A self-leveling elastic microporous waterproof composite material and a preparation method thereof

Abstract

The application relates to the technical field of composite materials, and particularly discloses a self-leveling elastic microporous waterproof composite material and a preparation method thereof, the self-leveling elastic microporous waterproof composite material comprises the following raw materials in parts by weight: 90-110 parts of slag, 50-70 parts of polyurethane supermolecular emulsion, 1.4-1.8 parts of water glass, 5-10 parts of nano silicon sol, 1-3 parts of a composite foaming system, 2-4 parts of graphite powder, 1-2 parts of microcrystalline cellulose, 1-3 parts of a water reducing agent and 15-18 parts of deionized water; the composite foaming system is a composite foaming system of a chemical foaming agent and a physical foaming agent at a ratio of 2-4:1. The self-leveling elastic microporous waterproof composite material can be used in underground engineering, roof waterproofing, tunnel lining and other building and infrastructure fields with high requirements for waterproofness, elasticity and construction performance, and has good waterproofness and durability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of composite materials, in particular to a self-leveling elastic microporous waterproof composite material and a preparation method thereof. BACKGROUND

[0002] With the continuous improvement of urban underground space development, infrastructure construction and building energy saving requirements, waterproof materials as key functional materials to protect the safety and durability of the structure, their performance requirements are increasingly improved. Traditional waterproof materials such as asphalt-based rolls, cement-based permeable crystalline materials and ordinary polymer waterproof coatings, etc. have the problems of insufficient elasticity, easy cracking, low adhesion strength, poor dynamic deformation resistance and other problems in practical application, especially in the engineering environment with large temperature difference, frequent vibration or obvious uneven settlement, which is easy to cause damage to the waterproof layer due to stress concentration, and then cause leakage, which seriously affects the service life and safety of the project.

[0003] In recent years, elastic waterproof materials have gradually become a research hotspot. Among them, polyurethane waterproof coating is widely used due to its excellent elasticity, elongation and adhesion. However, conventional polyurethane materials still have defects such as poor heat resistance, easy aging under long-term service, low strength, etc., which are difficult to meet the needs of high-strength and high-durability waterproof engineering. In addition, the single organic system has high cost and limited adaptability to the base, which limits its large-scale promotion.

[0004] In order to improve the comprehensive performance, some studies try to combine polyurethane with inorganic cementitious materials to build an organic-inorganic hybrid system. For example, using industrial solid wastes such as slag and fly ash as inorganic framework, forming geopolymer through alkali activation, and then combining with polymer emulsion, aiming to combine the high strength of inorganic materials with the high elasticity of organic materials. However, such materials are prone to microcracks under low temperature or dynamic load, and the waterproof performance decreases.

[0005] Therefore, it is urgent to develop a new type of self-leveling elastic microporous waterproof composite material, which can not only realize good construction fluidity and self-leveling performance, but also form a closed microporous structure with high strength, high elasticity and low water absorption after solidification, and has excellent interfacial adhesion and long-term environmental stability. SUMMARY

[0006] In order to solve the above problems, the present application provides a self-leveling elastic microporous waterproof composite material and a preparation method thereof.

[0007] In the first aspect, the present application provides a self-leveling elastic microporous waterproof composite material, which adopts the following technical scheme:

[0008] A self-leveling elastic microporous waterproof composite material, comprising the following raw materials by weight:

[0009] Slag 90-110 parts, polyurethane supermolecular emulsion 50-70 parts, water glass 1.4-1.8 parts, nano-silica sol 5-10 parts, composite foaming system 1-3 parts, graphite powder 2-4 parts, microcrystalline cellulose 1-2 parts, water reducing agent 1-3 parts, deionized water 15-18 parts;The composite foaming system is a composite foaming system of chemical foaming agent and physical foaming agent in a mass ratio of 2-4:1.

[0010] By adopting the above technical scheme, the composite material obtained by the potential activity of slag in the alkaline environment provided by the water glass and the interpenetrating network structure formed by the synergy of the polyurethane supermolecular emulsion, gives the material excellent elasticity and bonding strength;Nano-silica sol further fills and densifies the microstructure, while the composite foaming agent forms a uniform and closed pore structure in the system through the synergistic effect of physical and chemical foaming, effectively blocking water penetration and absorbing stress. Graphite powder and microcrystalline cellulose together enhance the self-lubricating and cohesive properties of the material, and the water reducing agent ensures good flowability and self-leveling performance of the mixture. Finally, a waterproof material with good self-leveling and good mechanical properties is obtained.

[0011] Optionally, the physical foaming agent is a thermal expansion microsphere, and is mixed by low-temperature microspheres with an initial foaming temperature of 80-95℃ and high-temperature microspheres with an initial foaming temperature of 105-130℃ in a mass ratio of (6-8):(2-4).

