: 40-70 parts by weight of epoxy resin, 10-20 parts by weight of rubber-modified epoxy resin, 8-15 parts by weight of polyfunctional epoxy resin, 2-7 parts by weight of dispersant, and 8-15 parts by weight of filler; the raw materials of Group B are composed of the following parts by weight: 3-8 parts by weight of emery, 1-3 parts by weight of anti-increasing agent, 1-3 parts by weight of coupling agent, 4-8 parts by weight of toughening agent, 8-14 parts by weight of curing agent, 4-8 parts by weight of nano-promoter, and 6-10 parts by weight of functional auxiliary agent, and the functional auxiliary agent is a modified nano-silica composite.

[0009] The weight ratio of Group A to Group B is (1.2-2.8):1.

[0010] The polyfunctional epoxy resin is at least one of polyphenol-type glycidyl ether epoxy resin, bisphenol A-type epoxy resin, hydrogenated bisphenol A-type epoxy resin, bisphenol S-type epoxy resin, and stilbene-type epoxy resin.

[0011] The dispersant is any one of sodium dodecylbenzenesulfonate, octylphenol polyoxyethylene ether, and fatty acid monoethanolamide; the filler is any one of silica, calcium carbonate, talcum powder, alumina, and montmorillonite; the anti-increasing agent is at least one of cellulose hydroxypropyl methyl ether and fiber and non-ionic polyacrylamide; the coupling agent is one or any combination of silane coupling agent, titanate coupling agent, and aluminate coupling agent; the toughening agent is one or any combination of polyethylene glycol, polypropylene glycol, polyethylene glycol monomethyl ether, polyethylene glycol dimethyl ether, and tetraethylene glycol monooctyl ether; the curing agent is a fatty polyamine-type curing agent, an isocyanate curing agent, an acid anhydride-type curing agent, or an aromatic amine-type curing agent; the nano-promoter is tetrabutylthiuram disulfide.

[0012] The preparation method of the rubber-modified epoxy resin is as follows: Under a nitrogen atmosphere, 3-6 parts by weight of hydroxyl-terminated liquid nitrile rubber and 0.5-2 parts by weight of 2,4-toluene diisocyanate are mixed and reacted at 75-100 °C for 2-6 h to obtain a prepolymer; 8-16 parts by weight of epoxy resin is added and heated to 90-110 °C, and the reaction is carried out under vacuum insulation for 3-6 h to obtain the rubber-modified epoxy resin.

[0013] Hydroxy nitrile rubber modified epoxy resin. The hydroxy nitrile rubber has a highly polar -CN group, which can be well dispersed in the epoxy resin matrix during the prepolymerization reaction and curing reaction, improving the toughness of the modified epoxy resin.

[0014] Adding nano-silica into the nano-based antifreeze and impermeable grease can effectively eliminate the negative impact of epoxy resin emulsion on cement-based materials. Nano-silica can fill the micropores and fine cracks of the material, effectively improve the microscopic phenomenon of the cement paste, reduce the number of pores, so it can be used as a densifier, promote cement hydration, accelerate the formation of calcium silicate hydrate gel (C-S-H), optimize the pore structure, make up for the strength loss, and improve the freeze-thaw resistance of the material. However, silica itself does not participate in the cross-linking reaction of epoxy resin, has poor dispersibility in the matrix, and cannot be well compatible with the epoxy resin matrix. If nano-silica is directly added, it cannot directly enhance the cross-linking density due to easy agglomeration. Therefore, it needs to be modified.

[0015] After modification, the hydrophobicity of silica is improved, and its compatibility with other components of the epoxy resin matrix is also correspondingly improved. It can effectively prevent the penetration of water molecules, further improve the compact strength of concrete, improve the pore structure, reduce the penetration channels, and then improve the impermeability of concrete.

[0016] Although adding modified nano-silica can effectively solve the impermeability problem, it cannot solve the antifreeze problem at the same time. Especially when used for the reinforcement of bridges in the extremely cold northern regions, snow can penetrate into the bridge cement and corrode its steel skeleton. In the long run, cracks, spalling will appear in the concrete at the root of the guardrail, and the steel bars will be exposed and corroded, which is commonly known as "root rot". Therefore, there is an urgent need to provide a multifunctional additive that can be both impermeable and antifreeze to further expand its application range.

[0017] The present invention polymerizes 2-acryloyloxy-1,3-propanediol, methallyl alcohol polyoxyethylene ether and acrylic acid to provide relatively long side chains and hydrophilic groups for the polycarboxylate superplasticizer; then by introducing graphene oxide that can fill the micropores and capillary pores in concrete, reduce the porosity, lower the permeability, increase the steric hindrance, enhance the dispersibility, and graphene oxide can reduce the free water in concrete, lower the expansion pressure in freeze-thaw cycles, further improve its density, reduce the expansion of microcracks caused by freeze-thaw cycles, enhance the impermeability and antifreeze property, so that the prepared polycarboxylate superplasticizer has a certain anti-shrinkage effect and can play an antifreeze role in areas with large day-night temperature differences.

