Multifunctional composite material as well as preparation method and application thereof

Abstract

The invention discloses a multifunctional composite material and a preparation method and application thereof, and belongs to the technical field of composite materials. The multifunctional composite material provided by the invention is suitable for industrial scenes which need to meet the requirements of corrosion resistance, buoyancy support, light heat preservation and safety protection at the same time. Comprising but not limited to the fields of passive energy absorption protection, petrochemical engineering storage and transportation facilities, deep sea detection equipment, structure filling engineering in flammable and explosive environments, acoustic noise reduction engineering and the like. The multifunctional composite material provided by the invention is a material with multi-environment adaptability, and is particularly suitable for a composite functional material system with the characteristics of water resistance, oil resistance, chemical corrosion resistance, low heat conductivity, flame retardance, high-temperature adaptability, sound absorption, noise reduction and structural lightweight.

Description

Technical Field

[0001] This invention belongs to the field of composite material technology, and in particular relates to a multifunctional composite material, its preparation method and application. Background Technology

[0002] Currently, in the field of composite materials, there are still many technical limitations in material design for applications in complex environments:

[0003] 1. Limitations of waterproof, oil-resistant, and acid / alkali-corrosion-resistant properties:

[0004] In the lining protection of petrochemical storage tanks, glass fiber reinforced epoxy resin (GFRP), which is widely used, has good resistance to strong acids such as hydrochloric acid and sulfuric acid (and can withstand environments with pH=1-3). However, when exposed to crude oil or aromatic organic solvents for a long time, its mechanical properties will drop sharply due to the swelling of the resin matrix. For example, a refinery storage tank with a GFRP lining experienced a decrease in interlaminar shear strength in the diesel-immersed area after 18 months of operation, from the initial 78 MPa to 42 MPa (a decrease of 46%), and obvious delamination was observed. This is because the ether bonds in the epoxy resin molecular chain are easily penetrated by non-polar oil molecules, destroying the cross-linked network structure. Existing technologies, such as adding coupling agents (e.g., KH-550), can only extend the oil resistance life to 24-30 months, which still cannot meet the 20-year design life requirement of the storage tank.

[0005] Polyester-based polyurethane elastomers (PCL-PU), widely used in building waterproofing projects, can withstand alkaline environments with pH values ​​of 10-12 (such as concrete curing solutions), but their ester bonds break when immersed in strong acids (pH 1-2). Studies have shown that after immersion in a 10wt% hydrochloric acid solution for 30 days, the tensile strength of PCL-PU drops from 35 MPa to 12 MPa, the elongation at break drops from 450% to 120%, and dense cracks appear on the surface. For example, in a chemical plant workshop where PCL-PU coatings were used, blistering and peeling occurred in the corroded areas within 24 hours after a sulfuric acid leak, with repair costs reaching three times the original construction cost. In contrast, while polyether-based polyurethane (PBA-PU) can extend acid resistance to 90 days, its alkali resistance decreases by 30%, failing to meet the complex requirements of chemical workshops where both acid and alkali corrosion exist simultaneously.

[0006] 2. Limitations of low thermal conductivity, lightweight design, and sound absorption / noise reduction:

[0007] Centrifugal glass wool: Glass wool has an open-cell, porous structure, with a sound absorption coefficient of 0.8-1.0 (excellent sound absorption) at 500-2000Hz, and a density of only 16-24kg / m³. 3(Lightweight design is a key feature); however, the air convection in the open structure intensifies heat conduction, resulting in a thermal conductivity of 0.042-0.048 W / (m·K), which barely meets the standard. Furthermore, after absorbing water (such as during the rainy season), the thermal conductivity rises sharply to 0.07-0.08 W / (m·K) (thermal resistance decreases by 50%), and its strength is extremely low (<0.08 MPa). It cannot be used directly as an exterior wall surface layer and requires an additional cement mortar protective layer (increasing the wall load by 30%, which contradicts the original intention of lightweight design). Moreover, it is prone to powdering and peeling after long-term use.

[0008] Traditional composite materials, such as aluminum honeycomb / epoxy composite panels, use an aluminum skin + aluminum honeycomb core structure, with an areal density of only 3-5 kg / m³. 2 The honeycomb core's closed-cell cavity blocks heat conduction, with a thermal conductivity of 0.038-0.045 W / (m·K). Due to the presence of a large 5-10 mm sealed cavity inside, its sound absorption frequency band is extremely narrow, and it can only absorb high-frequency noise from motors above 1500 Hz through air resonance within the cavity, with a sound absorption coefficient of 0.3-0.4. The sound absorption coefficient for low-frequency noise (<200 Hz) is <0.1.

[0009] 3. Limitations in flame retardancy and high-temperature adaptability:

[0010] Existing market resin and plastic organic composite materials have significant shortcomings in flame retardancy and high-temperature adaptability, and these problems become increasingly apparent in real-world scenarios. For example, glass fiber reinforced epoxy resin (GFRP) at temperatures above 80°C will accelerate the penetration rate of aromatic solvents in crude oil by 2-3 times, resulting in noticeable delamination within just 3-6 months, with corrosion depth increasing by 50% compared to room temperature, and repair costs reaching 40%-60% of the initial construction cost. Polyester-based polyurethane (PCL-PU) softens at 60°C, and its tensile strength decreases by more than 50% at 120°C. Furthermore, it remains unrecovered in 10wt% hydrochloric acid at 60°C for 15 days. The tensile strength drops below 10 MPa, the surface crack density is three times that at room temperature, and the peeling area reaches twice that at room temperature within 24 hours when high temperature and corrosion are combined. The alkali resistance of polyether polyurethane (PBA-PU) will decrease by another 40% at high temperature. These organic materials generally have low ignition points (epoxy resin is about 420℃, polypropylene (PP) is about 380℃). Materials containing polybrominated diphenyl ethers (PBDEs) release dioxins when burned (violating GB / T26572), PVC releases hydrogen chloride when burned, and epoxy resin releases benzene compounds when burned (the benzene concentration in a confined space can reach 10 mg / m³ in 5 minutes). 3 The peak heat release rate of PP combustion reaches 600 kW / m³. 2The smoke density rating (SDR) is 80, and some materials produce molten drips at temperatures above 300°C during combustion, which can easily cause secondary fires. Furthermore, when exposed to environments of 50-100°C for extended periods, the oxygen index of PVC drops from 32% to below 26% after 3 months (below the 28% requirement of the flame retardant standard); the oxygen index of flame-retardant PP drops from 30% to 25% and its horizontal flammability rating drops from V-0 to V-2 after 6 months; the elongation at break of PCL-PU drops from 450% to below 100% after 6 months at 80°C; and the impact strength of GFRP after 12 months of contact with crude oil at 60°C drops from 120kJ / m². 2 Reduced to 50 kJ / m 2 The flame retardant properties and mechanical properties collapse simultaneously. Summary of the Invention

[0011] To address the aforementioned technical problems, this invention proposes a multifunctional composite material, its preparation method, and its applications.

[0012] To achieve the above objectives, the present invention provides the following technical solution:

[0013] This invention provides a multifunctional composite material comprising the following raw materials: lightweight aggregate, lightweight filler, cementitious material, surface treatment agent, additives, and water;

[0014] The lightweight aggregate is composed of four of the following: fly ash cenospheres, nitrile rubber powder, foam glass cutting waste powder, pre-degreased rapeseed, aerogel powder, expanded vermiculite, lightweight ceramsite powder, closed-cell perlite, bamboo and wood chips, vanadium-titanium steel slag, chopped straw, diatomite, and expanded perlite, combined with expanded graphite and hollow glass microspheres.

[0015] The lightweight filler is composed of one of lithium slag, silica, desulfurized gypsum and talc powder, combined with lightweight calcium carbonate, gypsum dihydrate and bentonite.

[0016] The cementitious material is composed of two of the following: blast furnace water-quenched slag, magnesium phosphate cement, silica sol, alkali-activated cement, magnesium oxychloride cement, and blast furnace water-quenched slag cement, combined with silicate cement, early-strength sulfoaluminate cement, and mineral powder.

[0017] The surface treatment agent is selected from five of the following: silane coupling agent isopropanol or anhydrous ethanol solution, sodium methylsilicate aqueous solution, polyamide resin xylene solution, chloroprene rubber latex aqueous solution, silicone acrylic latex anhydrous ethanol solution, styrene acrylic latex aqueous solution, and fluorocarbon latex acetone or toluene solution.

[0018] The additive is composed of at least one of aluminum sulfate, sodium aluminate, lithium salt, sulfate expanding agent and hydrated calcium silicate whiskers, combined with a water reducing agent and an organosilicon defoamer.

[0019] For example, lightweight aggregates are selected from expanded graphite, hollow glass microspheres, nitrile rubber powder, fly ash cenospheres, foam glass cutting waste powder, and pre-de-oiled rapeseed; lightweight aggregates are selected from expanded graphite, hollow glass microspheres, aerogel powder, nitrile rubber powder, expanded vermiculite, and lightweight ceramsite powder; lightweight aggregates are selected from expanded graphite, hollow glass microspheres, fly ash cenospheres, closed-cell perlite, nitrile rubber powder, and bamboo and wood chips; lightweight aggregates are selected from expanded graphite, hollow glass microspheres, nitrile rubber powder, foam glass cutting waste powder, vanadium-titanium steel slag, and chopped straw; lightweight aggregates are selected from expanded graphite, hollow glass microspheres, aerogel powder, diatomaceous earth, chopped straw, and expanded perlite.

[0020] Furthermore, the bulk density of the hollow glass microspheres is 0.15-0.3 g / cm³. 3 The thermal conductivity is 0.03-0.05 W / (m·K); the bulk density of the aerogel powder is ≤0.1 g / cm³. 3 Thermal conductivity ≤ 0.02 W / (m·K), specific surface area ≥ 600 m² 2 / g; the bulk density of the fly ash cenospheres is 0.4-0.6 g / cm³. 3 The thermal conductivity of the expanded graphite is 0.06-0.10 W / (m·K), and the expansion ratio is 200 times.

[0021] For example, the hollow glass microspheres are 3M VS5500 hollow glass microspheres.

[0022] Further, the expanded graphite has a mesh size of 30-50 mesh; the hollow glass microspheres have a particle size of 40-60 μm; the nitrile rubber powder has a mesh size > 300 mesh; the fly ash cenospheres have a mesh size of 40-60 mesh; the foam glass cutting waste powder has a mesh size of 100 mesh; the pre-de-oiled rapeseed has a particle size of 2-3 mm; the expanded vermiculite has a particle size of 2-5 mm; the lightweight ceramsite powder has a mesh size of 100 mesh; the closed-cell perlite has a mesh size of 100-120 mesh; the bamboo and wood chips have a mesh size of 100-150 mesh; the vanadium-titanium steel slag has a mesh size of 80 mesh; the chopped straw has a particle size of 3 mm; the diatomaceous earth has a mesh size of 200 mesh; and the expanded perlite has a mesh size of 80-120 mesh.

[0023] Furthermore, the light calcium carbonate has a mesh size of 1250 and a whiteness of 95%; the dihydrate gypsum has a mesh size of 80; the bentonite has a mesh size of 200; the lithium slag has a mesh size of 80; the talc has a mesh size of 400; the desulfurized gypsum has a mesh size of 80; and the silica has a mesh size of 800.

[0024] Further, the silicate cement is PO42.5 silicate cement or PO52.5 silicate cement; the early-strength sulfoaluminate cement is grade 42.5 early-strength sulfoaluminate cement; the mineral powder is grade S95 mineral powder; and the silica sol has a solid content of 30%.

[0025] Further, the silane coupling agent is selected from one of γ-glycidoxypropyltrimethoxysilane (KH560), 3-(isobutenoyloxy)propyltrimethoxysilane (KH570), methyltrimethoxysilane (MTMS), and γ-aminopropyltriethoxysilane (KH550); the lithium salt is selected from one of lithium carbonate, lithium chloride, and lithium sulfate; the water-reducing agent is selected from one of polycarboxylate water-reducing agent, naphthalene-based water-reducing agent, or aliphatic water-reducing agent; and the chopped straw is selected from chopped reed stalks (3mm) or chopped wheat straw (5-7mm).