[0012] By adopting the above technical scheme, the physical foaming agent is compounded by microspheres with different initial foaming temperatures, and its foaming behavior in the material curing process shows precise gradient and synergy. The low-temperature microspheres are first expanded by heat, and an initial supporting microporous skeleton is formed in the material, and then the high-temperature microspheres are expanded when the system temperature is further increased, which not only refines and perfects the pore structure formed, but also effectively repairs and supplements the defects that may be caused by resin shrinkage or chemical foaming. This step-by-step and continuous expansion process ensures the stable development of the pore structure during the entire film formation stage, and finally a three-dimensional closed pore network with more uniform pore size distribution and more dense and tough bubble wall structure is constructed, thereby significantly improving the elastic recovery rate, compressive strength and long-term durability of the composite material.

[0013] Optionally, the chemical foaming agent is a hydrogen peroxide solution with a mass concentration of 30%.

[0014] By adopting the technical scheme, a hydrogen peroxide solution with a specific concentration is selected as a chemical foaming agent, and a foaming mechanism thereof relies on controllable decomposition under catalysis of a basic system and trace metal ions to continuously and stably release oxygen. The mild decomposition and foaming process can be well matched with a coagulation and solidification rate of the material to avoid damage or connection of a pore structure caused by instantaneous and violent release of gas. The generated gas is uniformly overflowed in an elastic and cementitious framework formed by the polyurethane supermolecular emulsion and a hydration product of slag, and is complementary to and cooperates with a pore generated by a physical foaming agent to form a more delicate, uniform and non-connected closed pore structure. The cooperative foaming mechanism greatly enhances compactness and resilience of the material to ensure that the waterproof layer has excellent compression resilience and structural integrity when bearing dynamic stress.

[0015] Optionally, the polyurethane supermolecular emulsion is an aqueous emulsion formed by graft copolymerization of a fluorine-containing polyimide rigid segment and a polyurethane soft segment containing supermolecular hydrogen bonds through a chemical bond, and specifically includes the following preparation steps:

[0016] S1. Dissolve 2,2-bis(trifluoromethyl)-4,4'-diaminobiphenyl in N-methylpyrrolidone solvent, add pyromellitic dianhydride under the conditions of nitrogen protection and ice water bath, and stir to react for 2-6 h to obtain a polyamic acid solution; then add acetic anhydride, and gradually heat to 150-180℃ to react for 2-4 h; after the reaction is completed, add p-phenylenediamine, and react for 0.5-1 h to obtain a fluorine-containing polyimide oligomer (F-PI-NH2) solution with an amino group at the end;

[0017] S2. Dehydrate the polyether polyol under vacuum at 110-120℃ for 1-2 h; after cooling to 80-85℃, add diisocyanate and acetone, and react under nitrogen protection for 2-3 h to obtain an NCO group-terminated prepolymer; cool the system to 60-65℃, add 2,2-dimethylol propionic acid and N-aminoethylpiperazine, and react for 1-1.5 h to obtain an -NCO polyurethane prepolymer solution containing hydrogen bond sites;

[0018] S3. Add the F-PI-NH2 solution prepared in step S1 to the polyurethane prepolymer solution in step S2 under stirring, control the reaction temperature at 40-50℃, react for 1-2 h, add triethylamine, shear stir at 1000-1500 rpm, and slowly add deionized water; then add an ethylenediamine aqueous solution and react for 0.5-1 h; remove the solvent by reduced pressure distillation to obtain a polyurethane supermolecular emulsion.

[0019] By adopting the technical scheme, the polyurethane supermolecular emulsion introduces the rigid chain segment of fluorine-containing polyimide into the polyurethane soft chain segment network rich in supermolecular hydrogen bonds through a chemical bond by unique molecular structure design. The rigid chain segment of fluorine-containing polyimide serves as a powerful reinforcing phase, which significantly improves the tensile strength, heat resistance and durability of the film; and the rich supermolecular hydrogen bond network in the soft chain segment endows the material with excellent elasticity and deformation recovery ability. This stable structure of rigidity and flexibility enables the emulsion to form a dynamic physical crosslinking network after film formation, which not only produces firm interface combination with inorganic slag hydration products, but also enables the composite material to have high elasticity, toughness and excellent impermeability at the macro level, thereby greatly improving the overall mechanical properties and long-term service stability of the waterproof layer.