[0018] The preparation method of the modified nano-silica composite is as follows: S1 Mix nano-silica and an ethanol aqueous solution and ultrasonicate; add a silane coupling agent and ammonia water, heat and stir to obtain silane-modified nano-silica; S2 Mix acrylic acid, 2-acryloyloxy-1,3-propanediol, methallyl alcohol polyoxyethylene ether and water uniformly, add graphene oxide and stir; then add mercaptoacetic acid and ammonium persulfate and heat, and recover the solvent by vacuum distillation to obtain a polycarboxylate superplasticizer containing graphene; S3 Mix the above-mentioned silane-modified nano-silica and water and ultrasonicate, add the above-mentioned polycarboxylate superplasticizer containing graphene and ammonium persulfate and heat, and freeze-dry to obtain a modified nano-silica composite.

[0019] In the preparation of the polycarboxylate superplasticizer of the present invention, graphene oxide is introduced because graphene oxide can increase the yield of calcium silicate hydrate in concrete, promote the formation and arrangement of cement hydration crystals, improve the structure of the cement stone and aggregate interface, reduce the porosity and increase the density. While improving the microstructure, graphene oxide can also improve the compressive strength, tensile strength, impermeability, chloride ion erosion resistance, freeze-thaw resistance and other properties of concrete. It avoids the problem that directly adding a graphene oxide dispersion alone will cause large agglomerates to form after long-term storage. After the agglomerated graphene oxide is incorporated into concrete, its distribution in the concrete is uneven, resulting in a large number of pores locally and causing a decline in the performance of the concrete.

[0020] The modified nano-silica composite prepared by the present invention not only has the impermeability of silica, but also has a polycarboxylate superplasticizer containing graphene with freeze-thaw and impermeability resistance. The inventor effectively combines the two to prepare a multifunctional modified nano-silica composite. After adding a polycarboxylate superplasticizer containing graphene to the concrete system, the number of capillary pores in the concrete can be greatly reduced, forming a highly dense microstructure in the concrete, further reducing the internal defects in the concrete, having good impermeability, high and low temperature resistance, and effectively hindering the migration of chloride ions; the modified nano-silica not only has improved hydrophobicity, but also has improved compatibility with other components of the epoxy resin matrix, can effectively prevent the penetration of water molecules, and at the same time further improves the compactness strength of the concrete, improves the pore structure, thereby reducing the penetration channels, and then greatly improving the freeze-thaw and impermeability resistance of the concrete, thus effectively enhancing the durability of the bridge guardrail.

[0021] Preferably, the preparation method of the modified nano-silica composite is as follows: S1: Take 3 - 6 parts by weight of nano - silica and 40 - 60 parts by weight of 50 - 70wt% ethanol aqueous solution, mix them, and carry out ultrasonic treatment for 20 - 50 min at a temperature of 35 - 50°C, an ultrasonic power of 100 - 300 W, and an ultrasonic frequency of 40 - 70 kHz; add 0.8 - 2 parts by weight of silane coupling agent and 0.5 - 2 parts by weight of ammonia water with a concentration of 20 - 30wt%, stir at 30 - 50°C and 300 - 500 rpm for 4 - 8 h, cool, centrifuge, wash, and dry to obtain silane - modified nano - silica; S2: Mix 2 - 6 parts by weight of acrylic acid, 3 - 7 parts by weight of 2 - hydroxy - 1,3 - propanediol 2 - acrylate, 20 - 40 parts by weight of methallyl alcohol polyoxyethylene ether, and 60 - 120 parts by weight of water evenly, add 0.1 - 0.4 parts by weight of graphene oxide, stir at 20 - 40°C and 300 - 500 rpm for 4 - 8 h; then add 0.3 - 0.8 parts by weight of mercaptoacetic acid and 0.3 - 0.8 parts by weight of ammonium persulfate; keep the temperature at 50 - 70°C and 300 - 500 rpm for 1 - 4 h, and recover the solvent by vacuum distillation to obtain a polycarboxylate water - reducing agent containing graphene; S3: Take 2 - 5 parts by weight of the above - mentioned silane - modified nano - silica and 40 - 100 parts by weight of water, carry out ultrasonic treatment at an ultrasonic power of 100 - 300 W and an ultrasonic frequency of 40 - 70 kHz for 20 - 50 min, add 3 - 7 parts by weight of the above - mentioned polycarboxylate water - reducing agent containing graphene and 0.1 - 0.5 parts by weight of ammonium persulfate, stir at 70 - 85°C and 400 - 800 rpm for 50 - 90 min, and freeze - dry to obtain a modified nano - silica composite.