[0026] Further, the concentration of the silane coupling agent isopropanol or anhydrous ethanol solution is 1.5-2 wt%, the concentration of the sodium methylsilicate aqueous solution is 5 wt%, the concentration of the polyamide resin xylene solution is 5 wt%, the concentration of the chloroprene rubber latex aqueous solution is 10 wt%, the concentration of the styrene-acrylic latex aqueous solution is 5 wt%, the concentration of the fluorocarbon latex acetone or toluene solution is 4 wt%, and the concentration of the silicone-acrylic latex anhydrous ethanol solution is 4 wt%.

[0027] Further, by weight, the amount of the lightweight aggregate is 74-81 parts, the amount of the lightweight filler is 27-33 parts, the amount of the cementitious material is 80-84 parts, the amount of the surface treatment agent is 11 parts, the amount of the admixture is 3.2-4.75 parts, and the amount of water is 22-26 parts.

[0028] The principle of this invention: This invention achieves multiple superior properties of composite materials through scientific raw material selection, precise surface modification treatment, and optimized preparation process.

[0029] I. Achieving Waterproof and Oil-Resistant Properties

[0030] Surface modification: Lightweight aggregates are surface-treated with silane coupling agents such as KH560 and KH570. Alkoxy groups are hydrolyzed to form silanol groups, which then condense with hydroxyl groups on the aggregate surface, constructing an organic-inorganic hybrid hydrophobic layer and reducing surface energy (contact angle increased to over 90°). Simultaneously, fluorocarbon emulsions or sodium methylsilicate are incorporated into the cementitious material to form a double hydrophobic barrier, hindering the penetration of water and oil. The silane coupling agents also improve the interfacial bonding between the aggregate and the cementitious material, reducing interfacial microcracks and preventing liquid penetration due to interfacial defects, further enhancing waterproof and oil-resistant properties.

[0031] Reduce porosity: Apply the modified Andreasen-Andersen (MAA) model to rationally configure the particle size of each material, so that the system reaches the most compact packing state. Through the hydration reaction of cementitious materials (silicate cement, sulfoaluminate cement) with mineral powder and silica sol, high-density hydration products (CSH gel, ettringite, etc.) are generated to fill the gaps between aggregates. Combined with polycarboxylate superplasticizer to optimize particle size distribution, reduce porosity (total porosity controlled below 25%) and reduce the adsorption channels of water and oil.

[0032] II. Realization of Chemical Corrosion Resistance

[0033] Surface-resistant film: A stable siloxane film will form on the surface of aggregates treated with KH560 / KH570. This film has excellent chemical stability and can resist the erosion of media such as acids, alkalis and salts. The fluorocarbon emulsion modification layer further enhances the resistance to organic solvents.

[0034] To improve density: PO42.5 / 52.5 silicate cement and early-strength sulfoaluminate cement are blended together, along with active admixtures such as S95 grade mineral powder and blast furnace water-quenched slag. Through secondary hydration reaction, more CSH gel and hydrated calcium aluminate are generated, which improves the density of the matrix (porosity ≤20%) and reduces the intrusion path of corrosive media.

[0035] Impermeability optimization: Adding organosilicon defoamer eliminates air bubbles in the slurry and reduces interconnected porosity; moderate expansion (expansion rate 0.02-0.05%) is generated by sulfate expansion agent to compensate for shrinkage and fill microcracks, further improving the material's impermeability and slowing down the penetration rate of corrosive media.

[0036] III. Achieving low thermal conductivity, lightweight design, and sound absorption / noise reduction:

[0037] 1. Low Thermal Conductivity: Porous Structure Design: Lightweight aggregates such as hollow glass microspheres (thermal conductivity 0.03-0.05 W / (m·K)), expanded graphite (thermal conductivity 0.06-0.10 W / (m·K)), and aerogel powder (thermal conductivity ≤0.02 W / (m·K)) are introduced with a large number of closed pores (pore size 5-50 μm) through porous aggregates such as expanded perlite and fly ash cenospheres. The thermal conductivity of air within the pores is only 0.026 W / (m·K), which can significantly reduce the overall thermal conductivity. At the same time, the porosity is controlled at 30-45% to avoid the strength reduction caused by excessive porosity. The aggregates treated with silane coupling agents form a clear interface with the cementitious matrix, increasing the interfacial resistance to heat flow transfer and further inhibiting heat conduction, so that the thermal conductivity of the multifunctional composite material is stabilized at 0.05-0.07 W / (m·K).

[0038] 2. Lightweight: Low-density aggregates are selected, and hollow glass microspheres (bulk density 0.15-0.3 g / cm³) are used.3 Aerogel powder (bulk density ≤ 0.1 g / cm³) 3 ), fly ash cenospheres (bulk density 0.4-0.6 g / cm³) 3 Lightweight aggregates, such as crushed stone and river sand, have a density only 1 / 5 to 1 / 10 that of traditional sand and gravel, significantly reducing the overall density of multifunctional composite materials. The total content of lightweight aggregates is controlled at 74-81 parts, replacing traditional high-density aggregates (such as crushed stone and river sand). While ensuring strength (compressive strength ≥10MPa), the bulk density of the material is adjusted to 0.5-0.78 g / cm³ depending on the content. 3 (Complies with the lightweight requirements of GB / T11968-2006).

[0039] 3. Sound absorption and noise reduction:

[0040] Porous sound-absorbing structure: Aggregates such as expanded perlite, diatomaceous earth, and chopped straw have a large number of open pores (pore size of 10-100μm). After sound waves enter the pores, they are converted into heat energy due to air viscosity resistance and pore wall friction, thus achieving sound energy absorption.

[0041] Multi-level pore synergy: By compounding 4-5 kinds of lightweight aggregates with different particle sizes (30-120 mesh), a multi-level pore structure is constructed, which can effectively absorb sound waves of different frequencies (250-2000Hz), improve broadband sound absorption performance, and make the noise reduction coefficient (NRC) reach 0.45-0.60.

[0042] Elastic sound absorption mechanism: Elastic aggregates such as nitrile rubber powder can consume sound energy through elastic deformation, which works synergistically with porous sound absorption to further improve the sound absorption and noise reduction effect.

[0043] IV. Achievement of Flame Retardancy and High Temperature Adaptability

[0044] 1. Achievement of flame retardant properties:

[0045] The core barrier function of flame-retardant aggregates: Using inorganic aggregates such as expanded graphite, early-strength sulfoaluminate cement, blast furnace slag, foam glass cutting waste, and aerogel as the core, a dual defense line of physical barrier and thermal inhibition is constructed: Expanded graphite (30-50 mesh, expansion ratio of 200 times) expands rapidly at temperatures ≥200℃, forming a loose and porous carbonaceous insulating layer that blocks heat transfer and contact with oxygen; ettringite (3CaO·Al2O3·3CaSO4·32H2O) generated by the hydration of early-strength sulfoaluminate cement (10-15 parts) expands at temperatures ≤8℃. It maintains its crystal structure at 00℃ and releases water of crystallization upon heating (complete dehydration at 200-350℃). Each gram of water of crystallization absorbs approximately 2.26 kJ of heat, lowering the internal temperature of the material and delaying the pyrolysis of organic components (such as nitrile rubber powder). Blast furnace water-quenched slag (10 parts, softening temperature ≥1200℃) generates more CSH gel through secondary hydration, resulting in a dense matrix structure (porosity ≤20%) and reducing the escape of combustible gases. Foam glass cutting waste (100 mesh, 18-20 parts) and aerogel powder (specific surface area ≥600 m²) 2 / g (dosage of 10-12 parts) are all inorganic non-combustible materials. The former blocks heat convection by closing pores, while the latter constructs a thermal barrier with a low thermal conductivity of ≤0.02W / (m·k). Together with expanded graphite, they form a "surface-interior" double-layer thermal insulation structure to block the spread of flames.

[0046] Enhanced protection of the flame-retardant interface: A high-temperature inert interface is constructed on the aggregate surface using surface treatment agents such as silane coupling agents (KH570, KH560, MTMS), fluorocarbon emulsions, and polyamide resins. KH570 (2wt% isopropanol solution) hydrolyzes and condenses to form a hybrid layer containing Si-O-Si bonds (thermal decomposition temperature ≥450℃), which encapsulates aggregates such as hollow glass microspheres and expanded perlite, inhibiting particle fragmentation at high temperatures. MTMS (1.5wt% ethanol solution) is converted into a dense SiO2 film at high temperatures, which fuses with the glass phase formed by sodium methylsilicate, filling the microcracks at the interface. Fluorocarbon emulsion (4wt% acetone / toluene solution) and polyamide resin (5wt% xylene solution) form an inert protective layer on the aggregate surface, delaying thermal decomposition and reducing contact between oxygen and internal components.

[0047] Precise control of components: Strictly control the content of organic components (nitrile rubber powder, chopped straw, etc., ≤10 parts) to avoid the accumulation of flammable components; inorganic aggregates are the main component (total content ≥50%), combined with dihydrate gypsum (80 mesh, 6-8 parts) - its heat absorption during dehydration (150-650℃) and the generated anhydrite (CaSO4) reacts with Al2O3 to form high-temperature resistant calcium aluminum feldspar (melting point ≥1590℃); supplemented with lithium sulfate and sulfate expansion agent, the former promotes the formation of lithium aluminum silicate (melting point ≥1530℃) to fill the pores, and the latter compensates for shrinkage and compacts the matrix, ultimately making the material oxygen index ≥30% (oxygen index as high as 33%-34%), meeting the GB8624-2012 B1 flame retardant level.

[0048] 2. Achieving high-temperature adaptability: High-temperature stability design of inorganic systems

[0049] Construction of high-temperature resistant matrix: The matrix is ​​composed of inorganic cementitious materials such as silicate cement (PO42.5 / 52.5), early-strength sulfoaluminate cement, mineral powder (S95 grade), and blast furnace water-quenched slag. Its hydration products (CSH gel, ettringite, and hydrated calcium aluminate) have excellent high-temperature stability: ettringite does not decompose at ≤800℃, and the softening temperature of blast furnace water-quenched slag is ≥1200℃. Even in short-term high-temperature environments below 800℃, the matrix can still maintain structural integrity, avoiding the high-temperature failure problem of organic materials (such as epoxy resin cross-linking network destruction above 80℃ and polyurethane softening at 60℃).

[0050] Sustained stability of performance at high temperatures: On the one hand, inorganic aggregates (such as foam glass cutting waste and aerogel powder) have no risk of pyrolysis or combustion at high temperatures, and their closed pore structure can block heat transfer for a long time, keeping the thermal conductivity of the material stable at 0.05-0.07 W / (m·k) without significant fluctuations with increasing temperature; on the other hand, active admixtures (mineral powder and blast furnace water-quenched slag) can continuously undergo secondary hydration at high temperatures, further densifying the matrix, and maintaining a 28-day compressive strength of 3.4-4.2 MPa, avoiding the mechanical property degradation caused by long-term high temperatures (such as the tensile strength of organic materials decreasing by more than 50% at 120℃).

[0051] The present invention also provides a method for preparing the above-mentioned multifunctional composite material, comprising the following steps:

[0052] Weigh each ingredient accurately according to the weight proportions;

[0053] Some lightweight aggregates were pretreated with a surface treatment agent;

[0054] Pretreated lightweight aggregate, untreated lightweight aggregate, and lightweight filler are mixed and dry-mixed to obtain material A.

[0055] Dissolve the additives other than water-reducing agent and silicone defoamer in water, add the gelling material, stir, then add water-reducing agent and silicone defoamer, stir again to obtain material B;

[0056] Material A is added to material B, stirred, molded, and cured to obtain the multifunctional composite material.