[0020] Optionally, the mass ratio of 2,2-bis(trifluoromethyl)-4,4'-diaminobiphenyl, pyromellitic dianhydride, acetic anhydride and p-phenylenediamine in S1 is 1:0.525:0.5-0.55:0.025-0.05;

[0021] The mass ratio of polyether polyol, diisocyanate, 2,2-dimethylol propionic acid and N-aminoethyl piperazine in S2 is 1:0.6-0.7:0.04-0.08:0.01-0.025;

[0022] The mass ratio of F-PI-NH2 solution to polyurethane prepolymer solution in S3 is 4-5:1, and the mass ratio of the amount of triethylamine to the mass of the polyurethane prepolymer solution is 0.02-0.03:1; the mass concentration of the ethylenediamine aqueous solution is 20%-40%, and the amount of the ethylenediamine aqueous solution is 1%-3% of the amount of the polyurethane prepolymer solution.

[0023] Optionally, the water reducing agent is a polycarboxylic acid type high efficiency water reducing agent.

[0024] By adopting the technical scheme, the polycarboxylic acid type high efficiency water reducing agent produces strong steric hindrance and electrostatic pressure effect in the slurry through its unique comb-shaped molecular structure, which can effectively destroy the flocculation structure between particles and fully release the wrapped free water. This action significantly improves the fluidity of the composite slurry and the self-leveling effect during construction, so that a highly compact base can be formed at a very low water-cement ratio. This not only reduces the pores left by water evaporation from the source, enhances the waterproof and impermeability, but also ensures that the chemical and physical foaming processes can be carried out in a more stable and uniform gel environment, thereby synergistically constructing a microcellular structure with excellent strength and elasticity, and finally endowing the waterproof layer with excellent compactness and durability.

[0025] Optionally, the raw material further includes 0.5-1.5 parts of nano graphene with a specific surface area greater than 500 m 2 / g.

[0026] By adopting the technical scheme, nanoscale pores can be effectively filled in the slurry, and the compactness of the matrix is greatly improved. More importantly, the graphene sheet layer can be staggered and spread in the three-dimensional network formed by the polymer and inorganic hydration product, forming a dense physical barrier, greatly delaying the penetration path of water and erosive medium. At the same time, its excellent mechanical properties and flexibility provide additional bridging and toughening effect for the composite material, significantly enhancing the toughness and crack resistance of the micro-porous structure, so that the waterproof layer has better crack following ability and long-term structural stability under dynamic stress, thereby comprehensively improving the durability and waterproof performance.

[0027] In a second aspect, the application provides a preparation method of a self-leveling elastic micro-porous waterproof composite material, which adopts the following technical scheme:

[0028] A preparation method of a self-leveling elastic micro-porous waterproof composite material, comprising the following steps:

[0029] S1. Preparation of a premix liquid: mix the polyurethane supermolecular emulsion and the water reducing agent, and stir at a speed of 300-500 r / min for 2-4 min to obtain liquid A; mix the nano-silica sol and deionized water, and ultrasonically disperse for 5-10 min to obtain a suspension;

[0030] S2. High-shear emulsification mixing: mix the liquid A and the suspension, and emulsify at a high shear rate of 4000-6000 r / min for 1-3 min; then add the slag, graphite powder and microcrystalline cellulose, and stir at a speed of 600-800 r / min for 3-5 min to obtain a basic slurry;

[0031] S3. Foaming and pouring: add the alkaline activator solution and the composite foaming system to the basic slurry obtained in step S2, and high-speed stir at a speed of 800-1000 r / min for 30-60 s to obtain a foaming slurry; immediately pour the foaming slurry into a mold and cure to form a shape.

[0032] By adopting the technical scheme, first, the high-molecular emulsion, nano-particles and functional additives form a stable and homogeneous dispersion system through premixing and high-shear emulsification, laying a foundation for the formation of a composite structure; then, the solid fillers are introduced under mild stirring, avoiding damage to the formed structure caused by excessive shearing, and ensuring the stability of the slurry; finally, the alkaline activator triggers the hydration reaction of the slag, and the high-speed stirring triggers the composite foaming system, so that the generation and expansion of bubbles and the condensation and solidification of the slurry are accurately synchronized and coordinated. The precise control of the timing and dynamics ultimately promotes the symbiosis of the organic high-molecular network, inorganic hydration product and uniformly distributed micro-porous structure, thereby perfectly realizing the high unification of the material elasticity, sealing property and self-leveling characteristics.

[0033] In summary, the present application has the following beneficial effects:

[0034] 1、The present application realizes the synergistic enhancement of material elasticity, compactness and micro-porous structure by constructing organic-inorganic interpenetrating network under alkaline activation of polyurethane supramolecular emulsion and slag, and combining with composite foaming system. Especially, the introduction of fluorine-containing polyimide rigid chain segment and supramolecular hydrogen bond soft segment copolymerized emulsion, and the gradient foaming physical and chemical composite foaming technology, makes the material form uniform closed cell structure in microcosm, and shows the beneficial effects of high elasticity and strong toughness in macrocosm.