[0022] The silane coupling agent is at least one of 3 - [bis(2 - hydroxyethyl)amino]propane - triethoxysilane, N - (3 - acryloyloxy - 2 - hydroxypropyl)-3 - aminopropyltriethoxysilane, and N - (6 - aminohexyl)aminomethyltriethoxysilane.

[0023] The preparation method of the nano - based antifreeze and impermeable coagulant includes the following steps: (1) First, weigh each component raw material; (2) Mix epoxy resin, rubber - modified epoxy resin, multi - functional epoxy resin, dispersant, and filler, and stir at 40 - 60°C and 4000 - 1000 rpm for 20 - 50 min to obtain component A; (3) Then, stir carborundum, anti - thickening agent, coupling agent, toughening agent, and functional additive at normal temperature and 1000 - 2000 rpm for 0.5 - 2 h, and finally add curing agent and nano - promoter, and continue to stir for 15 min to obtain component B; (4) Mix component A and component B evenly to obtain the nano - based antifreeze and impermeable coagulant.

[0024] The nano-based antifreeze and anti-seepage gel is used in concrete bridge guardrails, pavements, and construction projects.

[0025] The nano-based antifreeze and anti-seepage gel is used as a repair material in special concrete bridge guardrails, road surfaces, and construction projects.

[0026] Beneficial effects of the invention: The invention provides a nano-based antifreeze and anti-seepage gel and its preparation method and application, adopts specific components in specific contents to achieve overall good interaction. The product has antifreeze and anti-seepage properties and resistance to chloride ion migration. It has good crack resistance when used in concrete and is particularly suitable for bridge reinforcement.

[0027] The present invention can significantly reduce the number of capillaries in concrete by adding functional additives to the nano-based antifreeze and anti-seepage gel, so that the concrete forms a highly dense microstructure, further reduces internal defects in the concrete, improves the compact strength of the concrete, improves the pore structure, has good anti-seepage performance, and effectively hinders the migration of chloride ions, thereby greatly improving the antifreeze and anti-seepage performance of the concrete, thereby effectively improving the durability of bridge guardrails under complex environmental conditions such as high cold and humidity, extending the service life of hydraulic concrete structures under freeze-thaw alternating environments, and reducing later maintenance costs, achieving multiple goals at one stroke, and being suitable for popularization and use. DETAILED DESCRIPTION

[0028] The above content of the present invention is further described in detail below in conjunction with specific implementation modes, but this should not be understood as the scope of the above subject matter of the present invention being limited to the following embodiments.

[0029] Introduction of some raw materials in this application: Epoxy resin was purchased from Hubei Zhenzhengfeng New Materials Co., Ltd. with the brand name MF-4101H.

[0030] Hydrogenated bisphenol A epoxy resin was purchased from Green Union (Jining) Chemical Technology Co., Ltd., model 5001.

[0031] Cellulose hydroxypropyl methyl ether was purchased from Cellulose hydroxypropyl methyl ether, viscosity: 250,000 Pa·s.

[0032] Octylphenol polyoxyethylene ether was purchased from Shanghai Zhenlishi Network Technology Co., Ltd., model DOWFAX X-405.

[0033] Polyethylene glycol dimethyl ether was purchased from Anhui Nanmu Chemical Co., Ltd., model SF-260 / 400.

[0034] The hydroxyl-terminated liquid nitrile rubber was purchased from Jining Tangyi Chemical Co., Ltd., model SH-820.

[0035] Methyl allyl alcohol polyoxyethylene ether was purchased from Liaoning Shengxin Technology Co., Ltd., model SX-702.

[0036] The nano-silica was purchased from Xingxin New Material Technology Co., Ltd., Qinghe County, with a particle size / mesh number of 15,000 meshes.

[0037] The graphene oxide was purchased from Hebei Ruihuang Metal Materials Co., Ltd., with a particle size / mesh number of 35,000 meshes.

[0038] Example 1

[0039] A nano-based antifreeze and impermeable grease is composed of Group A and Group B. The weight ratio of Group A to Group B is 2:1. Group A consists of the following raw materials in parts by weight: 50 parts by weight of epoxy resin, 15 parts by weight of rubber-modified epoxy resin, 10 parts by weight of multi-functional epoxy resin, 5 parts by weight of dispersant, and 10 parts by weight of silica; Group B consists of the following raw materials in parts by weight: 4 parts by weight of emery, 2 parts by weight of anti-increment agent, 2 parts by weight of coupling agent, 6 parts by weight of toughening agent, 10 parts by weight of curing agent, 6 parts by weight of nano-promoter, and 8 parts by weight of functional additive.

[0040] The nano-promoter is tetrabutylthiuram disulfide.

[0041] The multi-functional epoxy resin is hydrogenated bisphenol A type epoxy resin.

[0042] The anti-increment agent is hydroxypropyl methyl cellulose.

[0043] The dispersant is octylphenol polyoxyethylene ether.