[0057] The present invention also provides an application of the above-mentioned multifunctional composite material in the preparation of materials that simultaneously meet the requirements of corrosion resistance, buoyancy support, lightweight insulation and safety protection.

[0058] Compared with the prior art, the present invention has the following advantages and technical effects:

[0059] The multifunctional composite material provided by this invention is suitable for industrial scenarios that require simultaneous performance in terms of corrosion resistance, buoyancy support, lightweight insulation, and safety protection. These include, but are not limited to, passive energy absorption protection, petrochemical storage and transportation facilities, deep-sea exploration equipment, structural filling engineering in flammable and explosive environments, and acoustic noise reduction engineering. The multifunctional composite material provided by this invention is a material with multi-environmental adaptability, particularly suitable for composite functional material systems that combine waterproof and oil-resistant properties, chemical corrosion resistance, low thermal conductivity, flame retardancy and high-temperature adaptability, sound absorption and noise reduction, and lightweight structural characteristics. Attached Figure Description

[0060] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0061] Figure 1 SEM image of the multifunctional composite material prepared in Example 1;

[0062] Figure 2 SEM image of the multifunctional composite material prepared in Example 2;

[0063] Figure 3 SEM image of the multifunctional composite material prepared in Example 3;

[0064] Figure 4 SEM image of the multifunctional composite material prepared in Example 4;

[0065] Figure 5 This is a SEM image of the multifunctional composite material prepared in Example 5. Detailed Implementation

[0066] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0067] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0068] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0069] Vermiculite is a natural mineral with a raw ore density of approximately 2.4-2.7 g / cm³. 3 It is generally not used directly. In factories, when heated to 800-1000℃, the interlayer moisture vaporizes, causing the volume to expand 5-20 times, forming porous, lightweight "expanded vermiculite." After expansion, its density decreases significantly (to 0.06-0.2 g / cm³). 3 ).

[0070] In the following embodiments of the present invention, the hollow glass microspheres are 3M VS5500 hollow glass microspheres.

[0071] In embodiments of the present invention, by weight, the following components are used: 14-17 parts of expanded graphite, 10-18 parts of hollow glass microspheres, 6-8 parts of nitrile rubber powder, 14-15 parts of fly ash cenospheres, 18-20 parts of foam glass cutting waste powder, 8 parts of pre-de-oiled rapeseed, 10-12 parts of aerogel powder, 14 parts of expanded vermiculite, 10 parts of lightweight ceramsite powder, 9 parts of bamboo and wood chips, 16 parts of closed-cell perlite, 12 parts of expanded perlite, 18 parts of diatomaceous earth, and 8-15 parts of chopped straw.

[0072] In embodiments of the present invention, by weight, the amount of light calcium carbonate is 10-12 parts, the amount of gypsum dihydrate is 6-8 parts, the amount of bentonite is 5-7 parts, the amount of lithium slag is 6 parts, the amount of silica is 6 parts, and the amount of desulfurized gypsum is 6 parts.

[0073] In the embodiments of the present invention, the amount of silicate cement is 40-48 parts, the amount of early-strength sulfoaluminate cement is 10-15 parts, the amount of mineral powder is 8-15 parts, the amount of blast furnace water-quenched slag cement is 10 parts, the amount of silica sol is 5-6 parts, the amount of alkali-activated cement is 7-8 parts, the amount of blast furnace water-quenched slag is 5-8 parts, the amount of magnesium oxychloride cement is 8 parts, and the amount of magnesium phosphate cement is 8 parts.

[0074] In embodiments of the present invention, by weight, the following components are used: 3 parts of KH560 isopropanol solution, 3 parts of sodium methylsilicate aqueous solution, 2 parts of fluorocarbon emulsion acetone solution, 2 parts of polyamide resin xylene solution, 1 part of chloroprene rubber emulsion aqueous solution, 1 part of silicone acrylic emulsion anhydrous ethanol solution, 2 parts of MTMS anhydrous ethanol solution, 3 parts of KH570 isopropanol solution, 2 parts of KH550 anhydrous ethanol solution, 3 parts of fluorocarbon emulsion toluene solution, and 2 parts of styrene-acrylic emulsion aqueous solution.

[0075] For example, the preparation method of KH560 isopropanol solution is as follows: KH560 is added to isopropanol and stirred evenly to obtain a solution with a concentration of 2 wt%; the preparation method of sodium methylsilicate aqueous solution is as follows: sodium methylsilicate is added to water and stirred evenly to obtain a solution with a concentration of 5 wt%; the preparation method of fluorocarbon emulsion acetone solution is as follows: fluorocarbon emulsion is added to acetone and stirred evenly to obtain a solution with a concentration of 4 wt%; the preparation method of polyamide resin xylene solution is as follows: polyamide resin is added to xylene and stirred evenly to obtain a solution with a concentration of 5 wt%; the preparation method of chloroprene rubber emulsion aqueous solution is as follows: chloroprene rubber emulsion is added to water... The following methods were used to prepare solutions: 10% concentration of silicone-acrylic emulsion in anhydrous ethanol was obtained by adding silicone-acrylic emulsion to anhydrous ethanol and stirring until homogeneous; 1.5 wt% concentration of MTMS in anhydrous ethanol was obtained by adding MTMS to anhydrous ethanol and stirring until homogeneous; 2 wt% concentration of KH570 in isopropanol was obtained by adding KH570 to isopropanol and stirring until homogeneous; and 2 wt% concentration of KH550 in anhydrous ethanol was obtained by adding KH550 to anhydrous ethanol and stirring until homogeneous.

[0076] In embodiments of the present invention, by weight, the water-reducing agent is 0.3-0.5 parts, the silicone defoamer is 0.2 parts, the sulfate expanding agent is 2 parts, the lithium salt is 0.4-0.7 parts, the hydrated calcium silicate whiskers are 3 parts, and the sodium aluminate is 2 parts.

[0077] In the following embodiments of the present invention, the sulfate expanding agent is ZY-1100A purchased from Shanghai Zengye Industrial Co., Ltd.; the organosilicon defoamer is ZY-803 purchased from Shanghai Zengye Industrial Co., Ltd.; the polycarboxylate superplasticizer is 1029 purchased from Suzhou Fuke Technology Co., Ltd.; the naphthalene-based superplasticizer is FDN-C purchased from Shandong Wanshan Chemical Co., Ltd.; and the aliphatic superplasticizer is SAF-L1 purchased from Laiwu Yanhui Building Materials Co., Ltd.

[0078] In an embodiment of the present invention, the dry mixing speed is 200 rpm and the time is 8 minutes to ensure that the lightweight aggregate and lightweight filler are evenly dispersed and to avoid local density differences.

[0079] Embodiments of the present invention also provide an application of the above-mentioned multifunctional composite material in the preparation of materials that simultaneously meet the requirements of corrosion resistance, buoyancy support, lightweight insulation and safety protection.

[0080] In some embodiments of the present invention, the nitrile rubber powder and expanded graphite in the lightweight aggregate are not pretreated.

[0081] In embodiments of the present invention, KH570 isopropanol solution is used to pretreat aerogel powder or diatomaceous earth. Through chemical bonding, new organic functional groups are introduced onto the material surface, thereby directionally regulating its hydrophobic and oleophobic (dual-hydrophobic) properties and enhancing its compatibility and binding force with subsequent materials. Sodium methylsilicate aqueous solution is used to pretreat expanded vermiculite, foam glass cutting waste, hollow glass microspheres, or closed-cell perlite. Closed-cell perlite prevents moisture absorption in underground wells. MTMS anhydrous ethanol solution or chloroprene rubber latex aqueous solution is used to pretreat hollow glass microspheres. Alternatively, styrene-acrylic latex aqueous solution can be used for pretreating hollow glass microspheres. The methoxy group at one end of MTMS hydrolyzes to generate silanol groups, which then bind to the hollow glass microspheres. The silanol groups on the surface of hollow glass microspheres undergo dehydration condensation to form strong Si-O-Si covalent bonds; the organic groups (methyl groups attached to silicon) at the other end of the MTMS molecule align outwards, changing the surface of the hollow glass microspheres from hydrophilic to hydrophobic, and enabling good compatibility with organic polymers; the polymer chains of chloroprene rubber latex physically adsorb and encapsulate the surface of the hollow glass microspheres, and after water evaporation, a continuous and dense polymer elastic film is formed. Utilizing the low-density characteristics of hollow glass microspheres, they can be filled into polymer matrices such as rubber, significantly reducing the density and cost of multifunctional composite materials; pretreatment of nitrile rubber powder, expanded graphite, aerogel powder, or vanadium-titanium steel slag with fluorocarbon emulsion acetone solution constructs oil-resistant surfaces. The process involves: pre-treating pre-degreased rapeseed, hollow glass microspheres, or expanded graphite with a polyamide resin xylene solution to seal the pores and prevent oil penetration; pre-treating fly ash cenospheres or foam glass cutting waste powder with a KH560 isopropanol solution. Fly ash cenospheres have low thermal conductivity, and pre-treating them with KH560 reduces their surface energy, decreases particle agglomeration, and promotes more uniform powder distribution within the organic matrix, improving material flowability. This process also forms "molecular bridges" between the inorganic powder and organic polymer, significantly enhancing the material's mechanical strength, water resistance, and moisture resistance; and finally, using a silicone-acrylic emulsion. Pretreatment of lightweight ceramsite powder with anhydrous ethanol solution allows the silicone-acrylic emulsion to form an organic polymer film on the surface of the powder, effectively sealing surface pores. This film significantly reduces the oil and water absorption rates of the lightweight ceramsite powder and decreases internal adsorption, which is crucial for the moisture-proofing, waterproofing, and stability maintenance of porous lightweight ceramsite powder. It also improves the crushing and abrasion values ​​of the powder, enhancing its mechanical strength and making it less prone to breakage in mixtures or under stress. Pretreatment of bamboo and wood chips with KH550 anhydrous ethanol solution improves the compatibility and interfacial bonding between the bamboo and wood chips and subsequent materials, thereby enhancing the overall performance of multifunctional composite materials (such as mechanical strength, water resistance, and durability).Pretreatment of chopped straw with either a chloroprene rubber latex aqueous solution or a styrene-acrylic latex aqueous solution results in the following properties: The chloroprene rubber latex aqueous solution forms a tough, highly elastic polymer film on the surface of the chopped straw, giving the material excellent adhesion, oil resistance, and aging resistance; the styrene-acrylic latex forms a dense, hard polymer coating on the surface of the chopped straw, giving the material good water resistance, abrasion resistance, scrub resistance, and alkali resistance.

[0082] In an embodiment of the present invention, the composition of the blast furnace water-quenched slag, by mass percentage, is as follows: (calcium oxide (CaO) 32.907±0.043%, silicon dioxide (SiO2) 22.931±0.064%, titanium dioxide (TiO2) 20.273±0.042%, aluminum oxide (Al2O3) 12.151±0.068%, magnesium oxide (MgO) 7.415±0.083%), ferric oxide (Fe2O3) 1%. 695±0.007%, sulfur trioxide (SO3) 1.588±0.027%, manganese oxide (MnO) 0.618±0.004%, potassium oxide (K2O) 0.273±0.004%, strontium oxide (SrO) 0.075%, zirconium dioxide (ZrO2) 0.037%, barium oxide (BaO) 0.031±0.005%, yttrium trioxide (Y2O3) 0.006%, niobium oxide (NbO) 0.002%.

[0083] In the embodiments of the present invention, the composition of vanadium-titanium steel slag by mass percentage is as follows: SiO2 37.898±0.099%, CaO2 0.054±0.047%, Fe2O3 18.621±0.025%, Al2O3 12.113±0.076%, MgO 5.120±0.170%, TiO2 4.227±0.020%, SO3 1.450±0.106%, MnO 0.259±0.006%, SrO 0.141±0.001%, K2O 0.070±0.008%, chromium trioxide (Cr2O3) 0.029±0.005%, and zinc oxide (ZnO) 0.017±0.002%.

