Preparation method of multifunctional high-performance gel-based composite material

Abstract

The invention discloses a preparation method of a multifunctional high-performance gelling-based composite material, and belongs to the technical field of production of gelling-based composites.The preparation method comprises the following steps that the gelling-based composite material is treated; carrying out three-dimensional wrapping on the gel-based composite material by using the resin-based continuous fiber fabric prepreg; and hot-press molding: putting the three-dimensionally wrapped gel-based composite material into a hot-press curing machine or an autoclave for curing and molding to obtain a multifunctional high-performance gel-based composite material finished product. According to the invention, the ultrahigh mechanical property of the solid waste-containing gel-based composite material is efficiently realized, and the gel-based composite material is endowed with unique wear-resistant, heat-conducting and electric-conducting functions, so that a universal scheme can be provided for applying the gel-based composite material to functional building materials (such as electromagnetic shielding); and the method has the advantages of simple production process, easiness in operation and capability of realizing batch and continuous production, is suitable for modifying and compounding the vast majority of gel-based composite materials, and is suitable for popularization and application.

Description

Technical Field

[0001] The present invention belongs to the technical field of production of gel-based composite materials, and relates to a method for preparing a multifunctional high-performance gel-based composite material. Background Art

[0002] Cementitious composite materials (such as reinforced concrete, calcium silicate board, gypsum board, cement board, glass magnesium board, and various cementitious foam boards) are lightweight, fire-resistant, and high-temperature resistant. They are widely used in industries such as central air conditioning, construction, and the chemical industry, and are currently one of the most highly regarded green and environmentally friendly building materials. Cementitious composite materials are general-purpose engineering materials made from a cementitious material such as cement, gypsum, or lime. After hardening by reacting with water, they are then reinforced or modified with fibers (steel fiber, polymer fiber, glass fiber, etc.), polymer emulsions, admixtures, or functional fillers. Cement is the most widely used cementitious material, and as the world's largest cement producer and consumer, China consumes a significant amount of cementitious composites annually. China's annual cement consumption alone has consistently reached approximately 2.4 billion tons in recent years (accounting for over 50% of the global total), a significant portion of which is used to manufacture various cementitious composite materials. The global cementitious composites market has maintained steady growth, driven by the continued urbanization, infrastructure development, and demand for building renovation in emerging economies. Developed countries focus on high-performance, green products, while developing countries demand an increase in basic building materials, with an overall annual growth rate expected to be 3%-5%. However, as industry pursues environmental protection and a circular economy, green, low-carbon composite materials—using cement and other cementitious composite materials to consume industrial solid waste (i.e., solid materials), agricultural solid waste, and construction solid waste while reducing costs—have become extremely important development and research directions.

[0003] Industrial solid wastes that can be used in cementitious composite materials include: fly ash, phosphogypsum, granulated blast furnace slag, silica fume, tailings, waste glass powder, thermal power plant waste, etc. The above solid wastes have huge output and complex component elements, but they all contain some calcium, silicon and other elements that can partially participate in the cementitious reaction, and are therefore widely used in cementitious materials as cost-reducing components. Agricultural solid waste is often used as an alternative fiber component of cementitious materials, including sawdust, agricultural straw powder, waste bamboo powder, etc., but the pain point of using agricultural solid waste is how to convert large granular materials of agricultural solid waste into fibrous filament powder. The difficulty with construction solid waste is that it has completed the hydration reaction and can often only be introduced into cementitious materials as an inert additive. Existing studies have reported that supercritical carbonization of construction waste can be used and then applied to cementitious materials as a modified reinforcing material.

[0004] While the substantial addition of solid waste materials has resulted in ultra-low costs for cementitious composites, it has also significantly reduced the mechanical properties of many cementitious composites, such as low flexural strength. Improving the mechanical properties of cementitious composites has become a major challenge for many cementitious composites manufacturers.