[0044] The coupling agent is silane coupling agent KH-550.

[0045] The toughening agent is polyethylene glycol dimethyl ether.

[0046] The curing agent is tetraethylenepentamine.

[0047] The preparation method of the rubber-modified epoxy resin is as follows: Under a nitrogen atmosphere, 4 parts by weight of hydroxyl-terminated liquid nitrile rubber and 1 part by weight of 2,4-toluene diisocyanate are mixed and reacted at 90 °C for 4 h to obtain a prepolymer; 12 parts by weight of epoxy resin is added and heated to 100 °C, and vacuum is pumped to keep the reaction for 4 h to obtain the rubber-modified epoxy resin.

[0048] The functional additive is nano-silica.

[0049] The preparation method of the nano-based antifreeze and impermeable grease is as follows: (1) First, weigh each component of the raw materials; (2) Mix the epoxy resin, rubber-modified epoxy resin, multi-functional epoxy resin, dispersant, and silica, and stir at 50 °C and 6000 rpm for 30 min to obtain Component A; (3) Next, mix carborundum, anti-plasticizer, coupling agent, toughening agent, and functional additive at room temperature with stirring at 1200 rpm for 1 h. Finally, add the curing agent and nano-promoter and continue stirring for 15 min to obtain Component B. (4) Mix Component A and Component B evenly with stirring to obtain the nano-based anti-freezing and anti-seepage coagulating grease.

[0050] Example 2

[0051] A nano-based anti-freezing and anti-seepage coagulating grease is composed of Component A and Component B. The weight ratio of Component A to Component B is 2:1. Component A consists of the following raw materials in parts by weight: 50 parts by weight of epoxy resin, 15 parts by weight of rubber-modified epoxy resin, 10 parts by weight of polyfunctional epoxy resin, 5 parts by weight of dispersant, and 10 parts by weight of silica; Component B consists of the following raw materials in parts by weight: 4 parts by weight of carborundum, 2 parts by weight of anti-plasticizer, 2 parts by weight of coupling agent, 6 parts by weight of toughening agent, 10 parts by weight of curing agent, 6 parts by weight of nano-promoter, and 8 parts by weight of functional additive.

[0052] The nano-promoter is tetrabutylthiuram disulfide.

[0053] The polyfunctional epoxy resin is hydrogenated bisphenol A type epoxy resin.

[0054] The anti-plasticizer is hydroxypropyl methylcellulose.

[0055] The dispersant is octylphenol polyoxyethylene ether.

[0056] The coupling agent is silane coupling agent KH-550.

[0057] The toughening agent is polyethylene glycol dimethyl ether.

[0058] The curing agent is tetraethylenepentamine.

[0059] The preparation method of the rubber-modified epoxy resin is as follows: Under a nitrogen atmosphere, mix 4 parts by weight of hydroxyl-terminated liquid nitrile rubber with 1 part by weight of 2,4-toluene diisocyanate, place it at 90 °C and react for 4 h to obtain a prepolymer; add 12 parts by weight of epoxy resin, heat to 100 °C, and react under vacuum insulation for 4 h to obtain the rubber-modified epoxy resin.

[0060] The functional additive is modified nano-silica. The preparation method of the modified nano-silica is as follows: Take 4 parts by weight of nano-silica and 50 parts by weight of 60 wt% ethanol aqueous solution, mix them, and ultrasonicate at a temperature of 40 °C, an ultrasonic power of 200 W, and an ultrasonic frequency of 60 kHz for 30 min; add 1.2 parts by weight of silane coupling agent and 1 part by weight of 25 wt% ammonia water, stir at 40 °C and 400 rpm for 6 h, cool, centrifuge, wash, and dry to obtain the modified nano-silica.

[0061] The silane coupling agent is 3-[bis(2-hydroxyethyl)amino]propane-triethoxysilane.

[0062] The preparation method of the nano-based antifreeze and impermeable coagulant grease is as follows: (1) First, weigh each component raw material; (2) Mix epoxy resin, rubber-modified epoxy resin, polyfunctional epoxy resin, dispersant, and silica, and stir at 50°C and 6000 rpm for 30 min to obtain Component A; (3) Then, stir carborundum, anti-blocking agent, coupling agent, toughening agent, and functional additive at room temperature and 1200 rpm for 1 h, and finally add a curing agent and a nano promoter, and continue to stir for 15 min to obtain Component B; (4) Mix Component A and Component B and stir evenly to obtain the nano-based antifreeze and impermeable coagulant grease.

[0063] Example 3

[0064] A nano-based antifreeze and impermeable coagulant grease is composed of Component A and Component B. The weight ratio of Component A to Component B is 2:1. Component A is composed of the following raw materials in parts by weight: 50 parts by weight of epoxy resin, 15 parts by weight of rubber-modified epoxy resin, 10 parts by weight of polyfunctional epoxy resin, 5 parts by weight of dispersant, and 10 parts by weight of silica; Component B is composed of the following raw materials in parts by weight: 4 parts by weight of carborundum, 2 parts by weight of anti-blocking agent, 2 parts by weight of coupling agent, 6 parts by weight of toughening agent, 10 parts by weight of curing agent, 6 parts by weight of nano promoter, and 8 parts by weight of functional additive.