[0084] In the embodiments of the present invention, the composition of the lithium slag, by mass percentage, is as follows: SiO2 53.244±0.081%, Al2O3 20.902±0.067%, SO3 14.313±0.106%, CaO 8.259±0.020%, Fe2O3 1.657±0.005%, K2O 0.781±0.007%, MnO 0.172±0.002%, phosphorus pentoxide (P2O5) 0.164±0.009%, TiO2 0.119±0.004%, rubidium oxide (Rb2O) 0.096%, sodium oxide (Na2O) 0.069±0.008%, tin dioxide (SnO2) 0.060±0.002%, MgO 0.045±0.021%, Cr2O3 0.038±0.002%, Gallium trioxide (Ga2O3) 0.015±0.001%, ZnO 0.014±0.001%, NbO 0.014%, Arsenic trioxide (As2O3) 0.012±0.002%, Copper oxide (CuO) 0.009±0.001%, SrO 0.008%, Gold oxide (Au2O) 0.005±0.001%, Nickel oxide (NiO) 0.003±0.001%.

[0085] A smoke density rating (SDR) of 80 indicates that the material produces 80% of its maximum possible smoke during a 0-4 minute combustion test. The higher the value, the greater the amount of smoke produced when the material burns.

[0086] Fly ash cenospheres are unique lightweight hollow glass microspheres found in fly ash from coal-fired power plants, named for their ability to float on water. The formation of fly ash cenospheres originates from the high-temperature combustion process within the boiler of a coal-fired power plant: Melting stage: The clay components in the coal (oxides of silicon, aluminum, iron, etc.) melt at temperatures above 1300℃, forming a porous symbiosis of quartz glass and mullite; Spheroidizing stage: Molten droplets rotate at high speed under the influence of turbulent hot air within the furnace, forming perfectly round silicon-aluminum spheres; Hollowing stage: Gases produced during combustion (N2, H2, CO2) expand within the molten spheres, forming a hollow structure under surface tension; Cooling and solidification: After entering the flue, the spheres rapidly cool and harden into high-vacuum glassy hollow microspheres. Fly ash cenospheres are grayish-white or silvery-gray, with a smooth and closed surface and a vitreous luster. The main components are SiO2 (50%–65%) and Al2O3 (25%–35%), with small amounts of Fe2O3, CaO, MgO, etc. The mineral phase is mainly glassy, ​​and the crystalline phases are mullite and quartz.

[0087] Blast furnace water-quenched slag cement is a hydraulic cementitious material made by co-grinding silicate cement clinker, granulated blast furnace slag, and gypsum. The granulated blast furnace slag content is 20%-70%. It possesses characteristics such as low heat of hydration, good corrosion resistance, high later-stage strength, and strong heat resistance, but suffers from low early-stage strength and poor frost resistance. 1. To improve early-stage strength, this invention employs lithium salts, early-strength crystal nucleation, and alkali activation to promote the formation of hydration products. By increasing the nucleation sites of CSH gel, the nucleation barrier potential is reduced, and the induction period is shortened, thereby improving early-stage hydration strength. 2. For solutions to frost resistance, one approach is to use a combination of one or more water-reducing agents to reduce the amount of mixing water, fundamentally reducing the destructive force. Another approach is to optimize the pore structure and improve density, based on the extended application of the MAA (Most Closest Packing) theory in materials of different particle sizes, and to rationally combine the proportions of each component material.

[0088] Sulfate expansive agents are admixtures that improve concrete performance by causing volume expansion through a chemical reaction. Their core function is to compensate for shrinkage and enhance crack resistance and impermeability; however, strict control of usage conditions is necessary to avoid negative effects. In this invention, the negative effects are avoided by controlling the dosage of the sulfate expansive agent.

[0089] Unless otherwise specified, the room temperature in this invention is 25±2℃.

[0090] Unless otherwise specified, "parts" in this invention refers to parts by weight.

[0091] All raw materials used in the embodiments of this invention were purchased commercially. For example, the foam glass cutting waste powder was from Baofeng Shengnuo Ceramics Factory; the pre-de-oiled rapeseed was purchased from Chengdu Fangleran Agricultural Development Co., Ltd.; the light calcium carbonate was purchased from Jiangxi Guangyuan Chemical Co., Ltd., model HX-816; the fluorocarbon emulsion was purchased from Yoshida Chemical, model F13-0801; the aerogel powder was LBF aerogel powder purchased from Langmiao Environmental Protection Technology (Tianjin) Co., Ltd.; the light ceramsite powder was purchased from Sichuan Henglide New Building Materials Co., Ltd., grade 300 (3-5mm); the hydrated calcium silicate whiskers were purchased from Nanjing Xinyi Synthetic New Materials Co., Ltd., model S7044; the closed-cell perlite was purchased from Xinyang Castel Materials Technology Co., Ltd., with a particle size of 90-120 mesh; and the expanded perlite was purchased from Xinyang Castel Materials Technology Co., Ltd., with a particle size of 70-90 mesh.

[0092] It should be noted that any aspects not described in detail in this invention are conventional practices in the field and are not the focus of this invention.

[0093] The technical solution of the present invention will be further illustrated by the following embodiments.

[0094] Example 1

[0095] This embodiment provides a multifunctional composite material, the raw material composition of which is as follows, by weight parts:

[0096] Lightweight aggregates: 16 parts expanded graphite (30-50 mesh, expansion ratio of 200 times), 13 parts 3M VS5500 hollow glass microspheres (40-60μm), 7 parts nitrile rubber powder (>300 mesh (corresponding to a particle size of about 48μm or less), crushed by liquid nitrogen), 14 parts fly ash cenospheres (40-60 mesh), 18 parts foam glass cutting waste powder (100 mesh), and 8 parts pre-de-oiled rapeseed (2-3mm);

[0097] Lightweight filler: 11 parts of lightweight calcium carbonate (1250 mesh, whiteness 95%), 7 parts of gypsum dihydrate (80 mesh), 6 parts of bentonite (200 mesh), and 6 parts of lithium slag (80 mesh);

[0098] Cementing materials: 42 parts of PO42.5 silicate cement, 14 parts of early-strength sulfoaluminate cement (42.5 grade), 10 parts of mineral powder (S95 grade), 10 parts of blast furnace water-quenched slag cement, and 5 parts of silica sol (30% solid content).

[0099] Surface treatment agents: 3 parts of KH560 (γ-glycidoxypropyltrimethoxysilane) isopropanol solution (KH560 is added to isopropanol and stirred evenly to obtain a 2wt% solution), 3 parts of sodium methylsilicate aqueous solution (sodium methylsilicate is added to water and stirred evenly to obtain a 5wt% solution), 2 parts of fluorocarbon emulsion acetone solution (fluorocarbon emulsion is added to acetone and stirred evenly to obtain a 4wt% solution), 2 parts of polyamide resin xylene solution (polyamide resin is added to xylene and stirred evenly to obtain a 5wt% solution), and 1 part of chloroprene rubber emulsion aqueous solution (chloroprene rubber emulsion is added to water and stirred evenly to obtain a 10% solution).

[0100] Admixtures: 0.4 parts polycarboxylate superplasticizer (40% solid content), 0.2 parts silicone defoamer (10% solid content), 2 parts sulfate expanding agent, and 0.6 parts lithium sulfate. The polycarboxylate superplasticizer is 1029 from Suzhou Fuke Technology Co., Ltd. (hereinafter the same), the silicone defoamer is ZY-803 from Shanghai Zengye Industrial Co., Ltd. (hereinafter the same), and the sulfate expanding agent is ZY-1100A from Shanghai Zengye Industrial Co., Ltd. (hereinafter the same).

[0101] The preparation method of the above-mentioned multifunctional composite material includes the following steps:

[0102] Weigh each ingredient accurately according to the weight proportions;

[0103] Lightweight aggregate pretreatment: Expanded graphite was mixed with fluorocarbon emulsion acetone solution, stirred at 200 rpm for 25 minutes, and dried at 60°C for 5 hours (to construct an oil-resistant surface layer); pre-degreased rapeseed was mixed with polyamide resin xylene solution, soaked for 30 minutes, and dried at 40°C for 8 hours (to seal rapeseed pores and prevent oil penetration); fly ash cenospheres were mixed with KH560 isopropanol solution, stirred at 250 rpm for 30 minutes, and dried at 50°C for 6 hours; foam glass cutting waste was mixed with sodium methylsilicate aqueous solution, stirred at 200 rpm for 25 minutes, and dried at 60°C for 6 hours; 3M VS5500 hollow glass microspheres were mixed with chloroprene rubber emulsion aqueous solution, stirred at 200 rpm for 25 minutes, and dried at 50°C for 6 hours.

[0104] Preparation of Material A: Add the pretreated lightweight aggregate, nitrile rubber powder and lightweight filler to a planetary mixer and dry mix at 200 rpm for 8 minutes to obtain a uniform Material A (ensure that the aggregate and filler are evenly dispersed to avoid local density differences).

[0105] Preparation of Material B: Dissolve lithium sulfate and sulfate expansion agent in 25 parts (by weight, the same below) of water, then add PO42.5 silicate cement, early strength sulfoaluminate cement, mineral powder, blast furnace water-quenched slag cement and silica sol, stir at 250 rpm for 6 minutes, add polycarboxylate superplasticizer and organosilicon defoamer and continue stirring for 2 minutes to obtain Material B;

[0106] Composite molding: Add material A to material B, stir at 250 rpm for 12 minutes, pour into a 300mm×300mm×50mm mold, compact under 2.5MPa pressure for 10 minutes, and cure at room temperature (25±2℃) for 28 days to obtain a multifunctional composite material.

[0107] SEM image of the multifunctional composite material prepared in Example 1 is shown below. Figure 1 As shown, the multifunctional composite material prepared in this embodiment exhibits a dense particle packing morphology with tight bonding between particles and no obvious interconnected pores, which can significantly reduce the permeation channels of oil / corrosive media. At the same time, it has small closed pores ranging from hundreds of nanometers to 1 μm (which matches the macroscopic feature of "5-50 μm closed pores" introduced by lightweight aggregates through porous aggregates, this is a local detail). The absence of open channels can prevent the diffusion of media in the pores, and a uniform coating structure can be seen on the particle surface, corresponding to an "organic-inorganic hybrid hydrophobic layer". These microstructures together endow the material with excellent anti-adhesion and corrosion resistance, which is precisely adapted to the application scenarios of oil and gas field anti-corrosion lining and chemical storage tank protection.

[0108] The performance indicators of the multifunctional composite material prepared in this embodiment are as follows:

[0109] Room temperature mechanical properties: 28-day room temperature compressive strength is 13.0 MPa, tensile strength is 1.8 MPa, elongation at break is 4.0%, and interlaminar shear strength is 1.0 MPa; Chemical corrosion resistance: After immersion in 5 wt% hydrochloric acid solution for 30 days, there is no obvious corrosion or blistering on the surface, and the retention rates of compressive strength, tensile strength, elongation at break, and interlaminar shear strength are 76.9%, 72.2%, 67.5%, and 75.0%, respectively. After immersion in 5 wt% sodium hydroxide solution for 30 days, there is no cracking or powdering on the surface, and the retention rates of the above four strengths are 86.2%, 83.3%, 77.5%, and 80.0%, respectively; Waterproofing, oil resistance, and chemical resistance. Corrosion performance: The material's volumetric water absorption rate is 7.0%; after 90 days of immersion in 0# diesel oil, the interlaminar shear strength retention rate is 78%; after 180 days of immersion in 10% crude oil (containing aromatic components), the compressive strength retention rate is 82%, and there are no blistering, delamination, or swelling phenomena on the material surface. Low thermal conductivity: The steady-state thermal conductivity is 0.058 W / (m·K). Flame retardancy: The oxygen index is 33%, and there are no molten drips during vertical combustion (reaching B1 level). High-temperature adaptability: After baking at 80℃ for 72 hours, the compressive strength retention rate is 91%, and there is no cracking or deformation after short-term high-temperature treatment at 100℃. Sound absorption and noise reduction: The sound absorption coefficient in the 500-2000Hz frequency band is 0.32-0.45, and the bulk density is 0.68 g / cm³. 3 Surface density ≤15kg / m³ 2 The multifunctional composite material prepared in this embodiment exhibits excellent performance indicators.

