A high-temperature resistant and environmentally friendly household ceramic and its preparation method

Abstract

This invention discloses a high-temperature resistant and environmentally friendly household ceramic and its preparation method, relating to the field of ceramic technology. The ceramic is composed of the following components by weight: 12-24 parts kaolin, 6-12 parts alumina, 4-10 parts silicon dioxide, 4-7 parts magnesium oxide, 3-6 parts carbon fiber / boron nitride composite, 2-5 parts titanium dioxide, and 2-5 parts zirconium oxide. Through unique composite reinforcement technology and preparation process, this invention endows the ceramic with excellent comprehensive performance. The product as a whole has excellent mechanical strength, high temperature resistance, and outstanding thermal shock resistance, and can withstand severe thermal shock. Its structure is dense and uniform, and its performance is stable and reliable, significantly improving the overall quality of the product.

Description

Technical Field

[0001] This invention relates to the field of ceramic technology, specifically to a high-temperature resistant and environmentally friendly household ceramic and its preparation method. Background Technology

[0002] Ceramic materials are widely used in household applications such as tableware and cookware due to their chemical stability, high temperature resistance, high hardness, and non-toxicity. However, traditional household ceramics are mostly single-phase or simple multi-phase inorganic non-metallic materials, whose inherent brittleness and poor thermal shock resistance limit their application scenarios. For example, ordinary ceramic cookware is easily cracked and damaged by internal stress caused by the large temperature gradient when washed directly after being heated on a stovetop or heated immediately after being taken out of the refrigerator. In addition, bumps and knocks during daily use can easily cause ceramic products to chip or break, affecting their appearance and lifespan.

[0003] To improve the toughness and thermal shock resistance of ceramics, a major technological direction is to introduce reinforcing phases into the ceramic matrix to prepare ceramic matrix composites. Carbon fiber, due to its high strength, high modulus, low density, and excellent mechanical properties, is an ideal reinforcing and toughening agent. Hexagonal boron nitride, on the other hand, is known for its high thermal conductivity, low coefficient of thermal expansion, excellent chemical stability, and high-temperature lubricity, making it an ideal filler for improving the thermal shock resistance of materials. Theoretically, introducing both carbon fiber and boron nitride into the ceramic matrix is ​​expected to synergistically improve the overall performance of the ceramic.

[0004] CN105174968A discloses a high-hardness boron nitride ceramic and its preparation method, which is made from the following raw materials in parts by weight: boron nitride 85~115, alumina 1~6, kaolin powder 2~7, zirconium oxide powder 0.6~2, calcium oxide powder 1.5~4, titanium dioxide powder 2~6, antimony trioxide powder 1.5~3.5, carbon fiber 0.6~3, surfactant 0.05~0.3, polyethylene 0.5~3, anhydrous ethanol 20~30, glycerol 2~5, and deionized water 65~75.

[0005] However, this technical approach faces significant challenges in practical applications. First, the chemical inertness of carbon fiber surfaces results in extremely poor wettability and compatibility with inorganic ceramic matrices, leading to very weak interfacial bonding. Loads cannot be effectively transferred from the matrix to the fibers, significantly reducing the reinforcing effect of the fibers and even easily causing interfacial debonding, which becomes a source of material defects. Second, carbon fibers have a large specific surface area, making them prone to agglomeration. Uniform dispersion in ceramic matrices is difficult to achieve, and agglomerated fibers become stress concentration points, thus reducing the mechanical properties and reliability of the product. Third, during the high-temperature sintering process required for ceramics, carbon fibers are easily oxidized, causing their reinforcing effect to fail.

[0006] Therefore, how to effectively modify the surface of carbon fibers and boron nitride to construct a stable and strongly bonded interfacial transition layer, and achieve uniform dispersion of the reinforcement in the ceramic matrix, so as to give full play to its role in strengthening, toughening and improving thermal shock resistance, is a technical problem that urgently needs to be solved in the field of high-performance household ceramics. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a high-temperature resistant and environmentally friendly household ceramic and its preparation method. Through unique composite reinforcement technology and preparation process, the present invention endows the ceramic with excellent comprehensive performance. The product as a whole has excellent mechanical strength, high temperature resistance and outstanding thermal shock resistance, and can withstand severe thermal shock. Its structure is dense and uniform, and its performance is stable and reliable, significantly improving the overall quality of the product.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A high-temperature resistant and environmentally friendly household ceramic, by weight, is made of the following components: 12-24 parts kaolin, 6-12 parts alumina, 4-10 parts silicon dioxide, 4-7 parts magnesium oxide, 3-6 parts carbon fiber / boron nitride composite, 2-5 parts titanium dioxide, and 2-5 parts zirconium oxide.