[0065] The nano promoter is tetrabutylthiuram disulfide.

[0066] The polyfunctional epoxy resin is hydrogenated bisphenol A epoxy resin.

[0067] The anti-blocking agent is cellulose hydroxypropyl methyl ether.

[0068] The dispersant is octylphenol polyoxyethylene ether.

[0069] The coupling agent is silane coupling agent KH-550.

[0070] The toughening agent is polyethylene glycol dimethyl ether.

[0071] The curing agent is tetraethylenepentamine.

[0072] The preparation method of the rubber-modified epoxy resin is as follows: Under a nitrogen atmosphere, mix 4 parts by weight of hydroxyl-terminated liquid nitrile rubber with 1 part by weight of 2,4-toluene diisocyanate, place it at 90°C and react for 4 h to obtain a prepolymer; add 12 parts by weight of epoxy resin and heat to 100°C, evacuate and keep warm for 4 h to obtain the rubber-modified epoxy resin.

[0073] The functional additive is a modified nano-silica composite, and the preparation method of the modified nano-silica composite is as follows: S1 Mix 4 parts by weight of acrylic acid, 5 parts by weight of 2-hydroxy-1,3-propanediol diacrylate, 30 parts by weight of methallyl alcohol polyoxyethylene ether and 80 parts by weight of water evenly, add 0.2 parts by weight of graphene oxide, and stir at 30 °C and 400 rpm for 6 h; then add 0.5 parts by weight of mercaptoacetic acid and 0.5 parts by weight of ammonium persulfate; keep warm at 60 °C and 400 rpm for 2 h, and recover the solvent by reduced pressure distillation to obtain a polycarboxylate water reducer containing graphene; S2 Take 3 parts by weight of nano-silica and 60 parts by weight of water, mix them, ultrasonicate at an ultrasonic power of 200 W and an ultrasonic frequency of 60 kHz for 30 min, add 5 parts by weight of the above polycarboxylate water reducer containing graphene and 0.2 parts by weight of ammonium persulfate, stir at 75 °C and 600 rpm for 60 min, and freeze-dry to obtain a modified nano-silica composite.

[0074] The preparation method of the nano-based anti-freezing and anti-seepage coagulating grease is as follows: (1) First, weigh each component raw material; (2) Mix epoxy resin, rubber-modified epoxy resin, multi-functional epoxy resin, dispersant, and silica, and stir at 50 °C and 6000 rpm for 30 min to obtain component A; (3) Then, mix emery, anti-blocking agent, coupling agent, toughening agent, and functional additive, stir at room temperature and 1200 rpm for 1 h, and finally add a curing agent and a nano-promoter, and continue to stir for 15 min to obtain component B; (4) Mix component A and component B evenly to obtain the nano-based anti-freezing and anti-seepage coagulating grease.

[0075] Example 4

[0076] A nano-based anti-freezing and anti-seepage coagulating grease is composed of component A and component B, and the weight ratio of component A to component B is 2:1. Component A is composed of the following raw materials in parts by weight: 50 parts by weight of epoxy resin, 15 parts by weight of rubber-modified epoxy resin, 10 parts by weight of multi-functional epoxy resin, 5 parts by weight of dispersant, and 10 parts by weight of silica; Component B is composed of the following raw materials in parts by weight: 4 parts by weight of emery, 2 parts by weight of anti-blocking agent, 2 parts by weight of coupling agent, 6 parts by weight of toughening agent, 10 parts by weight of curing agent, 6 parts by weight of nano-promoter, and 8 parts by weight of functional additive.

[0077] The nano-promoter is tetrabutylthiuram disulfide.

[0078] The multi-functional epoxy resin is hydrogenated bisphenol A type epoxy resin.

[0079] The anti - thickening agent is hydroxypropyl methylcellulose.

[0080] The dispersant is octylphenol polyoxyethylene ether.

[0081] The coupling agent is silane coupling agent KH - 550.

[0082] The toughening agent is polyethylene glycol dimethyl ether.

[0083] The curing agent is tetraethylenepentamine.

[0084] The preparation method of the rubber - modified epoxy resin is as follows: Under a nitrogen atmosphere, 4 parts by weight of hydroxyl - terminated liquid nitrile rubber and 1 part by weight of 2,4 - toluene diisocyanate are mixed and reacted at 90 °C for 4 h to obtain a prepolymer; 12 parts by weight of epoxy resin is added and heated to 100 °C, and vacuum - insulated and reacted for 4 h to obtain the rubber - modified epoxy resin.