[0005] Traditional solutions to improve the mechanical properties of cementitious composites include: double-sided wrapping of galvanized iron sheets on steel plates; internal blending of pulp fibers, organic fibers, and steel fibers; and the introduction of continuous glass fiber mesh cloth and non-woven fabrics during the molding process. These traditional solutions have the following drawbacks: 1) Although wrapping with galvanized iron sheets can improve performance, stress conduction is only provided by the glue between the cementitious sheet and the steel plate, and the complete wrapping of the cementitious parts by the steel cannot be achieved. The moisture absorption property of the cementitious parts easily causes the steel plates to become damp and rust, and the high density of steel prevents effective weight reduction. 2) The addition of various types of fibers (short fibers, fiber cloth) determines that they are only suitable for low-temperature curing boards (such as glass magnesium boards, cement boards, and gypsum boards). Once used in high-temperature molding fields such as calcium silicate boards, the high alkalinity of the cement material will cause the fibers to fail, making effective reinforcement impossible. No matter how much fiber is added, the reinforcement purpose cannot be achieved. For example, the bending strength of traditional calcium silicate boards is only about 15 MPa. Insufficient mechanical properties of cementitious composite materials may cause the cementitious composite materials used in pipelines to break or fall, and even seriously endanger the material and property safety and life safety of the people.

[0006] Therefore, traditional reinforcement and modification technologies cannot solve the problems of reinforcement, toughening, wear resistance, one-step decorative molding, and meeting various functional requirements of cementitious-based composite materials containing solid waste. Therefore, the development of highly versatile reinforcement and functional solutions is the core of the further development of cementitious-based composite materials. Summary of the Invention

[0007] The purpose of the present invention is to provide a method for preparing a multifunctional high-performance gel-based composite material in order to solve the above problems.

[0008] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0009] A method for preparing a multifunctional high-performance gel-based composite material comprises the following steps:

[0010] Step 1: Treating the cementitious composite material by one or more of drying, UV resin sealing, penetrating primer, and silicone resin sealing, and then cleaning the cementitious composite material; or directly cleaning the cementitious composite material;

[0011] Step 2: three-dimensionally wrapping the gel-based composite material with a resin-based continuous fiber fabric prepreg, with the number of wrapping layers being 1-10;

[0012] Step 3, hot pressing molding: placing the three-dimensionally wrapped gel-based composite material in a hot pressing curing machine or an autoclave for curing and molding. If a hot pressing curing machine is used, the process parameters are: preheating temperature of 60-100°C, preheating time of 20-100 minutes, hot pressing temperature of 120-150°C, hot pressing time of 60-180 minutes, and then naturally cooling or cooling to room temperature by water cooling to obtain a multifunctional high-performance gel-based composite material product; if an autoclave is used, the process parameters are: vacuuming from room temperature to -0.095MPa, heating to 70-80°C at 1-2°C / min, keeping warm for 50 minutes, then applying a pressure of 0.4-1MPa, heating to 120-140°C, keeping warm for 2-4 hours, cooling to 60°C and demolding to obtain a multifunctional high-performance gel-based composite material product.

[0013] According to actual needs, the cementitious composite material is cement board, fiber calcium silicate board, foamed ceiling gypsum board or glass magnesium board, and the product form is usually insulation pipe, insulation board, partition board, ceiling board or decorative board; the selection method is mainly to use cementitious base materials of different thicknesses and densities to meet different engineering needs, such as insulation, fire resistance, strength, hardness, etc.; if necessary, low-density, high-thickness boards can be used according to special engineering cases to meet the needs of fire resistance, explosion resistance, low-temperature resistance, etc.

[0014] Preferably, in step 1, the cementitious matrix composite material is treated by drying, UV resin sealing, penetrating primer, and silicone resin sealing. The cleaning process in step 1 is generally performed using a conventional surface vacuum cleaner, dry cloth, etc. to remove surface moisture and dust. Atmospheric plasma treatment may be used to enhance surface adhesion. Those skilled in the art may directly utilize appropriate surface cleaning and modification equipment based on specific needs.

[0015] According to actual needs, in step 2, the resin-based continuous fiber fabric prepreg is an epoxy resin-based glass fiber fabric prepreg, an epoxy resin-based carbon fiber fabric prepreg, an unsaturated resin-based glass fiber fabric prepreg, or an unsaturated resin-based carbon fiber fabric prepreg. Those skilled in the art can directly use conventional prepregs purchased on the market or prepare various prepreg sheets by themselves according to specific needs. For the three-dimensional wrapping in step 2, a commercially available fiber resin-based wrapping and winding molding machine can be customized to achieve three-dimensional wrapping molding of various types of gelled substrates. 1-10 layers of wrapping can be selected according to specific project requirements. If a low-cost alternative to organic glass fiber reinforced plastic parts (septic tanks) is required, 8-20 layers of prepreg wrapping molding can be selected; hand lay-up molding can also be selected as the winding molding method.