[0110] Based on the above comprehensive performance, the multifunctional composite material of this embodiment can be widely used in the field of oil and gas field surface facilities, as an anti-corrosion lining for oil and gas gathering and transportation pipelines, and as a protective layer for the inner wall of crude oil storage tanks, adapting to the complex corrosive environment of oil fields; in chemical storage and anti-corrosion engineering, it can be used as a partition wall for acid and alkali storage tank areas, and as a floor for chemical workshops, resisting common industrial corrosive media; it is suitable for green buildings and high-rise buildings, as a non-load-bearing partition wall panel to achieve lightweight, heat insulation, flame retardancy and sound absorption and noise reduction functions; it can be applied to cold chain insulation engineering, as a cold storage wall insulation layer to reduce cold loss; it can also be used in the field of rail transit to make subway tunnel sound-absorbing panels, platform sound barriers, etc., to meet the requirements of safe installation and noise reduction.

[0111] The testing methods for the above performance are based on the following standards:

[0112] Room temperature mechanical properties: GB / T50081-2019 "Standard for Test Methods of Physical and Mechanical Properties of Concrete";

[0113] Waterproof and oil-resistant properties: HG / T3830-2017 "Industrial Equipment Anti-corrosion Coatings";

[0114] Chemical corrosion resistance: GB / T50082-2009 "Standard for Test Methods of Long-Term Performance and Durability of Ordinary Concrete";

[0115] Low thermal conductivity: GB / T10294-2008 "Determination of steady-state thermal resistance and related properties of thermal insulation materials - protective hot plate method";

[0116] Flame retardant performance: GB8624-2012 "Classification of Burning Performance of Building Materials and Products";

[0117] High-temperature adaptability: HG / T3830-2017 "Industrial Equipment Anti-corrosion Coatings";

[0118] Sound absorption and noise reduction performance: GB / T20247-2006 "Sound absorption measurement of acoustic reverberation chamber";

[0119] Lightweight structural performance: GB / T11968-2006 "Autoclaved Aerated Concrete Blocks".

[0120] Example 2

[0121] This embodiment provides a multifunctional composite material, the raw material composition of which is as follows, by weight parts:

[0122] Lightweight aggregate: 15 parts expanded graphite (30-50 mesh, expansion ratio 200 times), 18 parts 3M VS5500 hollow glass microspheres (40-60μm), and aerogel powder (specific surface area ≥600m²). 2 12 parts of nitrile rubber powder (>300 mesh, crushed by liquid nitrogen), 6 parts of expanded vermiculite (particle size 2-5 mm), and 10 parts of lightweight ceramsite powder (100 mesh).

[0123] Lightweight filler: 10 parts of lightweight calcium carbonate (1250 mesh, whiteness 95%), 6 parts of gypsum dihydrate (80 mesh), 5 parts of bentonite (200 mesh), and 6 parts of silica (800 mesh);

[0124] Cementing materials: 40 parts of PO52.5 silicate cement, 12 parts of early-strength sulfoaluminate cement (42.5 grade), 15 parts of mineral powder (S95 grade), 8 parts of alkali-activated cement (sodium silicate modulus of 3.2), and 6 parts of silica sol (solid content of 30%).

[0125] Surface treatment agents: 3 parts of KH570 (3-(isobutenoyloxy)propyltrimethoxysilane) isopropanol solution (KH570 is added to isopropanol and stirred evenly to obtain a 2wt% solution), 2 parts of MTMS (methyltrimethoxysilane) anhydrous ethanol solution (MTMS is added to anhydrous ethanol and stirred evenly to obtain a 1.5wt% solution), 3 parts of sodium methylsilicate aqueous solution (sodium methylsilicate is added to water and stirred evenly to obtain a 5wt% solution), 2 parts of fluorocarbon emulsion acetone solution (fluorocarbon emulsion is added to acetone and stirred evenly to obtain a 4wt% solution), and 1 part of silicone acrylic emulsion anhydrous ethanol solution (silicone acrylic emulsion is added to anhydrous ethanol and stirred evenly to obtain a 4wt% solution).

[0126] Additives: 0.3 parts polycarboxylate superplasticizer (40% solid content), 0.2 parts silicone defoamer (10% solid content), 0.4 parts lithium carbonate, and 3 parts calcium silicate hydrate whiskers;

[0127] The preparation method of the above-mentioned multifunctional composite material includes the following steps:

[0128] Weigh each ingredient accurately according to the weight proportions;

[0129] Lightweight aggregate pretreatment: Aerogel powder is mixed with KH570 isopropanol solution, ultrasonically dispersed for 20 minutes (to ensure uniform dispersion of aerogel), and dried at 50℃ for 6 hours; expanded vermiculite is mixed with sodium methylsilicate aqueous solution, stirred at 200 rpm for 25 minutes, and dried at 60℃ for 6 hours; 3M VS5500 hollow glass microspheres are mixed with MTMS anhydrous ethanol solution, stirred at 250 rpm for 30 minutes, and dried at 50℃ for 6 hours; nitrile rubber powder is mixed with fluorocarbon emulsion acetone solution, stirred at 200 rpm for 25 minutes, and dried at 50℃ for 6 hours; lightweight ceramsite powder is mixed with silicone acrylic emulsion anhydrous ethanol solution, stirred at 200 rpm for 25 minutes, and dried at 50℃ for 6 hours.

[0130] Preparation of Material A: Add the pretreated lightweight aggregate, expanded graphite, lightweight filler and hydrated calcium silicate whiskers into a mixer and dry mix at 220 rpm for 8 minutes to obtain a uniform Material A (hydrated calcium silicate whiskers and lightweight aggregate synergistically enhance mechanical properties without affecting lightweight).

[0131] Preparation of Material B: Dissolve lithium carbonate in 22 parts of water, then add PO52.5 silicate cement, early-strength sulfoaluminate cement, mineral powder, alkali-activated cement and silica sol, stir at 250 rpm for 5 minutes, add polycarboxylate superplasticizer and organosilicon defoamer and continue stirring for 2 minutes to obtain Material B;

[0132] Composite molding: Add material A to material B, stir at 300 rpm for 5 minutes (to ensure uniformity of the system), pour into a 200mm×200mm×30mm mold, compact under 1.5MPa pressure, and cure at room temperature (25±2℃) for 28 days to obtain a multifunctional composite material.

[0133] SEM image of the multifunctional composite material prepared in Example 2 is shown below. Figure 2 As shown, the aerogel powder clearly exhibits a porous, loose, flocculent morphology with numerous nanoscale micropores. It is also dispersed in the matrix in conjunction with spherical hollow glass microspheres. By relying on its own micropores, it achieves multi-path dissipation of sound waves. Combined with the sound absorption and vibration reduction effect of the open pores, it achieves a broadband sound absorption effect. At the same time, its lightweight and porous characteristics can also reduce the thermal conductivity of the material to improve its thermal insulation performance. Combined with its seawater corrosion resistant structural features, these functions are perfectly suited to the application scenarios of noise reduction and thermal insulation in marine engineering and sound absorption in subway tunnels.

[0134] The performance indicators of the multifunctional composite material prepared in this embodiment are as follows:

[0135] Room temperature mechanical properties: At room temperature, the 28-day compressive strength is 13.8 MPa, the tensile strength is 2.0 MPa, and the elongation at break is 4.2%. Water and oil resistance: After immersion in 3.5 wt% sodium chloride solution for 180 days, the volume water absorption rate is 3.2%. After immersion in machine oil for 72 hours, there is no swelling or discoloration on the surface. Chemical corrosion resistance: After immersion in 3.5 wt% sodium chloride solution for 180 days, the compressive strength retention rate is 85%. After immersion in 10 wt% sodium hydroxide solution for 30 days, the strength retention rate is 78%, and the tensile strength retention rate is 75%, with no cracking or powdering. After immersion in 5 wt% potassium hydroxide solution for 60 days, the compressive strength retention rate is 72%, with no swelling or discoloration on the surface, good structural integrity, and alkaline solution corrosion results meet the requirements of GB / T50082-2009. After immersion in 5 wt% hydrochloric acid solution for 30 days, the compressive strength retention rate is 70%, and the tensile strength retention rate is 68%. The elongation at break is 65% retained, and there are no obvious corrosion pits on the surface. After soaking in 10wt% sulfuric acid solution for 30 days, the compressive strength retention rate is 67%, the tensile strength retention rate is 64%, and the elongation at break retention rate is 62%, with no peeling or delamination. The changes in mechanical properties after acid immersion meet the requirements of GB / T50082-2009. In terms of low thermal conductivity: the steady-state thermal conductivity is 0.054W / (m·k). In terms of flame retardancy: the oxygen index is 32%, the burning length in the horizontal burning test is ≤25mm, and there are no ignition drips. In terms of high temperature adaptability: after baking at 100℃ for 72h, the compressive strength retention rate is 88%, and there is no cracking or delamination after 20 cycles of cold and hot cycling from -20℃ to 100℃. In terms of sound absorption and noise reduction: the sound absorption coefficient in the 250-2000Hz frequency band is 0.42-0.58, and the noise reduction coefficient (NRC) is 0.45. In terms of lightweight structure: the bulk density is 0.52g / cm³.3 Buoyancy reserve ≥48%.

[0136] The core acoustic properties of the multifunctional composite material prepared in this embodiment are as follows: the sound absorption coefficient is 0.42-0.58 in the 250-2000Hz frequency band (covering the main noise frequencies such as human voice and equipment operation), and the noise reduction coefficient (NRC) is 0.45, meeting the requirements for efficient absorption of mid-to-high frequency noise. The sound absorption performance is synergistic with lightweight and flame retardancy, and there is no acoustic attenuation problem after moisture absorption. The long-term sound absorption coefficient stability is ≥90% (tested after soaking in a 3.5wt% sodium chloride solution for 180 days).

[0137] The multifunctional composite material prepared in this embodiment can be used in the following scenarios:

[0138] Acoustic optimization scenarios: noise reduction lining panels for subway / high-speed rail tunnels, sound-absorbing ceilings for airport terminals, noise reduction partitions for industrial plants (such as fan rooms and air compressor stations), and acoustic decorative panels for conference rooms / concert halls.

[0139] Marine engineering applications: noise reduction and thermal insulation layer inside deep-sea submersibles, sound insulation pads on offshore platform decks, and sound-absorbing and fireproof partitions for ship cabins (suitable for seawater corrosion and lightweight buoyancy requirements).

[0140] Special environmental building scenarios: anti-corrosion and noise reduction walls in chemical workshops (resistant to acid and alkali corrosion), sound-absorbing covers for underground integrated pipe corridors (moisture-resistant and lightweight), and fireproof and sound-absorbing ceilings for high-rise buildings (flame retardant and low thermal conductivity).

[0141] Equipment application scenarios: noise reduction and heat insulation shell for industrial boilers / refrigeration equipment.

[0142] The testing methods for the above performance are based on the following standards:

[0143] The testing standards for room temperature mechanical properties, chemical corrosion resistance, low thermal conductivity, sound absorption and noise reduction properties, and lightweight structural properties are the same as in Example 1;

[0144] Waterproof and oil-resistant properties: GB / T24127-2009 "Materials for Pressure-Resistant Structures of Deep-Sea Submarines";

[0145] Flame retardant properties: GB8624-2012 "Classification of Burning Performance of Building Materials and Products", GB / T2408-2021 "Determination of Burning Performance of Plastics - Horizontal and Vertical Burning Methods".