[0085] The functional auxiliary agent is a modified nano - silica composite, and the preparation method of the modified nano - silica composite is as follows: S1: Take 4 parts by weight of nano - silica and 50 parts by weight of 60 wt% ethanol aqueous solution, mix them, and ultrasonicate for 30 min at a temperature of 40 °C, an ultrasonic power of 200 W, and an ultrasonic frequency of 60 kHz; add 1.2 parts by weight of silane coupling agent and 1 part by weight of 25 wt% ammonia water, stir at 40 °C and 400 rpm for 6 h, cool, centrifuge, wash, and dry to obtain silane - modified nano - silica; S2: Mix 4 parts by weight of acrylic acid, 5 parts by weight of 2 - hydroxy - 1,3 - propanediol diacrylate, 30 parts by weight of methallyl alcohol polyoxyethylene ether, and 80 parts by weight of water evenly, add 0.2 parts by weight of graphene oxide, and stir at 30 °C and 400 rpm for 6 h; then add 0.5 parts by weight of mercaptoacetic acid and 0.5 parts by weight of ammonium persulfate; keep warm at 60 °C and 400 rpm for 2 h, and recover the solvent by vacuum distillation to obtain a polycarboxylate water - reducing agent containing graphene; S3: Take 3 parts by weight of the above - mentioned silane - modified nano - silica and 60 parts by weight of water, ultrasonicate at an ultrasonic power of 200 W and an ultrasonic frequency of 60 kHz for 30 min, add 5 parts by weight of the above - mentioned polycarboxylate water - reducing agent containing graphene and 0.2 parts by weight of ammonium persulfate, stir at 75 °C and 600 rpm for 60 min, and freeze - dry to obtain the modified nano - silica composite.

[0086] The silane coupling agent is 3 - [bis(2 - hydroxyethyl)amino] propane - triethoxysilane.

[0087] The preparation method of the nano - based antifreeze and impermeable coagulant is as follows: (1) First, weigh each component raw material; (2) Mix epoxy resin, rubber-modified epoxy resin, multi-functional epoxy resin, dispersant, and silica, and stir at 50°C and 6000 rpm for 30 min to obtain Component A; (3) Then mix emery, anti-plasticizer, coupling agent, toughening agent, and functional additive, stir at room temperature and 1200 rpm for 1 h, and finally add curing agent and nano-promoter, and continue to stir for 15 min to obtain Component B; (4) Mix Component A and Component B evenly to obtain nano-based anti-freezing and anti-seepage coagulant.

[0088] Example 5

[0089] It is basically the same as Example 4, and the difference is that: The functional additive is a modified nano-silica composite, and the preparation method of the modified nano-silica composite is as follows: S1: Take 4 parts by weight of nano-silica and 50 parts by weight of 60 wt% ethanol aqueous solution, mix them, and ultrasonicate at a temperature of 40°C, an ultrasonic power of 200 W, and an ultrasonic frequency of 60 kHz for 30 min; add 1.2 parts by weight of silane coupling agent and 1 part by weight of 25 wt% ammonia water, stir at 40°C and 400 rpm for 6 h, cool, centrifuge, wash, and dry to obtain silane-modified nano-silica; S2: Mix 4 parts by weight of acrylic acid, 5 parts by weight of 2-hydroxy-1,3-propanediyl diacrylate, 30 parts by weight of methallyl alcohol polyoxyethylene ether, and 80 parts by weight of water evenly, and stir at 30°C and 400 rpm for 6 h; then add 0.5 parts by weight of mercaptoacetic acid and 0.5 parts by weight of ammonium persulfate; keep warm at 60°C and 400 rpm for 2 h, and recover the solvent by vacuum distillation to obtain polycarboxylate water reducer; S3: Take 3 parts by weight of the above silane-modified nano-silica and 60 parts by weight of water, mix them, ultrasonicate at an ultrasonic power of 200 W and an ultrasonic frequency of 60 kHz for 30 min, add 5 parts by weight of the above polycarboxylate water reducer containing graphene and 0.2 parts by weight of ammonium persulfate, stir at 75°C and 600 rpm for 60 min, and freeze-dry to obtain the modified nano-silica composite.

[0090] The silane coupling agent is 3-[bis(2-hydroxyethyl)amino]propane-triethoxysilane.

[0091] Example 6

[0092] It is basically the same as Example 4, and the difference is that rubber-modified epoxy resin is not added: Component A is composed of the following raw materials in parts by weight: 65 parts by weight of epoxy resin, 10 parts by weight of multi-functional epoxy resin, and 5 parts by weight of dispersant.