[0016] The beneficial effects of the present invention are:

[0017] The present invention utilizes the excellent molding operation performance of resin-based continuous fiber fabric prepreg to realize the three-dimensional winding molding production of various types of special-shaped or flat-plate-shaped cementitious composite materials. Through the strong adhesion of the resin, a strong combination between the resin-based continuous fiber fabric prepreg and the cementitious composite material can be achieved, and the absorption of carbon dioxide and moisture by the cementitious composite material during use is completely sealed, thereby inhibiting material deformation. Its bending strength can be as high as 85MPa, and it can be applied to the field of structural parts. It efficiently realizes the ultra-high mechanical properties of cementitious composite materials containing solid waste, and gives the cementitious composite materials unique wear resistance, thermal conductivity, and electrical conductivity. It can provide a universal solution for the application of cementitious composite materials in functional building materials (such as electromagnetic shielding), and has the advantages of simple production process, easy operation, batch production, and continuous production. It is suitable for the modification and compounding of most cementitious composite materials and is suitable for promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram comparing the bending properties of the multifunctional high-performance gel-based composite calcium silicate board produced by the present invention and the conventional gel-based calcium silicate board;

[0019] Figure 2 This is a schematic diagram of a secondary combustion test of a multifunctional high-performance gel-based composite calcium silicate board produced by the present invention;

[0020] Figure 3 This is a schematic diagram of the secondary combustion test of conventional gel-based calcium silicate board. DETAILED DESCRIPTION

[0021] The present invention will be further described below in conjunction with the embodiments and drawings:

[0022] The method for preparing the multifunctional high-performance gel-based composite material of the present invention comprises the following steps:

[0023] Step 1: Treat the cementitious composite material by one or more of drying, UV resin sealing, penetrating primer, and silicone resin sealing, and then clean the cementitious composite material; alternatively, directly clean the cementitious composite material; preferably, drying, UV resin sealing, penetrating primer, and silicone resin sealing are used before cleaning. The cleaning process generally uses a conventional surface vacuum cleaner, a dry cloth, etc. to remove surface moisture and dust, and atmospheric plasma treatment can be used to enhance its surface adhesion. Those skilled in the art can directly use a suitable surface cleaning and modification device according to specific needs; according to actual needs, the cementitious composite material is a cement board, a fiber calcium silicate board, a foamed ceiling gypsum board, or a glass magnesium board, and the product form is usually an insulation pipe, insulation board, partition board, ceiling board, or decorative board. The selection method is mainly to use cementitious base materials of different thicknesses and densities to meet different engineering needs, such as insulation, fire resistance, strength, hardness, etc. If necessary, low-density and high-thickness plates can be used according to special engineering cases to meet the needs of fire resistance, explosion resistance, and low-temperature resistance;

[0024] Step 2: Use resin-based continuous fiber fabric prepreg to three-dimensionally wrap the cementitious-based composite material, with the number of wrapping layers being 1-10 layers; the resin-based continuous fiber fabric prepreg is epoxy resin-based glass fiber fabric prepreg, epoxy resin-based carbon fiber fabric prepreg, unsaturated resin-based glass fiber fabric prepreg or unsaturated resin-based carbon fiber fabric prepreg. Those skilled in the art can directly use conventional prepregs purchased on the market or prepare various prepreg sheets by themselves according to specific needs; for the three-dimensional wrapping, a commercially available fiber resin-based wrapping and winding molding machine can be customized to achieve three-dimensional wrapping molding of various cementitious substrates. 1-10 layers of wrapping can be selected according to specific engineering requirements. If a low-cost alternative to organic glass fiber reinforced plastic parts (septic tanks) is required, 8-20 layers of prepreg wrapping molding can be selected; hand lay-up molding can also be selected as the winding molding method.

[0025] Step 3, hot pressing molding: placing the three-dimensionally wrapped gel-based composite material in a hot pressing curing machine or an autoclave for curing and molding. If a hot pressing curing machine is used, the process parameters are: preheating temperature of 60-100°C, preheating time of 20-100 minutes, hot pressing temperature of 120-150°C, hot pressing time of 60-180 minutes, and then naturally cooling or cooling to room temperature by water cooling to obtain a multifunctional high-performance gel-based composite material product; if an autoclave is used, the process parameters are: vacuuming from room temperature to -0.095MPa, heating to 70-80°C at 1-2°C / min, keeping warm for 50 minutes, then applying a pressure of 0.4-1MPa, heating to 120-140°C, keeping warm for 2-4 hours, cooling to 60°C and demolding to obtain a multifunctional high-performance gel-based composite material product.