[0035] 2、In the present application, the introduction of multi-scale functional components such as nano-graphene and nano-silica sol significantly improves the compactness and barrier properties of the material. The two-dimensional sheet structure of graphene interlaces in the matrix to form an efficient permeation barrier, which cooperates with microcrystalline cellulose and graphite powder to enhance the cohesion and self-lubricity, and the polycarboxylic acid-based water reducing agent ensures the high fluidity and low water-binder ratio of the mixture, thereby overall strengthening the impermeability and durability of the waterproof layer.

[0036] 3、The method of the present application realizes the uniform dispersion and structure ordered construction of each component by combining the mixing strategies of step-by-step feeding, step-by-step stirring and high shear emulsification. This method makes the foaming process and the slurry condensation and solidification rate match well, promotes the stable formation of bubbles in the elastic gel skeleton, and finally realizes the synergistic symbiosis of micro-porous structure, polymer network and inorganic hydration product, so that the material has good construction fluidity, self-leveling property and high strength and high elasticity after forming. DETAILED DESCRIPTION

[0037] The present application is further described in detail below in conjunction with examples, and it is particularly pointed out that: in the following examples, the specific conditions are not specified, and the conventional conditions or the conditions recommended by the manufacturer are used, and the raw materials used in the following examples can be obtained from ordinary market sales unless otherwise specified.

[0038] The thermal expansion microspheres are purchased from Dongguan Weijie New Material Co., Ltd., the low-temperature microspheres have an initial foaming temperature of 80-95℃, and the density is ≤12 kg / m 3 The high-temperature microspheres have an initial foaming temperature of 116-126℃, and the density is ≤20 kg / m 3 The nano-silica sol is purchased from Qinghe County Chaotai Metal Material Co., Ltd., the model number is ZT-SP15W, and the particle size is 15 nm; the slag is purchased from Suzhou Jiuda New Material Technology Co., Ltd., the density is 1.32 g / cm 3 , and the specific surface area is 400-450 m 2kg; graphite powder was purchased from Shenzhen Hanhui Graphite Co., Ltd., flake shape; microcrystalline cellulose was purchased from Shanghai Fuxi Industry and Trade Co., Ltd., item No. 58956; polyurethane emulsion was purchased from Weifang Dexiang Waterproof Material Co., Ltd., elongation at break 200%.

[0039] Preparation examples of raw materials and / or intermediates

[0040] Preparation example 1

[0041] A polyurethane supramolecular emulsion, the preparation comprising the following steps:

[0042] S1. 20 kg of 2,2-bis(trifluoromethyl)-4,4'-diaminobiphenyl was dissolved in 120 kg of N-methylpyrrolidone solvent, 10.5 kg of pyromellitic dianhydride was added under the condition of nitrogen protection and ice water bath, and stirred for 4 h to obtain a polyamic acid solution; then 10.5 kg of acetic anhydride was added, and gradually heated to 165°C for 3 h; after the reaction was completed, 0.7 kg of p-phenylenediamine was added, and reacted for 0.75 h to obtain a fluorine-containing polyimide oligomer (F-PI-NH2) solution with an amino group at the end, with a solid content of 18-22%;

[0043] S2. 20 kg of polyether polyol was dehydrated at 110-120°C under vacuum for 1.5 h; after cooling to 85°C, 13 kg of diisocyanate and 6 kg of acetone were added, and reacted for 2.5 h under nitrogen protection to obtain an NCO group terminated prepolymer; the system was cooled to 62.5°C, 1.2 kg of 2,2-dimethylol propionic acid and 0.35 kg of N-aminoethylpiperazine were added, and reacted for 1-1.5 h to obtain an -NCO polyurethane prepolymer solution containing hydrogen bonding sites;

[0044] S3. 90 kg of F-PI-NH2 solution prepared in step S1 was added to 20 kg of polyurethane prepolymer solution in step S2 under stirring, and the reaction temperature was controlled at 45°C, reacted for 1-2 h, 0.5 kg of triethylamine was added, and sheared and stirred at 1250 rpm, and deionized water was slowly added until the solid content was between 30-40%; then 1 kg of ethylenediamine aqueous solution was added and reacted for 0.75 h; acetone and N-methylpyrrolidone were removed by distillation under reduced pressure to obtain a polyurethane supramolecular emulsion.