[0093] Test Example 1

[0094] Freeze-thaw and impermeability test: Referring to the test method of the national standard GB / T 50082-2024 "Standard for Test Methods of Long-term Performance and Durability of Concrete", the nano-based freeze-thaw and impermeability coagulant prepared in the above Examples 1-6 was added to the concrete. The formula of the concrete is: 50 parts by weight of cement, 18 parts by weight of fly ash, 100 parts by weight of sand, 160 parts by weight of kaolin, 30 parts by weight of water, and 15 parts by weight of the nano-based freeze-thaw and impermeability coagulant prepared in the above Examples 1-6. The concrete added with the nano-based freeze-thaw and impermeability coagulant prepared in Examples 1-6 was subjected to freeze-thaw and impermeability tests. Each group was tested 5 times and the average value was taken. The results are shown in Table 1.

[0095] Table 1 Test results of freeze-thaw and impermeability performance Freezing resistance Impermeability pressure (MPa) Example 1 F375 3.1 Example 2 F400 3.6 Example 3 F425 4.3 Example 4 F450 5.7 Example 5 F440 5.1 Example 6 F445 5.4 Test Example 2 Chloride ion migration coefficient test: The chloride ion migration coefficient of the concrete added with the nano-based freeze-thaw and impermeability coagulant prepared in Examples 1-6 was tested. The test was carried out referring to the test method of the national standard GB / T 50082-2024 "Standard for Test Methods of Long-term Performance and Durability of Concrete". Each group was tested 5 times and the average value was taken. The results are shown in Table 2.

[0096] Table 2 Test results of chloride ion migration coefficient <![CDATA[Chloride ion migration coefficient D RCM (×10 -12 m 2 / s)]]> Example 1 11.5 Example 2 9.6 Example 3 7.3 Example 4 2.1 Example 5 3.2 Example 6 2.4 From the above results, it can be seen that the nano-based freeze-thaw and impermeability coagulant prepared by the present invention has good impermeability and freeze-thaw resistance effects when applied to concrete, and at the same time can reduce the chloride ion migration rate. Comparing Examples 1-4, it can be known that the modified nano-silica composite prepared by the present invention not only has the impermeability performance of silica, but also has a polycarboxylate water reducer containing graphene with freeze-thaw and impermeability performance. The inventor effectively combines the two to prepare a multifunctional modified nano-silica composite. After adding a polycarboxylate water reducer containing graphene to the concrete system, the number of capillary pores in the concrete can be greatly reduced, forming a highly dense microstructure of the concrete, further reducing the internal defects in the concrete, having good impermeability, high and low temperature resistance, and effectively hindering the migration of chloride ions; the modified nano-silica not only has improved hydrophobicity, but also has improved compatibility with other components of the epoxy resin matrix, can effectively prevent the penetration of water molecules, and at the same time further improves the compactness strength of the concrete, improves the pore structure, thereby reducing the penetration channels, and further greatly improving the freeze-thaw and impermeability performance of the concrete, thus effectively improving the durability of the bridge guardrail.

[0097] Further comparing Examples 4-5 shows that graphene oxide is introduced in the preparation of the polycarboxylate water reducer of the present invention. The reason is that graphene oxide can increase the yield of calcium silicate hydrate in concrete, promote the formation and arrangement of cement hydration crystals, improve the structure of the interface between the cement stone and the aggregate, reduce the porosity, and increase the density. While improving the microstructure, graphene oxide can also improve the compressive strength, tensile strength, impermeability, chloride ion erosion resistance, freeze-thaw resistance and other properties of concrete. It avoids the problem that directly adding the graphene oxide dispersion alone will cause large agglomerates to form due to long-term storage. After the agglomerated graphene oxide is incorporated into the concrete, it is unevenly distributed in the concrete, resulting in a large number of pores locally and causing a decline in the performance of the concrete.

[0098] Finally, comparing Example 4 and Example 6, in Example 6, hydroxybutyronitrile rubber modified epoxy resin is not added, and the effect will be relatively worse. The reason is that hydroxybutyronitrile rubber has a very polar -CN group, which can be well dispersed in the epoxy resin matrix during the prepolymerization reaction and the curing reaction, improving the toughness of the modified epoxy resin and thus improving the comprehensive performance of the concrete.