[0026] The following describes two specific embodiments as examples.

[0027] Example 1:

[0028] The following steps are used to produce multifunctional, high-performance, gel-based composite calcium silicate boards:

[0029] Step 1: Use drying, UV resin sealing, penetrating primer and silicone resin sealing to seal the 8-12mm thick medium density (density 1.0-1.4g / cm 3 ) The gelled calcium silicate board is treated and then the surface is cleaned;

[0030] Step 2: Using epoxy resin-based carbon fiber fabric prepreg to three-dimensionally wrap the gel-based calcium silicate board, with the number of wrapping layers being 1-3;

[0031] Step 3: Place the wrapped gel-based calcium silicate board in a hot press curing machine, preheat the temperature to 65-90°C, preheat the time to 25-80 minutes, hot press the temperature to 120-145°C, hot press the time to 60-125 minutes, and then cool it naturally or with water to room temperature to obtain a multifunctional high-performance gel-based composite calcium silicate board finished product.

[0032] Example 2:

[0033] The following steps are used to produce multifunctional high-performance gelled composite glass magnesium board:

[0034] Step 1: Treat the 4-12mm thick gel-based glass magnesium board with drying, UV resin sealing, penetrating primer and silicone resin sealing, and then clean the surface;

[0035] Step 2: Using epoxy resin-based glass fiber fabric prepreg to three-dimensionally wrap the gel-based glass magnesium board, with the number of wrapping layers being 1-3;

[0036] Step 3: Place the wrapped gel-based glass magnesium board in a hot press curing machine with a preheating temperature of 80-100°C and a preheating time of 20-60 minutes, a hot pressing temperature of 130-150°C and a hot pressing time of 60-120 minutes, and then cool naturally or with water to room temperature to obtain a multifunctional high-performance gel-based composite glass magnesium board product.

[0037] The basic principle of the above two embodiments is to select polymer resin fiber prepreg to perform 3D wrapping on the gel-based calcium silicate board and the gel-based glass magnesium board respectively at room temperature, so as to achieve a high degree of dense contact between the prepreg and the gel-based board, and fix the surface of the gel-based calcium silicate board and the gel-based glass magnesium board with functional properties (thermal conductivity, electrical conductivity, etc.) and high strength fiber cloth to the surface of the gel-based calcium silicate board and the gel-based glass magnesium board. Subsequently, by laying multiple layers on the surface of the prepreg, the mechanical properties of the organic glass fiber reinforced plastic on the gel-based calcium silicate board and the gel-based glass magnesium board are greatly enhanced, and the mechanical properties can be adjusted by the number of laying layers; subsequently, the hot press curing machine is used for molding, and the high temperature and vacuum action can remove the gelling base, and the small molecules in the prepreg are volatilized, so as to achieve the stabilization of the service process of the gel-based composite board.

[0038] The inventors of the present invention conducted comparative experiments and found that conventional addition of short fibers (such as waste pulp fibers, imported coniferous fibers, microfibrillated fibers, plant fibers, and glass fibers) to cementitious composite materials containing solid waste (calcium silicate boards and glass magnesium boards) resulted in a flexural strength of only 15-20 MPa, even at a 20% short fiber loading. This performance is quite poor. Only by adding glass fiber mesh and non-woven fabrics can the flexural strength of the finished product reach 40 MPa. However, these glass fiber meshes and non-woven fabrics, when mixed during the cementitious composite molding process, are not suitable for fully cementitious products and are generally only suitable for the manufacture of glass magnesium boards and ordinary cement boards, lacking versatility.

[0039] The following tests compare the performance of the multifunctional high-performance cementitious composite calcium silicate board obtained in Example 1 above with that of a conventional cementitious calcium silicate board formed by mixing cement with 40% electric field tailings, 20% waste pulp fibers, and 40% cement. The results are as follows:

[0040] The mechanical properties were tested using a three-point bending method using a tensile compression material testing machine with a loading speed of 2 mm / min and a span of 64 mm. The results are as follows: Figure 1 As shown, the multifunctional high-performance gel-based composite calcium silicate board produced by the present invention has a flexural strength of up to 80-85 MPa, while the flexural strength of the conventional gel-based calcium silicate board is only about 15 MPa, which is a significant difference.