[0045] Preparation example 2

[0046] A polyurethane supramolecular emulsion, the preparation comprising the following steps:

[0047] S1. 20 kg of 2,2-bis(trifluoromethyl)-4,4'-diaminobiphenyl was dissolved in 144 kg of N-methylpyrrolidone solvent, 10.5 kg of pyromellitic dianhydride was added under nitrogen protection and ice water bath conditions, and stirred for 2 h to obtain a polyamic acid solution; then 10 kg of acetic anhydride was added, and gradually heated to 150°C for 4 h; after the reaction was completed, 0.5 kg of p-phenylenediamine was added, and reacted for 0.5 h to obtain a fluorine-containing polyimide oligomer (F-PI-NH2) solution with an amino group at the end, with a solid content of 18-22%;

[0048] S2. 20 kg of polyether polyol was dehydrated at 110-120°C under vacuum for 1-2 h; after cooling to 80°C, 14 kg of diisocyanate and 4 kg of acetone were added, and reacted for 3 h under nitrogen protection to obtain an NCO group terminated prepolymer; the system was cooled to 60°C, 0.8 kg of 2,2-dimethylol propionic acid and 0.2 kg of N-aminoethylpiperazine were added, and reacted for 1 h to obtain an -NCO polyurethane prepolymer solution containing hydrogen bonding sites;

[0049] S3. 80 kg of F-PI-NH2 solution prepared in step S1 was added to 20 kg of polyurethane prepolymer solution in step S2 under stirring, and the reaction temperature was controlled at 40°C, reacted for 2 h, 0.4 kg of triethylamine was added, and sheared and stirred at 1000 rpm, and deionized water was slowly added to a solid content of 30-40%; then 1.2 kg of ethylenediamine aqueous solution was added and reacted for 0.5 h; acetone and N-methylpyrrolidone were removed by distillation under reduced pressure to obtain a polyurethane supramolecular emulsion.

[0050] Preparation Example 3

[0051] A polyurethane supramolecular emulsion, the preparation comprising the following steps:

[0052] S1. 20 kg of 2,2-bis(trifluoromethyl)-4,4'-diaminobiphenyl was dissolved in 144 kg of N-methylpyrrolidone solvent, 10.5 kg of pyromellitic dianhydride was added under nitrogen protection and ice water bath conditions, and stirred for 2 h to obtain a polyamic acid solution; then 10 kg of acetic anhydride was added, and gradually heated to 150°C for 4 h; after the reaction was completed, 0.5 kg of p-phenylenediamine was added, and reacted for 0.5 h to obtain a fluorine-containing polyimide oligomer (F-PI-NH2) solution with an amino group at the end, with a solid content of 18-22%;

[0053] S2. Dehydrate 20 kg polyether polyol at 120 °C under vacuum for 1 h; after cooling to 85 °C, add 12 kg diisocyanate and 8 kg acetone, and react under nitrogen protection for 3 h to obtain an NCO group terminated prepolymer; cool the system to 65 °C, add 1.6 kg 2,2-dimethylol propionic acid and 0.5 kg N-aminoethyl piperazine, and react for 1.5 h to obtain an NCO group terminated polyurethane prepolymer solution containing hydrogen bonding sites;

[0054] S3. Take 100 kg of the F-PI-NH2 solution prepared in step S1 and add it to 20 kg of the polyurethane prepolymer solution prepared in step S2 under stirring, control the reaction temperature at 50 °C, react for 1 h, add 0.6 kg of triethylamine, and shear stir at 1500 rpm; slowly add deionized water until the solid content is between 30-40%; then add 0.8 kg of an ethylenediamine aqueous solution and react for 1 h; remove acetone and N-methyl pyrrolidone by distillation under reduced pressure to obtain a polyurethane supramolecular emulsion.

[0055] Example

[0056] Example 1

[0057] A self-leveling elastic microporous waterproof composite material, the preparation comprising the following steps:

[0058] S1. Pre-mixed liquid preparation: mix 60 kg of the polyurethane supramolecular emulsion prepared in Preparation Example 1 with 2 kg of a polycarboxylic acid superplasticizer, and stir at 400 r / min for 3 min to obtain liquid A; mix 7.5 kg of a nano-silica sol with 17 kg of deionized water, and ultrasonically disperse for 7.5 min to obtain a suspension;

[0059] S2. High-shear emulsification mixing: mix liquid A and the suspension, and emulsify at a high shear rate of 5000 r / min for 2 min; then add 100 kg of slag, 3 kg of graphite powder, and 1.5 kg of microcrystalline cellulose, and stir at 700 r / min for 4 min to obtain a base slurry;

[0060] S3. Foaming and casting: add 1.6 kg of water glass and 2 kg of a composite foaming system to the base slurry obtained in step S2, and high-speed stir at 900 r / min for 45 s to make it preliminarily foam to obtain a foamed slurry; immediately pour the foamed slurry into a mold and cure to form; the composite foaming system comprises 1.5 kg of a physical foaming agent mixed at a mass ratio of 7:3 and 0.5 kg of a 30% mass concentration hydrogen peroxide solution.