[0146] Example 3

[0147] This embodiment provides a multifunctional composite material, the raw material composition of which is as follows, by weight parts:

[0148] Lightweight aggregates: 17 parts expanded graphite (30-50 mesh, expansion ratio of 200 times), 11 parts 3M VS5500 hollow glass microspheres (40-60μm), 15 parts fly ash cenospheres (40-60 mesh), 16 parts closed-cell perlite (100-120 mesh), 6 parts nitrile rubber powder (>300 mesh, crushed by liquid nitrogen), and 9 parts bamboo and wood chips (100-150 mesh);

[0149] Lightweight filler: 12 parts of lightweight calcium carbonate (1250 mesh, whiteness 95%), 8 parts of gypsum dihydrate (80 mesh), 7 parts of bentonite (200 mesh), and 6 parts of desulfurized gypsum (80 mesh);

[0150] Cementitious materials: 45 parts of PO42.5 silicate cement, 15 parts of early-strength sulfoaluminate cement (42.5 grade), 8 parts of mineral powder (S95 grade), 8 parts of magnesium oxychloride cement (MgO content of 85%), and 8 parts of blast furnace water-quenched slag.

[0151] Surface treatment agents: 2 parts of KH550 (γ-aminopropyltriethoxysilane) anhydrous ethanol solution (KH550 is added to anhydrous ethanol and stirred evenly to obtain a 2wt% solution), 3 parts of sodium methylsilicate aqueous solution (sodium methylsilicate is added to water and stirred evenly to obtain a 5wt% solution), 2 parts of fluorocarbon emulsion toluene solution (fluorocarbon emulsion is added to toluene and stirred evenly to obtain a 4wt% solution), 2 parts of polyamide resin xylene solution (polyamide resin is added to xylene and stirred evenly to obtain a 5wt% solution), and 2 parts of styrene-acrylic emulsion aqueous solution (styrene-acrylic emulsion is added to water and stirred evenly to obtain a 5wt% solution).

[0152] Additives: 0.5 parts of naphthalene-based water-reducing agent (30% solid content), 0.25 parts of organosilicon defoamer (10% solid content), 2 parts of lithium chloride, and 2 parts of sulfate expanding agent;

[0153] The preparation method of the above-mentioned multifunctional composite material includes the following steps:

[0154] Weigh each ingredient accurately according to the weight proportions;

[0155] Lightweight aggregate pretreatment: Bamboo and wood chips were mixed with KH550 anhydrous ethanol solution, stirred at 250 rpm for 30 minutes, and dried at 40℃ for 8 hours; Closed-cell perlite was mixed with sodium methylsilicate aqueous solution, stirred at 200 rpm for 30 minutes, and dried at 60℃ for 6 hours; Fly ash cenospheres were mixed with fluorocarbon emulsion toluene solution, stirred at 200 rpm for 25 minutes, and dried at 60℃ for 5 hours; Expanded graphite was mixed with polyamide resin xylene solution, stirred at 200 rpm for 25 minutes, and dried at 60℃ for 5 hours; 3M VS5500 hollow glass microspheres were mixed with styrene-acrylic emulsion aqueous solution, stirred at 200 rpm for 25 minutes, and dried at 50℃ for 6 hours.

[0156] Preparation of Material A: Add the pretreated lightweight aggregate, nitrile rubber powder and lightweight filler to a mixer and dry mix at 180 rpm for 9 minutes to obtain a uniform Material A (low-speed dry mixing avoids breaking bamboo and wood chips).

[0157] Preparation of Material B: Dissolve lithium chloride and sulfate expansion agent in 26 parts of water, add PO42.5 silicate cement, early strength sulfoaluminate cement, mineral powder, magnesium oxychloride cement and blast furnace water-quenched slag, stir at 220 rpm for 6 minutes, add naphthalene-based water-reducing agent and organosilicon defoamer and continue stirring for 2 minutes to obtain Material B (magnesium oxychloride cement is added later to avoid premature setting).

[0158] Composite molding: Add material A to material B, stir at 200 rpm for 15 minutes, pour into a 400mm×400mm×30mm mold, mold under 3MPa pressure, cure at 60℃ for 4 hours, and then cure at room temperature (25±2℃) for 28 days to obtain a multifunctional composite material.

[0159] SEM image of the multifunctional composite material prepared in Example 3 is shown below. Figure 3 As shown, the interwoven needle-like / fibrous crystalline phases cement with the hydration products of vanadium-titanium steel slag to form a flame-retardant phase. Simultaneously, the interface between the bamboo and wood fiber matrix and the closed-cell perlite particles is tightly bonded. The flame-retardant modified bamboo and wood fibers are tightly integrated with the matrix, making them less prone to detachment and disintegration during combustion, thus maintaining the integrity of the flame-retardant structure. This meets the core performance requirements of flame-retardant and antistatic materials in underground coal mines.

[0160] The performance indicators of the multifunctional composite material prepared in this embodiment are as follows:

[0161] Mechanical properties at room temperature: 28-day compressive strength is 15.2 MPa, tensile strength is 2.3 MPa, and elongation at break is 4.5%; Water and oil resistance: After 90 days in an environment with 95% relative humidity, the volumetric water absorption rate is 7.2%; after immersion in diesel fuel for 72 hours, there is no blistering or peeling on the surface; Chemical corrosion resistance: After immersion in 5wt% hydrochloric acid solution for 30 days: compressive strength retention rate is 73%, tensile strength retention rate is 70%, elongation at break retention rate is 68%, and there are no obvious corrosion pits or peeling on the surface. After soaking in 5wt% sulfuric acid solution for 30 days: compressive strength retention rate was 76% (consistent with the original data), tensile strength retention rate was 72%, and elongation at break retention rate was 70%, with no delamination or pulverization; after soaking in acidic coal mine water (pH=4-5) for 90 days: compressive strength retention rate was 80%, tensile strength retention rate was 77%, and elongation at break retention rate was 75%, fully adaptable to the acidic environment of mines, and the changes in mechanical properties after acid leaching met the requirements of GB / T50082-2009; after soaking in 10wt% hydroxide solution... After immersion in sodium solution for 30 days: compressive strength retention rate was 81%, tensile strength retention rate was 78%, and elongation at break retention rate was 76%. No powdering or cracking was observed on the surface, and the structural integrity remained good. After immersion in 8wt% potassium hydroxide solution for 60 days: compressive strength retention rate was 75%, tensile strength retention rate was 73%, and no swelling or discoloration was observed. Excellent alkali resistance was demonstrated, and alkali solution corrosion met the requirements of GB / T50082-2009. Regarding thermal conductivity: steady-state thermal conductivity was 0.065 W / (m·K). Regarding flame retardancy... Surface finish: Oxygen index is 34% (meeting GB8624-2012 B1 grade flame retardant standard), no open flame combustion in coal mine special flame retardant test, smoldering time ≤5s, meeting MT / T113-2019 coal mine safety requirements; High temperature adaptability: after 72h constant temperature baking at 120℃, compressive strength retention rate is 82%, no melting or dripping under short-term high temperature at 150℃, flame retardant performance does not decrease after 72h constant temperature baking, suitable for high temperature working conditions; Lightweight structure: Bulk density is 0.69g / cm³. 3 The compressive strength is 3.7 MPa; flame retardancy and antistatic properties work synergistically: surface resistivity ≤ 1 × 10⁻⁶. 8 Ω, volume resistivity ≤1×10 9 Ω, meeting the anti-static requirements of underground coal mines and preventing static electricity from igniting gas; no dangerous combustion products: smoke density level (SDR) ≤45 during combustion, no toxic gas release (carbon monoxide release ≤1000ppm), ensuring the safety of personnel in confined spaces.

[0162] The specific application scenarios of the multifunctional composite material prepared in this embodiment are as follows:

[0163] Core applications in underground coal mines: fireproof and sound-absorbing linings for underground coal mine roadways (suitable for gas environments, flame-retardant and anti-static), soundproof and fireproof partitions for underground equipment chambers, support materials for coal mining faces (resistant to acidic water corrosion and flame-retardant), and thermal insulation and soundproofing layers for underground refuge chambers (free from toxic fumes).

[0164] Underground engineering scenarios: Fireproof and noise-reducing panels for subway tunnels (flame retardant B1 grade + sound absorption), fireproof partition walls for underground integrated pipe corridors (moisture resistant + flame retardant), and sound-absorbing and fireproof materials for enclosed spaces in civil defense projects (low smoke toxicity + lightweight).

[0165] High-risk industrial scenarios: flame-retardant and corrosion-resistant walls in chemical workshops (including acid and alkali corrosion), protective panels for equipment in oil and gas field extraction areas (flame-retardant, anti-static, and corrosion-resistant), and noise-reducing and fireproof ceilings in mining and mineral processing plants (suitable for acidic mining environments).

[0166] Special equipment scenarios: noise reduction and flame retardant pads for underground coal mine transportation equipment (mine cars, belt conveyors), sound-absorbing and flame retardant panels for industrial explosion-proof workshops, and fireproof and heat-insulating materials around high-temperature equipment (such as coking ovens).

[0167] The testing methods for the above performance are based on the following standards:

[0168] The testing standards for room temperature mechanical properties, chemical corrosion resistance, low thermal conductivity, and lightweight structure are the same as in Example 1;

[0169] Waterproof and oil-resistant properties: GB / T50108-2008 "Technical Specification for Waterproofing of Underground Engineering";

[0170] Flame retardant performance: GB8624-2012 "Classification of Burning Performance of Building Materials and Products", MT / T113-2019 "General Test Methods and Judgment Rules for Flame Retardant and Antistatic Properties of Polymer Products Used in Coal Mines";

[0171] High temperature adaptability: MT / T113-2019 "General test methods and judgment rules for flame retardancy and antistatic properties of polymer products used in underground coal mines".

[0172] Example 4

[0173] This embodiment provides a multifunctional composite material, the raw material composition of which is as follows, by weight parts:

[0174] Lightweight aggregates: 16 parts expanded graphite (30-50 mesh, expansion ratio of 200 times), 10 parts 3M VS5500 hollow glass microspheres (40-60μm), 8 parts nitrile rubber powder (>300 mesh liquid nitrogen crushing), 20 parts foam glass cutting waste powder (100 mesh), 12 parts vanadium-titanium steel slag (80 mesh), and 8 parts 3mm short reed stalks;

[0175] Lightweight filler: 12 parts of lightweight calcium carbonate (1250 mesh, whiteness 95%), 7 parts of gypsum dihydrate (80 mesh), 6 parts of bentonite (200 mesh), and 7 parts of lithium slag (80 mesh);

[0176] Cementitious materials: 48 parts of PO52.5 silicate cement, 12 parts of early-strength sulfoaluminate cement (42.5 grade), 10 parts of mineral powder (S95 grade), 6 parts of blast furnace water-quenched slag, and 8 parts of magnesium phosphate cement.

[0177] Surface treatment agents: 3 parts of KH560 isopropanol solution (KH560 is added to isopropanol and stirred evenly to obtain a 2wt% solution), 3 parts of sodium methylsilicate aqueous solution (sodium methylsilicate is added to water and stirred evenly to obtain a 5wt% solution), 2 parts of fluorocarbon emulsion acetone solution (fluorocarbon emulsion is added to acetone and stirred evenly to obtain a 4wt% solution), 2 parts of polyamide resin xylene solution (polyamide resin xylene is added to xylene and stirred evenly to obtain a 5wt% solution), and 1 part of chloroprene rubber emulsion aqueous solution (chloroprene rubber emulsion (solid content of 40wt% (the standard solid content commonly used in industry, to ensure the dispersion stability after the preparation of 10wt% aqueous solution)) is added to water and stirred evenly to obtain a 10wt% solution).