Claims

1. A nano-based antifreeze and anti-seepage gel, characterized in that: The invention is composed of group A and group B, wherein group A is composed of the following raw materials in parts by weight: 40-70 parts by weight of epoxy resin, 10-20 parts by weight of rubber-modified epoxy resin, 8-15 parts by weight of multifunctional epoxy resin, 2-7 parts by weight of dispersant, and 8-15 parts by weight of filler; group B is composed of the following raw materials in parts by weight: 3-8 parts by weight of corundum, 1-3 parts by weight of resistance increasing agent, 1-3 parts by weight of coupling agent, 4-8 parts by weight of toughening agent, 8-14 parts by weight of curing agent, 4-8 parts by weight of nano accelerator, and 6-10 parts by weight of functional additive, wherein the functional additive is a modified nano silicon dioxide composite; The preparation method of the modified nano-silicon dioxide composite is as follows; S1: 3-6 parts by weight of nano-silica and 40-60 parts by weight of ethanol aqueous solution are mixed, and ultrasonicated at a temperature of 35-50°C for 20-50 minutes; 0.8-2 parts by weight of silane coupling agent and 0.5-2 parts by weight of 20-30wt% ammonia water are added, and stirred at 30-50°C and 300-500rpm for 4-8 hours to obtain silane-modified nano-silica; S2, 2-6 parts by weight of acrylic acid, 3-7 parts by weight of 2-acrylic acid-2-hydroxy-1,3-propylene glycol, 20-40 parts by weight of methyl allyl alcohol polyoxyethylene ether and 60-120 parts by weight of water are uniformly mixed; 0.1-0.4 parts by weight of graphene oxide are added, and stirred at 20-40° C. and 300-500 rpm for 4-8 hours; then 0.3-0.8 parts by weight of thioglycolic acid and 0.3-0.8 parts by weight of ammonium persulfate are added; and the mixture is kept warm at 50-70° C. and 300-500 rpm for 1-4 hours to obtain a polycarboxylic acid water reducer containing graphene; S3, taking 2-5 parts by weight of the above-mentioned silane-modified nano-silica and 40-100 parts by weight of water, mixing them by ultrasound, adding 3-7 parts by weight of the above-mentioned polycarboxylate water-reducing agent containing graphene and 0.1-0.5 parts by weight of ammonium persulfate, stirring at 70-85° C. and 400-800 rpm for 50-90 min, and freeze-drying to obtain a modified nano-silica composite.

2. The nano-based antifreeze and anti-seepage gel according to claim 1, characterized in that: The weight ratio of group A to group B is (1.2-2.8):

1.

3. The nano-based antifreeze and anti-seepage gel according to claim 1, characterized in that: The multifunctional epoxy resin is at least one of polyphenol glycidyl ether epoxy resin, bisphenol A epoxy resin, hydrogenated bisphenol A epoxy resin, bisphenol S epoxy resin, and distyrene epoxy resin.

4. The nano-based antifreeze and anti-seepage gel according to claim 1, characterized in that: The dispersant is any one of sodium dodecylbenzene sulfonate, octylphenol polyoxyethylene ether, and fatty acid monoethanolamide; the filler is any one of silicon dioxide, calcium carbonate, talc, aluminum oxide, and montmorillonite; the retardant is at least one of cellulose hydroxypropyl methyl ether, fiber, and nonionic polyacrylamide; the coupling agent is one or any combination of silane coupling agent, titanate coupling agent, and aluminate coupling agent; the toughening agent is one or any combination of polyethylene glycol, polypropylene glycol, polyethylene glycol monomethyl ether, polyethylene glycol dimethyl ether, and tetraethylene glycol monooctyl ether; the curing agent is a fatty polyamine curing agent, an isocyanate curing agent, an acid anhydride curing agent, and an aromatic amine curing agent; and the nano accelerator is tetrabutylthiuram disulfide.

5. The nano-based antifreeze and anti-seepage gel according to claim 1, characterized in that: The preparation method of the rubber modified epoxy resin is as follows: under a nitrogen atmosphere, 3-6 parts by weight of terminal hydroxyl liquid nitrile rubber and 0.5-2 parts by weight of 2,4-toluene diisocyanate are mixed, and the mixture is reacted at 75-100° C. for 2-6 hours to obtain a prepolymer; 8-16 parts by weight of epoxy resin are added, heated to 90-110° C., and vacuumed and kept warm for 3-6 hours to obtain the rubber modified epoxy resin.

6. The nano-based antifreeze and anti-seepage gel according to claim 1, characterized in that: The silane coupling agent is at least one of 3-[bis(2-hydroxyethyl)amino]propane-triethoxysilane, N-(3-acryloxy-2-hydroxypropyl)-3-aminopropyltriethoxysilane, and N-(6-aminohexyl)aminomethyltriethoxysilane.

7. The method for preparing the nano-based antifreeze and anti-osmosis gel according to any one of claims 1 to 6, characterized in that: The steps include: (1) Weigh the raw materials of each component; (2) mixing epoxy resin, rubber-modified epoxy resin, multifunctional epoxy resin, dispersant and filler, and stirring at 40-60° C. and 4000-1000 rpm for 20-50 min to obtain component A; (3) Then stir the corundum, retardant, coupling agent, toughening agent and functional additive at room temperature and 1000-2000 rpm for 0.5-2h, finally add the curing agent and nano accelerator, and continue stirring for 15min to obtain component B; (4) Component A and component B are mixed and stirred evenly to obtain a nano-based antifreeze and anti-seepage gel.

8. Use of the nano-based antifreeze and anti-seepage gel according to any one of claims 1 to 6 in construction projects.

9. The use according to claim 8, characterized in that The nano-based antifreeze and anti-seepage gel is used as a repair material in construction engineering.