[0061] Example 2

[0062] A self-leveling elastic microporous waterproof composite material, the preparation comprising the following steps:

[0063] S1. Preparation of premix liquid: 50 kg of the polyurethane supramolecular emulsion prepared in Preparation Example 2 was mixed with 1 kg of polycarboxylate superplasticizer, stirred at a speed of 300 r / min for 4 min to obtain liquid A; 10 kg of nano-silica sol was mixed with 15 kg of deionized water and ultrasonically dispersed for 5 min to obtain a suspension;

[0064] S2. High-shear emulsification mixing: liquid A and the suspension were mixed and emulsified at a high shear rate of 4000 r / min for 1 min; then 110 kg of slag, 1 kg of graphite powder and 2 kg of microcrystalline cellulose were added and stirred at a speed of 600 r / min for 5 min to obtain a base slurry;

[0065] S3. Foaming and casting: 1.4 kg of water glass and 3 kg of a composite foaming system were added to the base slurry obtained in step S2, and high-speed stirring was performed at a speed of 800 r / min for 60 s to make it preliminarily foam to obtain a foamed slurry; the foamed slurry was immediately cast into a mold and cured to form a product; the composite foaming system included 2 kg of a physical foaming agent mixed at a mass ratio of 7:3 and 1 kg of a hydrogen peroxide solution with a mass concentration of 30%.

[0066] Example 3

[0067] A self-leveling elastic microporous waterproof composite material, the preparation comprising the following steps:

[0068] S1. Preparation of premix liquid: 70 kg of the polyurethane supramolecular emulsion prepared in Preparation Example 3 was mixed with 3 kg of polycarboxylate superplasticizer, stirred at a speed of 500 r / min for 4 min to obtain liquid A; 5 kg of nano-silica sol was mixed with 18 kg of deionized water and ultrasonically dispersed for 10 min to obtain a suspension;

[0069] S2. High-shear emulsification mixing: liquid A and the suspension were mixed and emulsified at a high shear rate of 6000 r / min for 1 min; then 90 kg of slag, 4 kg of graphite powder and 1 kg of microcrystalline cellulose were added and stirred at a speed of 800 r / min for 3 min to obtain a base slurry;

[0070] S3. Foaming and casting: 1.8 kg of water glass and 1 kg of a composite foaming system were added to the base slurry obtained in step S2, and high-speed stirring was performed at a speed of 1000 r / min for 30 s to make it preliminarily foam to obtain a foamed slurry; the foamed slurry was immediately cast into a mold and cured to form a product; the composite foaming system included 0.8 kg of a physical foaming agent mixed at a mass ratio of 7:3 and 0.2 kg of a hydrogen peroxide solution with a mass concentration of 30%.

[0071] Example 4

[0072] A self-leveling elastic microporous waterproof composite material, different from example 1 is that only low-temperature microspheres are added in the physical foaming agent in this example.

[0073] Example 5

[0074] A self-leveling elastic microporous waterproof composite material, different from example 1 is that only high-temperature microspheres are added in the physical foaming agent in this example.

[0075] Example 6

[0076] A self-leveling elastic microporous waterproof composite material, different from example 1 is that 0.5 kg of nano-graphene is further included in this example, comprising the following steps:

[0077] S1. Preparation of a premix liquid: 60 kg of polyurethane supermolecular emulsion is mixed with 2 kg of polycarboxylic acid superplasticizer, stirred at a speed of 400 r / min for 3 minutes to obtain liquid A; 7.5 kg of nano-silica sol is mixed with 17 kg of deionized water and ultrasonically dispersed for 7.5 min to obtain a suspension;

[0078] S2. High-shear emulsification mixing: liquid A and the suspension are mixed and emulsified at a high shear rate of 500 r / min for 2 minutes; then 100 kg of slag, 3 kg of graphite powder, 1.5 kg of microcrystalline cellulose, and 0.5 kg of nano-graphene are added, and stirred at a speed of 700 r / min for 4 minutes to obtain a base slurry;

[0079] S3. Foaming and pouring: 1.6 kg of water glass and 2 kg of a composite foaming system are added to the base slurry obtained in step S2, and high-speed stirring is performed at a speed of 900 r / min for 45 seconds to make it initially foam to obtain a foaming slurry; the foaming slurry is immediately poured into a mold and cured to form; the composite foaming system includes 1.5 kg of a physical foaming agent mixed at a mass ratio of 7:3 and 0.5 kg of a hydrogen peroxide solution with a mass concentration of 30%.