[0041] The resistance of conventional gel-based calcium silicate boards was tested using a high resistance meter, while the resistance of the multifunctional high-performance gel-based composite calcium silicate boards produced by the present invention was tested using a multimeter. The impact performance was tested using an impact tester with a simply supported 2J and 4J pendulum. The results of the above two tests are shown in the following table:

[0042] Surface resistance (Ω) <![CDATA[Impact (kJ / m 2 )]]> Conventional gel-based calcium silicate board 2.39 E+06 2.8 Multifunctional high performance gel-based composite calcium silicate board 8.6 24.5

[0043] The flame retardant performance test was carried out using the vertical combustion method, with a combustion time of 13 seconds and a total of 2 combustion times. The results are as follows: Figure 2As shown, the multifunctional high-performance gel-based composite calcium silicate board produced by the present invention had no open flame in both combustion tests, and the flame retardant grade reached V0; the conventional gel-based calcium silicate board had a small fire and was quickly extinguished in the first combustion test, and had no open flame in the second combustion test, and the flame retardant grade was V1.

[0044] In summary, after being laminated with epoxy resin-based carbon fiber fabric prepreg and cementitious calcium silicate board, the multifunctional, high-performance cementitious composite calcium silicate board exhibits a rich surface decorative effect, coupled with ultra-high flexural strength (85MPa), electrical conductivity, and impact toughness, making it suitable for use in electromagnetic shielding building materials. Furthermore, multifunctional, high-performance cementitious composite calcium silicate board is often used in fire-resistant and flame-retardant applications, achieving V0-level flame retardancy. Its performance far exceeds that of commercially available cementitious board materials, providing a new, versatile solution for enhancing, decorating, and functionalizing cementitious components containing solid waste, with excellent commercial value.

[0045] The above embodiments are only preferred embodiments of the present invention and are not limitations on the technical solutions of the present invention. Any technical solution that can be implemented on the basis of the above embodiments without creative work should be deemed to fall within the scope of protection of the patent of the present invention.

Claims

1. A method for preparing a multifunctional high-performance gel-based composite material, characterized by: The following steps are involved: Step 1: Treating the cementitious composite material by one or more of drying, UV resin sealing, penetrating primer, and silicone resin sealing, and then cleaning the cementitious composite material; or directly cleaning the cementitious composite material; Step 2: three-dimensionally wrapping the gel-based composite material with a resin-based continuous fiber fabric prepreg, with the number of wrapping layers being 1-10; Step 3, hot pressing molding: placing the three-dimensionally wrapped gel-based composite material in a hot pressing curing machine or an autoclave for curing and molding. If a hot pressing curing machine is used, the process parameters are: preheating temperature of 60-100°C, preheating time of 20-100 minutes, hot pressing temperature of 120-150°C, hot pressing time of 60-180 minutes, and then naturally cooling or cooling to room temperature by water cooling to obtain a multifunctional high-performance gel-based composite material product; if an autoclave is used, the process parameters are: vacuuming from room temperature to -0.095MPa, heating to 70-80°C at 1-2°C / min, keeping warm for 50 minutes, then applying a pressure of 0.4-1MPa, heating to 120-140°C, keeping warm for 2-4 hours, cooling to 60°C and demolding to obtain a multifunctional high-performance gel-based composite material product.

2. The method for preparing a multifunctional high-performance gel-based composite material according to claim 1, characterized in that: The gel-based composite material is a cement board, a fiber calcium silicate board, a foamed ceiling gypsum board or a glass magnesium board.

3. The method for preparing a multifunctional high-performance gel-based composite material according to claim 1 or 2, characterized in that: In the step 1, the gel-based composite material is treated by drying, UV resin sealing, penetrating primer and silicone resin sealing.

4. The method for preparing a multifunctional high-performance gel-based composite material according to claim 1 or 2, characterized in that: In step 2, the resin-based continuous fiber fabric prepreg is an epoxy resin-based glass fiber fabric prepreg, an epoxy resin-based carbon fiber fabric prepreg, an unsaturated resin-based glass fiber fabric prepreg, or an unsaturated resin-based carbon fiber fabric prepreg.

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