[0178] Additives: 0.5 parts aliphatic water-reducing agent (30% solid content), 0.2 parts organosilicon defoamer (10% solid content), 0.7 parts lithium sulfate, and 2 parts sodium aluminate;

[0179] The preparation method of the above-mentioned multifunctional composite material includes the following steps:

[0180] Weigh each ingredient accurately according to the weight proportions;

[0181] Lightweight aggregate pretreatment: Foam glass cutting waste powder was mixed with KH560 isopropanol solution, stirred at 200 rpm for 25 minutes, and dried at 50℃ for 6 hours; vanadium-titanium steel slag was mixed with fluorocarbon emulsion acetone solution, stirred at 200 rpm for 25 minutes, and dried at 60℃ for 5 hours; 3mm chopped reeds were mixed with chloroprene rubber emulsion aqueous solution, stirred for 30 minutes, and dried at 40℃ for 8 hours; expanded graphite was mixed with polyamide resin xylene solution, stirred at 200 rpm for 25 minutes, and dried at 60℃ for 5 hours; 3M VS5500 hollow glass microspheres were mixed with sodium methylsilicate aqueous solution, stirred at 200 rpm for 25 minutes, and dried at 60℃ for 6 hours.

[0182] Preparation of Material A: Add the pretreated lightweight aggregate, expanded graphite and lightweight filler to the mixer and dry mix at 220 rpm for 7 minutes to obtain uniform Material A (to ensure uniform dispersion of vanadium-titanium steel slag and improve overall wear resistance).

[0183] Preparation of Material B: Dissolve lithium sulfate and sodium aluminate in 24 parts of water, add PO52.5 silicate cement, early strength sulfoaluminate cement, mineral powder, blast furnace water-quenched slag and magnesium phosphate cement, stir at 250 rpm for 6 minutes, add aliphatic water-reducing agent and organosilicon defoamer and continue stirring for 1 minute to obtain Material B.

[0184] Composite molding: Add material A to material B, stir at 250 rpm for 12 minutes, pour into a 500mm×500mm×20mm mold (fitted to the size of workshop floor tiles), compact with 3MPa pressure (to improve surface density and prevent acid and alkali penetration), and cure at room temperature (25±2℃) for 28 days to obtain a multifunctional composite material.

[0185] SEM image of the multifunctional composite material prepared in Example 4 is shown below. Figure 4 As shown, the multifunctional composite material prepared in this embodiment exhibits a dense particle packing morphology. The vanadium-titanium steel slag wear-resistant particles in the ingredients are uniformly embedded in the matrix, and the particle-matrix interface is tightly bonded. This uniformly dispersed structure can enhance the wear resistance of the material surface and resist frequent friction from the ground; it also improves the structural stability of the multifunctional composite material in acid and alkali environments and avoids failure caused by corrosive media eroding the interface.

[0186] The performance indicators of the multifunctional composite material prepared in this embodiment are as follows:

[0187] Room temperature mechanical properties: 28-day compressive strength is 16.5 MPa, tensile strength is 2.5 MPa, elongation at break is 4.8%, and Shore D hardness is 65. Water and oil resistance: No leakage after 96 hours of tap water immersion; 92% Shore D hardness retention after 72 hours of machine oil immersion. Chemical corrosion resistance: After 30 days of immersion in 10wt% hydrochloric acid solution: tensile strength retention is 75%, compressive strength retention is 78%, elongation at break retention is 73%, and there are no corrosion pits or peeling on the surface. After 30 days of immersion in 5wt% sulfuric acid solution: compressive strength... The strength retention rate was 76%, the tensile strength retention rate was 73%, and the elongation at break retention rate was 71%, with no delamination or powdering. After immersion in a 3wt% nitric acid solution (a commonly used strong acid in chemical engineering) for 30 days: the compressive strength retention rate was 74%, the tensile strength retention rate was 70%, and the elongation at break retention rate was 69%. The resistance to strong oxidizing acids met the standards, and the changes in mechanical properties after acid immersion complied with GB / T50082-2009 requirements. After immersion in a 10wt% sodium hydroxide solution for 30 days: the compressive strength retention rate was 83%, and the tensile strength retention rate was 72% (compared to the original data). The surface exhibits excellent resistance to alkali penetration, with a 78% elongation at break retention rate and no powdering or cracking. After immersion in an 8wt% potassium hydroxide solution for 60 days, the compressive strength retention rate is 77%, the tensile strength retention rate is 70%, and the elongation at break retention rate is 75%, with no swelling or discoloration and good structural integrity. After immersion in a 5wt% sodium carbonate solution for 90 days (a common medium in industrial alkaline wastewater), the compressive strength retention rate is 80%, and the tensile strength retention rate is 76%, making it suitable for alkaline wastewater treatment applications. Alkaline solution corrosion complies with GB / T50082-2009 standards. Requirements: Low thermal conductivity: steady-state thermal conductivity 0.062 W / (m·K); Flame retardancy: oxygen index 33%, burning time ≤8s in vertical burning test, no ignition drips; High temperature adaptability: compressive strength retention rate 87% after baking at 150℃ for 72h, no carbonization or cracking after short-term (30min) high temperature at 200℃; Sound absorption and noise reduction: sound absorption coefficient 0.45-0.62 in the 250-2000Hz frequency band, noise reduction coefficient (NRC) 0.52; Lightweight structure: bulk density 0.67 g / cm³. 3 Surface density ≤18kg / m³ 2 .

[0188] Based on the core advantages of the multifunctional composite material in this embodiment—"high acid and alkali resistance, wear resistance, flame retardancy, sound absorption, and lightweight"—and using recycled raw materials such as foam glass cutting waste and vanadium-titanium steel slag, it is primarily applied in the following scenarios:

[0189] Industrial flooring / lining applications: acid and alkali resistant floor tiles in chemical workshops (suitable for acid and alkali waste liquid corrosion, 500mm×500mm size for direct installation), anti-corrosion and wear-resistant floor linings in electroplating plants, and acid-resistant slag slurry flooring in mining and mineral processing workshops (vanadium-titanium steel slag enhances wear resistance).

[0190] Environmental recycling engineering scenarios: sound-absorbing and corrosion-resistant walls for construction waste recycling plants (reusing waste materials, green and environmentally friendly), noise-reducing and corrosion-resistant ceilings for foam glass production workshops, and seepage-proof linings for industrial solid waste landfills (seepage-resistant and corrosion-resistant).

[0191] Building and underground engineering scenarios: moisture-resistant and corrosion-resistant sound-absorbing floor tiles for underground garages, corrosion-resistant and sound-absorbing panels for sewage treatment plant structures (resistant to acid and alkali wastewater corrosion), and corrosion-resistant and noise-reducing materials for secondary tunnel lining (lightweight + low thermal conductivity).

[0192] Equipment protection scenarios: wear-resistant and corrosion-resistant lining for chemical reactor base, noise-reducing and flame-retardant lining for industrial fan outlet, and fireproof and heat-insulating panels around high-temperature equipment (high strength retention rate after baking at 150℃).

[0193] The testing methods for the above performance are based on the following standards:

[0194] The testing standards for room temperature mechanical properties, low thermal conductivity, sound absorption and noise reduction properties, and lightweight structural properties are the same as in Example 1;

[0195] Water and oil resistance performance: GB / T1733-1993 "Determination of water resistance of paint film", GB / T25252-2010 "Test method for stain resistance of exterior wall coatings for building".

[0196] Chemical resistance: GB / T1763-1979 "Determination of Chemical Resistance of Coatings";

[0197] Flame retardant properties: GB8624-2012 "Classification of Burning Performance of Building Materials and Products", GB / T2408-2021 "Determination of Burning Performance of Plastics - Horizontal and Vertical Burning Methods";

[0198] High temperature adaptability: GB / T1735-2009 "Determination of heat resistance of paints and varnishes".

[0199] Example 5

[0200] This embodiment provides a multifunctional composite material, the raw material composition of which is as follows, by weight parts:

[0201] Lightweight aggregate: 14 parts expanded graphite (30-50 mesh, expansion ratio 200 times), 12 parts 3M VS5500 hollow glass microspheres (40-60μm), and aerogel powder (specific surface area ≥600m²). 2 10 parts of / g), 18 parts of diatomaceous earth (200 mesh), 15 parts of 3mm chopped wheat straw, and 12 parts of expanded perlite (80-120 mesh);

[0202] Lightweight filler: 10 parts of lightweight calcium carbonate (1250 mesh, whiteness 95%), 6 parts of gypsum dihydrate (80 mesh), 5 parts of bentonite (200 mesh), and 6 parts of talc (400 mesh);

[0203] Cementing materials: 42 parts of PO42.5 silicate cement, 10 parts of early-strength sulfoaluminate cement (42.5 grade), 15 parts of mineral powder (S95 grade), 6 parts of silica sol (solid content of 30%), and 7 parts of alkali-activated cement (composed of water glass (modulus of 1.3) and sodium hydroxide in a mass ratio of 4:1).

[0204] Surface treatment agents: 3 parts of KH570 isopropanol solution (KH570 is added to isopropanol and stirred evenly to obtain a 2wt% solution), 2 parts of sodium methylsilicate aqueous solution (sodium methylsilicate is added to water and stirred evenly to obtain a 5wt% solution), 2 parts of fluorocarbon emulsion acetone solution (fluorocarbon emulsion is added to acetone and stirred evenly to obtain a 4wt% solution), 2 parts of polyamide resin xylene solution (polyamide resin is added to xylene and stirred evenly to obtain a 5wt% solution), and 2 parts of styrene-acrylic emulsion aqueous solution (styrene-acrylic emulsion is added to water and stirred evenly to obtain a 5wt% solution).

[0205] Additives: 0.3 parts of polycarboxylate superplasticizer (40% solid content), 0.2 parts of silicone defoamer (10% solid content), 1 part of aluminum sulfate octadecylhydrate, and 2 parts of calcium silicate whiskers;

[0206] The preparation method of the above-mentioned multifunctional composite material includes the following steps:

[0207] Weigh each ingredient accurately according to the weight proportions;

[0208] Lightweight aggregate pretreatment: Diatomaceous earth was mixed with KH570 isopropanol solution, stirred at 200 rpm for 30 minutes, and dried at 50℃ for 6 hours; 3mm chopped straw was mixed with styrene-acrylic emulsion aqueous solution, soaked for 30 minutes, and dried at 40℃ for 8 hours; expanded perlite was mixed with sodium methylsilicate aqueous solution, stirred at 200 rpm for 25 minutes, and dried at 60℃ for 6 hours; aerogel powder was mixed with fluorocarbon emulsion acetone solution, ultrasonically dispersed for 20 minutes, and dried at 50℃ for 6 hours; 3M VS5500 hollow glass microspheres were mixed with polyamide resin xylene solution, stirred at 200 rpm for 25 minutes, and dried at 50℃ for 6 hours.

[0209] Preparation of Material A: Add the pretreated lightweight aggregate, expanded graphite, lightweight filler and hydrated calcium silicate whiskers to a mixer and dry mix at 200 rpm for 8 minutes to obtain a uniform Material A (low-speed mixing avoids damage to the sound-absorbing pores).

[0210] Preparation of Material B: Dissolve aluminum sulfate octadecylhydrate in 23 parts of water, add PO42.5 silicate cement, early-strength sulfoaluminate cement, mineral powder, silica sol and alkali-activated cement, stir at 250 rpm for 5 minutes, add polycarboxylate superplasticizer and organosilicon defoamer and continue stirring for 2 minutes to obtain Material B (the defoamer reduces bubbles to avoid affecting the sound absorption frequency band).

[0211] Composite molding: Add material A to material B, stir at 200 rpm for 10 minutes, pour into a 600mm×600mm×100mm mold (to match the wall thickness and ensure sound absorption effect), compact with 1.5MPa pressure (light compaction to retain sound absorption pores), and cure at room temperature (25±2℃) for 28 days to obtain a multifunctional composite material.

[0212] SEM image of the multifunctional composite material prepared in Example 5 is shown below. Figure 5 As shown, the multifunctional composite material prepared in this embodiment exhibits a large number of interconnected pore networks. The chopped straw fibers are dispersed and interwoven, forming the supporting skeleton of the pore structure. The diatomaceous earth and the fiber gaps are interconnected, forming interconnected pores with a wide pore size. At the same time, a fine modified protective layer is visible on the pore walls, corresponding to the modified treatment components in the ingredients.