[0010] Preferably, the carbon fiber / boron nitride composite material is prepared by the following method steps:

[0011] (1) Disperse carbon fibers in acetone, sonicate them, dry them and then disperse them in an aqueous solution of dopamine hydrochloride. Adjust the pH, stir the reaction, filter the product, wash it with water and dry it to obtain functionalized carbon fibers.

[0012] Preparation of functionalized carbon fibers: In a weakly alkaline aqueous solution, dopamine molecules undergo a series of reactions, including oxidation, intermolecular addition, and cross-linking, resulting in self-polymerization and the formation of an ultrathin and robust PDA film on the surface of the carbon fiber material. This film is rich in catechol hydroxyl and amine / imine groups, providing numerous active sites for subsequent grafting reactions.

[0013] Preferably, in step (1), the ratio of carbon fiber, acetone, and dopamine hydrochloride aqueous solution is 10g: 200~300mL: 400~600mL; the concentration of dopamine hydrochloride aqueous solution is 1~3mg / mL.

[0014] Preferably, in step (1), the ultrasonic treatment is performed for 30-60 min; the pH is adjusted to 8.0-9.0 with Tris buffer; and the stirring reaction is carried out at 20-35℃ for 12-24 h.

[0015] (2) Functionalized carbon fibers and monoepoxy POSS are dispersed in DMF, ultrasonically treated, stirred and reacted under nitrogen atmosphere, and the product is filtered, washed and dried to obtain modified carbon fibers.

[0016] Preparation of modified carbon fibers: On the PDA layer formed in the first step, a large number of amino groups... Acting as nucleophiles, they attack the epoxy ring on the monoepoxy POSS molecule, causing the epoxy ring to open and forming a stable carbon-nitrogen (CN) covalent bond, thus firmly "anchoring" the POSS molecule to the carbon fiber surface. At the same time, the ring-opening reaction also generates a new hydroxyl group nearby.

[0017] Preferably, in step (2), the ratio of functionalized carbon fiber, monoepoxy POSS, and DMF is 10g: 10~28g: 250~400mL.

[0018] Preferably, in step (2), the ultrasonic treatment is performed for 30~60 min; the stirring reaction conditions are 75~90℃ for 12~24 h.

[0019] (3) Boron nitride was ball-milled to obtain hydroxylated boron nitride, and then the hydroxylated boron nitride was dispersed in a polyacrylic acid ethanol solution, ultrasonically treated, and spray-dried to obtain modified boron nitride;

[0020] Preparation of modified boron nitride: First, defects and dangling bonds are created at the edges of the inert boron nitride (BN) lattice through the mechanochemical action of high-energy ball milling. These highly active sites react with water molecules in the air to form hydroxyl groups (-OH) on the BN surface. Subsequently, when the hydroxylated BN is dispersed in a polyacrylic acid (PAA) solution, multiple hydrogen bonds form between the hydroxyl groups on the BN surface and the numerous carboxyl groups (-COOH) on the PAA molecular chain. The final spray drying process rapidly removes the solvent, allowing the PAA to form a stable, carboxyl-rich outer shell through physical coating.

[0021] Preferably, in step (3), the ball milling conditions are: ball milling at 300~500 r / min for 12~36 h in a zirconia ball mill jar of a planetary ball mill; ultrasonic treatment time is 60~120 min; spray drying inlet temperature is 160~170℃ and outlet temperature is 70~80℃.

[0022] Preferably, in step (3), the ratio of hydroxylated boron nitride to polyacrylic acid ethanol solution is 10g: 250~400mL; the concentration of polyacrylic acid ethanol solution is 0.25~1wt%.

[0023] (4) The modified boron nitride was dispersed in DMF, ultrasonically treated, EDC and NHS were added, and the mixture was stirred and activated. Then the modified carbon fiber was added, and the mixture was stirred and reacted under a nitrogen atmosphere. The product was filtered, washed and dried to obtain carbon fiber / boron nitride composite material.

[0024] Preparation of composite materials: EDC, as a dehydrating agent, reacts with the carboxyl groups on the surface of modified boron nitride to form an O-acyl isourea intermediate, which is then captured by NHS to generate NHS active ester. The amino and hydroxyl groups on the surface of modified carbon fibers act as nucleophiles to attack this NHS active ester, forming amide bonds (-CO-NH-) and ester bonds (-CO-O-), thereby building a covalent bridge between carbon fibers and boron nitride and achieving a strong composite between the two.

[0025] Preferably, in step (4), the ratio of modified boron nitride, DMF, EDC, NHS and modified carbon fiber is 10g: 300~500mL: 2~5g: 1~3g: 3~6g; ultrasonic treatment for 30~60min; and stirring reaction conditions at 30~60℃ for 8~14h.