[0080] Example 7

[0081] A self-leveling elastic microporous waterproof composite material, different from example 6 is that 1 kg of nano-graphene is added in this example.

[0082] Example 8

[0083] A self-leveling elastic microporous waterproof composite material, different from example 6 is that 1.5 kg of nano-graphene is added in this example.

[0084] Comparative example

[0085] Comparative example 1

[0086] A self-leveling elastic microporous waterproof composite material, which is different from Example 1 in that a commercially available polyurethane emulsion is used in the same amount instead of the polyurethane supramolecular emulsion in the present comparative example.

[0087] Comparative Example 2

[0088] A self-leveling elastic microporous waterproof composite material, which is different from Example 1 in that no composite foaming system is added in the present comparative example.

[0089] Performance detection test

[0090] Detection method / test method

[0091] Compressive strength: The compressive strength of the test sample is detected according to GB / T 50081-2019 "Standard Test Methods of Physical and Mechanical Properties of Concrete";

[0092] Water absorption: detected according to GB / T 5486-2008 "Test Methods of Inorganic Hard Insulation Products" by vacuum saturation method;

[0093] Elongation at break: tested according to "GB / T 528-2009 Determination of Tensile Stress-Strain Properties of Vulcanized or Thermoplastic Rubber";

[0094] Durability: long-term water immersion stability test is carried out, and the compressive strength is detected after water curing for 28 days, and the strength retention rate is obtained by test.

[0095] Table 1 Test Detection Data

[0096]

[0097] It can be seen from Examples 1-3 and Comparative Example 1 in combination with Table 1 that the experimental data of Examples 1-3 are all better than those of Comparative Example 1. The fluorine-containing polyimide-supramolecular polyurethane emulsion specially prepared in the present application can significantly improve the mechanical strength of the composite material, reduce the water absorption rate and improve the waterproof performance compared with the ordinary polyurethane emulsion on the market. This is due to the synergistic enhancement effect of F-PI rigid chain segment and PU hydrogen bond network, forming a more dense and elastic organic-inorganic interpenetrating network structure, thereby greatly improving the overall performance of the material.

[0098] It can be seen from Examples 1-3 and Comparative Example 2 in combination with Table 1 that although Comparative Example 2 maintains good compressive strength, its water absorption rate is significantly increased, and the strength retention rate after freeze-thaw is greatly decreased, indicating that its structure is dense but brittle, and the environmental stress resistance is poor. After introducing the composite foaming system, the material maintains high strength while forming a uniform closed-cell microporous structure, effectively blocking water penetration and absorbing internal stress, significantly improving the waterproofness, elasticity and long-term durability of the material, and realizing the synergistic optimization of "strong and tough waterproofness".

[0099] As can be seen from the combination of Example 1 and Examples 4-5 and Table 1, the test data of Example 1 is better than that of Examples 4-5, indicating that the gradient foaming strategy of compounding low-temperature and high-temperature thermal expansion microspheres can realize step-by-step and continuous pore structure evolution compared with microspheres of a single foaming temperature: low-temperature microspheres form an initial pore skeleton first, and high-temperature microspheres then perform secondary filling and refinement, effectively repairing defects and improving the density of the bubble wall, thereby constructing a more uniform and higher-closed three-dimensional microporous network. This synergistic foaming mechanism significantly improves the compactness, resilience and waterproof performance of the material, verifying the necessity and superiority of the composite physical foaming design.

[0100] As can be seen from the combination of Example 1 and Examples 6-8 and Table 1, the test data of Examples 6-8 is better than that of Example 1, indicating that the addition of nano-graphene can further significantly improve the compactness and durability of the composite material. Nano-graphene, with its ultra-high specific surface area and two-dimensional sheet structure, forms a dense "labyrinth" barrier in the matrix, effectively inhibiting the penetration path of water and erosion medium; at the same time, its excellent mechanical properties and flexibility play a bridging and toughening role for the microporous wall, inhibiting the expansion of micro-cracks, thereby further reducing the water absorption rate, reducing the strength loss after immersion, and improving the strength retention rate of the material.