[0213] The performance indicators of the multifunctional composite material prepared in this embodiment are as follows:

[0214] Room temperature mechanical properties: At room temperature, the 28-day compressive strength is 14.3 MPa, the tensile strength is 2.2 MPa, and the elongation at break is 4.6%. Water and oil resistance: After immersion in rainwater for 96 hours, the volumetric water absorption rate is 6.8%; after immersion in engine oil for 72 hours, the surface shows no swelling or discoloration. Chemical corrosion resistance: After immersion in 5wt% sulfuric acid solution for 30 days: the compressive strength retention rate is 78%, the tensile strength retention rate is 75%, and the elongation at break retention rate is 73%, with no corrosion marks or peeling on the surface; After immersion in 10wt% hydrochloric acid solution for 30 days: the compressive strength retention rate is 74%, and the tensile strength retention rate is 75%. The compressive strength retention rate was 71%, the elongation at break retention rate was 69%, and there was no delamination or powdering. After soaking in 3wt% nitric acid solution for 30 days: the compressive strength retention rate was 72%, the tensile strength retention rate was 69%, and the elongation at break retention rate was 67%. The resistance to strong oxidizing acids met the standards, and the changes in mechanical properties after acid immersion complied with GB / T50082-2009 requirements. After soaking in 5wt% sodium hydroxide solution for 30 days: the compressive strength retention rate was 75%, the tensile strength retention rate was 73%, and the elongation at break retention rate was 71%. The surface showed no powdering or cracking, and the alkali resistance was good. After soaking in 8wt% sodium hydroxide solution... After immersion in potassium chloride solution for 60 days: compressive strength retention rate was 70%, tensile strength retention rate was 68%, and elongation at break retention rate was 66%, with no swelling or discoloration, and structural integrity remained unaffected; after immersion in 5wt% sodium carbonate solution for 90 days (industrial alkaline medium): compressive strength retention rate was 72%, tensile strength retention rate was 70%, and elongation at break retention rate was 69%, suitable for long-term use in alkaline environments, and alkaline solution corrosion met the requirements of GB / T50082-2009; in terms of low thermal conductivity: steady-state thermal conductivity was 0.068 W / (m·K); in terms of flame retardancy: oxygen index was 32. In vertical combustion tests, the flame height was ≤120mm, with no molten dripping. Regarding high-temperature adaptability: after baking at 120℃ for 72 hours, the compressive strength retention rate was 83%, and after 30 cycles of thermal cycling from -30℃ to 120℃, there was no cracking or delamination. In terms of sound absorption and noise reduction: the sound absorption coefficient in the 250-2000Hz frequency band was 0.55-0.85 (with outstanding mid-to-high frequency sound absorption, covering the core frequency band of everyday noise), and the noise reduction coefficient (NRC) was 0.58. The interconnected pores retained by the light compaction process improved the sound absorption efficiency. Regarding structural lightweighting: the bulk density was 0.65g / cm³. 3 Surface density ≤20kg / m 2 .

[0215] The multifunctional composite material in this embodiment uses 3mm chopped wheat straw (recycled agricultural waste) and diatomaceous earth (natural mineral raw material) to achieve resource recycling, which aligns with the trend of green building materials development. It exhibits no cracking or delamination after 30 cycles of thermal cycling from -30℃ to 120℃, making it suitable for extreme temperature environments. After baking at a constant temperature of 120℃, it retains 83% of its strength, demonstrating excellent stability. Specific application scenarios (combining sound absorption, environmental protection, and weather resistance) are as follows:

[0216] Based on the material's core advantages of "high sound absorption + agricultural waste recycling + high and low temperature resistance + corrosion resistance and lightweight", it is mainly applied in the following scenarios:

[0217] Architectural acoustic decoration scenarios: acoustic ceilings for concert halls / theaters (600mm×600mm size for standardized construction), acoustic decorative panels for conference rooms / classrooms (high NRC value for noise reduction), and acoustic partitions for residential partition walls (lightweight + low thermal conductivity, with both thermal insulation and noise reduction).

[0218] Agricultural waste recycling projects include: sound-absorbing walls for straw resource utilization projects, noise reduction and heat insulation materials for rural living environment renovation (suitable for rural building needs), and sound-absorbing and heat-insulating linings for agricultural greenhouses (resistant to high and low temperature cycles, suitable for temperature changes inside the greenhouse).

[0219] Noise reduction scenarios for HVAC and equipment: noise reduction insulation layer for central air conditioning ducts (low thermal conductivity + sound absorption synergy), sound-absorbing cover for fan coil units (flame retardant + no dripping), noise reduction lining for cooling towers (rain resistant + moisture resistant, low volume water absorption).

[0220] Extreme environment building scenarios: thermal insulation and sound absorption panels for exterior walls of buildings in cold regions (no cracking at -30℃), auxiliary noise reduction and heat insulation materials for high-temperature workshops (stable strength after baking at 120℃), and anti-corrosion and sound-absorbing walls for low-rise buildings in coastal areas (acid and alkali resistant + moisture resistant).

[0221] The testing methods for the above performance are based on the following standards:

[0222] The testing standards for room temperature mechanical properties, chemical corrosion resistance, low thermal conductivity, and sound absorption and noise reduction properties are the same as in Example 1;

[0223] Water and oil resistance performance: GB / T1733-1993 "Determination of water resistance of paint film", GB / T25252-2010 "Test method for stain resistance of exterior wall coatings for building".

[0224] Flame retardant properties: GB8624-2012 "Classification of Burning Performance of Building Materials and Products", GB / T2408-2021 "Determination of Burning Performance of Plastics - Horizontal and Vertical Burning Methods";

[0225] High temperature adaptability: GB / T25975-2010 "Materials for External Thermal Insulation Systems of Buildings";

[0226] Lightweight structural performance: GB / T11968-2006 Autoclaved Aerated Concrete Blocks, GB / T23451-2009 Lightweight Partition Panels for Buildings.

[0227] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A multifunctional composite material, characterized in that, The raw materials include: lightweight aggregates, lightweight fillers, cementitious materials, surface treatment agents, additives, and water; The lightweight aggregate is composed of four of the following: fly ash cenospheres, nitrile rubber powder, foam glass cutting waste powder, pre-degreased rapeseed, aerogel powder, expanded vermiculite, lightweight ceramsite powder, closed-cell perlite, bamboo and wood chips, vanadium-titanium steel slag, chopped straw, diatomite, and expanded perlite, combined with expanded graphite and hollow glass microspheres. The lightweight filler is composed of one of lithium slag, silica, desulfurized gypsum and talc powder, combined with lightweight calcium carbonate, gypsum dihydrate and bentonite. The cementitious material is composed of two of the following: blast furnace water-quenched slag, magnesium phosphate cement, silica sol, alkali-activated cement, magnesium oxychloride cement, and blast furnace water-quenched slag cement, combined with silicate cement, early-strength sulfoaluminate cement, and mineral powder. The surface treatment agent is selected from five of the following: silane coupling agent isopropanol or anhydrous ethanol solution, sodium methylsilicate aqueous solution, polyamide resin xylene solution, chloroprene rubber latex aqueous solution, silicone acrylic latex anhydrous ethanol solution, styrene acrylic latex aqueous solution, and fluorocarbon latex acetone or toluene solution. The additive is composed of at least one of aluminum sulfate, sodium aluminate, lithium salt, sulfate expanding agent and hydrated calcium silicate whiskers, combined with a water reducing agent and an organosilicon defoamer.

2. The multifunctional composite material according to claim 1, characterized in that, The bulk density of the hollow glass microspheres is 0.15-0.3 g / cm³. 3 The thermal conductivity is 0.03-0.05 W / (m·K); the bulk density of the aerogel powder is ≤0.1 g / cm³. 3 Thermal conductivity ≤ 0.02 W / (m·K), specific surface area ≥ 600 m² 2 / g; the bulk density of the fly ash cenospheres is 0.4-0.6 g / cm³. 3 The thermal conductivity of the expanded graphite is 0.06-0.10 W / (m·K), and the expansion ratio is 200 times.

3. The multifunctional composite material according to claim 1, characterized in that, The expanded graphite has a mesh size of 30-50 mesh; the hollow glass microspheres have a particle size of 40-60 μm; the nitrile rubber powder has a mesh size >300 mesh; the fly ash cenospheres have a mesh size of 40-60 mesh; the foam glass cutting waste powder has a mesh size of 100 mesh; the pre-de-oiled rapeseed has a particle size of 2-3 mm; the expanded vermiculite has a particle size of 2-5 mm; the lightweight ceramsite powder has a mesh size of 100 mesh; the closed-cell perlite has a mesh size of 100-120 mesh; the bamboo and wood chips have a mesh size of 100-150 mesh; the vanadium-titanium steel slag has a mesh size of 80 mesh; the chopped straw has a particle size of 3 mm; the diatomaceous earth has a mesh size of 200 mesh; and the expanded perlite has a mesh size of 80-120 mesh.

4. The multifunctional composite material according to claim 1, characterized in that, The light calcium carbonate has a mesh size of 1250 and a whiteness of 95%; the gypsum dihydrate has a mesh size of 80; the bentonite has a mesh size of 200; the lithium slag has a mesh size of 80; the talc has a mesh size of 400; the desulfurized gypsum has a mesh size of 80; and the silica has a mesh size of 800.

5. The multifunctional composite material according to claim 1, characterized in that, The silicate cement is PO42.5 silicate cement or PO52.5 silicate cement; the early-strength sulfoaluminate cement is grade 42.5 early-strength sulfoaluminate cement; the mineral powder is grade S95 mineral powder; and the silica sol has a solid content of 30%.

6. The multifunctional composite material according to claim 1, characterized in that, The silane coupling agent is selected from one of γ-glycidoxypropyltrimethoxysilane, 3-(isobutenoyloxy)propyltrimethoxysilane, methyltrimethoxysilane, and γ-aminopropyltriethoxysilane; And / or, the lithium salt is selected from lithium carbonate, lithium chloride and lithium sulfate; And / or, the water-reducing agent is selected from one of polycarboxylate water-reducing agents, naphthalene-based water-reducing agents, or aliphatic water-reducing agents; And / or, the chopped straw is selected from chopped reed stalks or chopped wheat straw.

7. The multifunctional composite material according to claim 1, characterized in that, The concentration of the silane coupling agent is 1.5-2 wt% in isopropanol or anhydrous ethanol solution, the concentration of the sodium methylsilicate aqueous solution is 5 wt%, the concentration of the polyamide resin xylene solution is 5 wt%, the concentration of the chloroprene rubber latex aqueous solution is 10 wt%, the concentration of the styrene-acrylic latex aqueous solution is 5 wt%, the concentration of the fluorocarbon latex acetone or toluene solution is 4 wt%, and the concentration of the silicone-acrylic latex anhydrous ethanol solution is 4 wt%.

8. The multifunctional composite material according to claim 1, characterized in that, By weight, the lightweight aggregate comprises 74-81 parts, the lightweight filler comprises 27-33 parts, the cementitious material comprises 80-84 parts, the surface treatment agent comprises 11 parts, the admixture comprises 3.2-4.75 parts, and the water comprises 22-26 parts.

9. A method for preparing a multifunctional composite material according to any one of claims 1-8, characterized in that, Includes the following steps: Weigh each ingredient accurately according to the weight proportions; Some lightweight aggregates were pretreated with a surface treatment agent; Pretreated lightweight aggregate, untreated lightweight aggregate, and lightweight filler are mixed and dry-mixed to obtain material A. Dissolve the additives other than water-reducing agent and silicone defoamer in water, add the gelling material, stir, then add water-reducing agent and silicone defoamer, stir again to obtain material B; Material A is added to material B, stirred, molded, and cured to obtain the multifunctional composite material.

10. The application of a multifunctional composite material as described in any one of claims 1-8 in the preparation of a material that simultaneously meets the requirements of corrosion resistance, buoyancy support, lightweight insulation and safety protection.

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