[0026] This invention also claims a method for preparing the aforementioned high-temperature resistant and environmentally friendly household ceramic, comprising the following steps: dispersing each component in ethanol, ultrasonically treating for 30-60 min to ensure uniform mixing, removing the ethanol, placing the mixture in a mold, pre-compacting it at 7.8-8.2 MPa for 10-12 s, and then cold-pressing it at 34-36 MPa for 7-9 min to obtain a ceramic green body; placing the ceramic green body in a sintering furnace, heating it to 860-900℃ at a rate of 6-7℃ / min under a nitrogen atmosphere, holding it at that temperature for 22-28 min, then heating it to 1550-1600℃ at a rate of 1.5-2.5℃ / min, holding it at that temperature for 2-3 h, and then naturally cooling it to obtain the aforementioned high-temperature resistant and environmentally friendly household ceramic.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. This invention provides a high-temperature resistant and environmentally friendly household ceramic. Kaolin serves as the basic framework, ensuring plasticity and formability. Alumina and silica, as the main temperature-resistant and reinforcing phases, endow the ceramic with excellent high-temperature structural stability and basic strength. Magnesium oxide, as a highly efficient flux, can reduce the sintering temperature and improve thermal shock resistance. Zirconia, through a phase transformation toughening mechanism, significantly improves the fracture toughness and strength of the ceramic. Carbon fiber / boron nitride composite material, as the core reinforcing phase, endows the ceramic with excellent mechanical properties and thermal shock resistance. Titanium dioxide gives the ceramic a clean and beautiful appearance and certain self-cleaning and environmentally friendly functions.

[0029] 2. This invention provides a carbon fiber / boron nitride composite material. First, polydopamine is coated onto the surface of the carbon fiber, which not only introduces a large number of active functional groups but also enhances the dispersion performance of the carbon fiber, avoiding defects caused by fiber agglomeration and improving the interfacial bonding between the fiber and the ceramic matrix. Second, the grafted polysilsesquioxane (POSS) will be converted in situ into [the desired product] during subsequent high-temperature sintering. Nano-ceramic structures such as SiC are tightly adhered to the surface of carbon fibers, forming a high-temperature resistant and oxidation-resistant "ceramic interface layer," which significantly improves the compressive strength and high-temperature stability of the carbon fibers. Finally, modified carbon fibers are cross-linked with modified boron nitride through chemical coupling, forming a stable three-dimensional cross-linked network structure at the microscopic level. This improves the homogeneity of the filler in the matrix, enabling it to act as a skeletal support during sintering and serving as an efficient pathway for stress transfer and heat conduction. Therefore, this design maximizes the excellent reinforcing and toughening effects of carbon fibers. In this composite material, carbon fibers contribute to the reinforcing and toughening effect, while boron nitride imparts thermal conductivity and thermal shock resistance to the ceramic. Ultimately, the comprehensive performance of the ceramic product in terms of toughness, strength, high-temperature oxidation resistance, and structural stability is comprehensively improved. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. Of course, the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention.

[0031] Unless otherwise specified, all chemical reagents and materials in this invention are purchased from the market or synthesized from raw materials purchased from the market.

[0032] Polyacrylic resin, purchased from Mitsubishi, Japan, brand name BR-116.

[0033] The general structural formula of monoepoxy group POSS is shown below:

[0034]

[0035] Wherein, R is one of isooctyl, isobutyl, or phenyl.

[0036] A method for preparing high-temperature resistant and environmentally friendly household ceramics includes the following steps:

[0037] (1) Disperse 10g of carbon fiber in 200-300mL of acetone, sonicate for 30-60min, dry and disperse in 400-600mL of 1-3mg / mL dopamine hydrochloride aqueous solution, adjust the pH to 8.0-9.0 with Tris buffer, stir and react at 20-35℃ for 12-24h, filter, wash with water and dry the product to obtain functionalized carbon fiber;

[0038] (2) Disperse 10g of functionalized carbon fiber and 10~28g of monoepoxy POSS into 250~400mL of DMF, sonicate for 30~60min, stir and react for 12~24h under nitrogen atmosphere at 75~90℃, filter, wash and dry the product to obtain modified carbon fiber.

[0039] (3) Boron nitride was ball-milled in a zirconium oxide ball mill jar of a planetary ball mill at 300-500 r / min for 12-36 h to obtain hydroxylated boron nitride. Then, 10 g of hydroxylated boron nitride was dispersed in 250-400 mL of 0.25-1 wt% polyacrylic acid ethanol solution, ultrasonically treated for 60-120 min, and spray-dried at an inlet temperature of 160-170 °C and an outlet temperature of 70-80 °C to obtain modified boron nitride.