[0101] The specific embodiments are merely an explanation of the present application, which is not a limitation of the present application. Those skilled in the art can make modifications to the embodiments without creative contribution after reading the present specification, but as long as the modifications are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A self-leveling, resilient, microporous, waterproof composite material, characterized in that, The raw materials include the following weight parts: slag 90-110 parts, polyurethane supermolecular emulsion 50-70 parts, water glass 1.4-1.8 parts, nano silicon sol 5-10 parts, composite foaming system 1-3 parts, graphite powder 2-4 parts, microcrystalline cellulose 1-2 parts, water reducing agent 1-3 parts, and deionized water 15-18 parts; the composite foaming system is a composite foaming system of a chemical foaming agent and a physical foaming agent at a mass ratio of 2-4:1; The polyurethane supermolecular emulsion is an aqueous emulsion formed by graft copolymerization of a fluorine-containing polyimide rigid segment and a polyurethane soft segment containing supermolecular hydrogen bonds through a chemical bond, and specifically includes the following preparation steps: S1. 2,2-bis(trifluoromethyl)-4,4'-diaminobiphenyl is dissolved in N-methylpyrrolidone solvent, and under nitrogen protection and ice water bath conditions, pyromellitic dianhydride is added, and stirring is performed for 2-6 h to obtain a polyamic acid solution; then acetic anhydride is added, and the temperature is gradually increased to 150-180°C, and the reaction is maintained for 2-4 h; after the reaction is completed, p-phenylenediamine is added, and the reaction is continued for 0.5-1 h to obtain a fluorine-containing polyimide oligomer (F-PI-NH2) solution with an amino group at the end; S2. The polyether polyol is dehydrated under vacuum at 110-120°C for 1-2 h; after cooling to 80-85°C, diisocyanate and acetone are added, and the reaction is performed under nitrogen protection for 2-3 h to obtain an NCO group-terminated prepolymer; the system is cooled to 60-65°C, 2,2-dimethylolpropionic acid and N-aminoethylpiperazine are added, and the reaction is performed for 1-1.5 h to obtain an -NCO polyurethane prepolymer solution containing hydrogen bond sites; S3. The F-PI-NH2 solution prepared in step S1 is added to the polyurethane prepolymer solution of step S2 under stirring, the reaction temperature is controlled at 40-50°C, the reaction is performed for 1-2 h, triethylamine is added, and deionized water is slowly added under shearing stirring at 1000-1500 rpm; then ethylenediamine aqueous solution is added and the reaction is performed for 0.5-1 h; the solvent is removed by reduced pressure distillation to obtain a polyurethane supermolecular emulsion; The physical foaming agent is a thermal expansion microsphere, and is formed by mixing low-temperature microspheres with an initial foaming temperature of 80-95°C and high-temperature microspheres with an initial foaming temperature of 105-130°C at a mass ratio of (6-8):(2-4); The chemical foaming agent is a 30% mass concentration hydrogen peroxide solution.

2. A self-leveling, resilient, microporous, waterproof composite material according to claim 1, characterized in that: The mass ratio of 2,2-bis(trifluoromethyl)-4,4'-diaminobiphenyl, pyromellitic dianhydride, acetic anhydride, and p-phenylenediamine in S1 is 1:0.525:0.5-0.55:0.025-0.05; The mass ratio of polyether polyol, diisocyanate, 2,2-dimethylolpropionic acid, and N-aminoethylpiperazine in S2 is 1:0.6-0.7:0.04-0.08:0.01-0.025; The mass ratio of the F-PI-NH2 solution in S3 to the polyurethane prepolymer solution is 4-5:1, the ratio of the amount of triethylamine to the mass of the polyurethane prepolymer solution is 0.02-0.03:1; the mass concentration of the ethylenediamine aqueous solution is 20%-40%, and the amount of the ethylenediamine aqueous solution is 1%-3% of the amount of the polyurethane prepolymer solution.

3. A self-leveling, resilient, microporous, waterproof composite material according to claim 1, characterized in that: The water reducing agent is a polycarboxylic acid high-efficiency water reducing agent.

4. The self-leveling, resilient, microporous, waterproof composite material of claim 1, wherein: The raw material also includes 0.5-1.5 parts of nano-graphene with a specific surface area greater than 500 m 2 / g.

5. A process for the preparation of a self-leveling, elastic, microporous, waterproof composite material according to any one of claims 1-4, characterized in that, The method comprises the following steps: S1. Preparation of a premix solution: mixing a polyurethane supermolecular emulsion and a water reducing agent, stirring at a speed of 300-500 r / min for 2-4 min to obtain A liquid; mixing a nano-silica sol and deionized water, and ultrasonic dispersing for 5-10 min to obtain a suspension; S2. High-shear emulsification mixing: mixing the A liquid and the suspension, and emulsifying at a high shear rate of 4000-6000 r / min for 1-3 min; then adding slag, graphite powder and microcrystalline cellulose, and stirring at a speed of 600-800 r / min for 3-5 min to obtain a basic slurry; S3. Foaming and pouring: adding an alkaline activator solution and a composite foaming system to the basic slurry obtained in step S2, and stirring at a high speed of 800-1000 r / min for 30-60 s to obtain a foamed slurry; immediately pouring the foamed slurry into a mold and curing to form a product.

Images