[0040] (4) Disperse 10g of modified boron nitride in 300-500mL of DMF, sonicate for 30-60min, add 2-5g of EDC and 1-3g of NHS, stir to activate, then add 3-6g of modified carbon fiber, stir and react for 8-14h under nitrogen atmosphere at 30-60℃, filter, wash and dry the product to obtain carbon fiber / boron nitride composite material;

[0041] (5) Disperse 12-24 parts of kaolin, 6-12 parts of alumina, 4-10 parts of silicon dioxide, 4-7 parts of magnesium oxide, 3-6 parts of carbon fiber / boron nitride composite, 2-5 parts of titanium dioxide, and 2-5 parts of zirconium oxide into ethanol, sonicate for 30-60 min to mix evenly, evaporate the ethanol at 60°C to remove it, put the mixture into a mold, pre-tighten it at 7.8-8.2 MPa for 10-12 s, and then cold press it at 34-36 MPa for 7-9 min to obtain a ceramic green body; place the ceramic green body in a sintering furnace, heat it to 860-900°C at a rate of 6-7°C / min under a nitrogen atmosphere, hold it for 22-28 min, then heat it to 1550-1600°C at a rate of 1.5-2.5°C / min, hold it for 2-3 h, and cool it naturally to obtain the high-temperature resistant and environmentally friendly household ceramic.

[0042] The present invention will be further described below through specific embodiments. Example 1

[0043] A method for preparing high-temperature resistant and environmentally friendly household ceramics includes the following steps:

[0044] (1) 10g of carbon fiber was dispersed in 250mL of acetone, sonicated for 45min, dried and dispersed in 500mL of 2mg / mL dopamine hydrochloride aqueous solution, pH was adjusted to 8.5 with Tris buffer, and stirred at 35℃ for 12h. The product was filtered, washed with water and dried to obtain functionalized carbon fiber.

[0045] (2) 10g of functionalized carbon fiber and 28g of monoepoxy POSS were dispersed in 300mL of DMF, ultrasonically treated for 45min, and stirred at 90℃ in a nitrogen atmosphere for 12h. The product was filtered, washed and dried to obtain modified carbon fiber.

[0046] (3) Boron nitride was ball-milled in a zirconium oxide ball mill jar of a planetary ball mill at 400 r / min for 24 h to obtain hydroxylated boron nitride. Then, 10 g of hydroxylated boron nitride was dispersed in 300 mL of 0.5 wt% polyacrylic acid ethanol solution, ultrasonically treated for 90 min, and spray-dried at an inlet temperature of 165 °C and an outlet temperature of 75 °C to obtain modified boron nitride.

[0047] (4) Disperse 10g of modified boron nitride in 400mL of DMF, sonicate for 45min, add 5g of EDC and 3g of NHS, stir to activate, then add 6g of modified carbon fiber, stir and react for 8h under nitrogen atmosphere at 60℃, filter, wash and dry the product to obtain carbon fiber / boron nitride composite material.

[0048] (5) Disperse 2400g of kaolin, 1200g of alumina, 1000g of silicon dioxide, 700g of magnesium oxide, 600g of carbon fiber / boron nitride composite, 500g of titanium dioxide and 500g of zirconium oxide into 50L of ethanol, sonicate for 45min to mix evenly, evaporate the ethanol at 60℃, put the mixture into a mold, pre-tighten at 8.0MPa for 11s, and then cold press at 35MPa for 8min to obtain a ceramic green body; place the ceramic green body in a sintering furnace, heat it to 880℃ at a rate of 6.5℃ / min under a nitrogen atmosphere, hold it for 25min, then heat it to 1580℃ at a rate of 2.0℃ / min, hold it for 2.5h, and cool it naturally to obtain the high temperature resistant environmentally friendly household ceramic. Example 2

[0049] A method for preparing high-temperature resistant and environmentally friendly household ceramics includes the following steps:

[0050] (1) 10g of carbon fiber was dispersed in 250mL of acetone, sonicated for 45min, dried and dispersed in 500mL of 2mg / mL dopamine hydrochloride aqueous solution, pH was adjusted to 8.5 with Tris buffer, and stirred at 30℃ for 16h. The product was filtered, washed with water and dried to obtain functionalized carbon fiber.

[0051] (2) 10g of functionalized carbon fiber and 22g of monoepoxy POSS were dispersed in 300mL of DMF, ultrasonically treated for 45min, and stirred at 85℃ in a nitrogen atmosphere for 16h. The product was filtered, washed and dried to obtain modified carbon fiber.

[0052] (3) Boron nitride was ball-milled in a zirconium oxide ball mill jar of a planetary ball mill at 400 r / min for 24 h to obtain hydroxylated boron nitride. Then, 10 g of hydroxylated boron nitride was dispersed in 300 mL of 0.5 wt% polyacrylic acid ethanol solution, ultrasonically treated for 90 min, and spray-dried at an inlet temperature of 165 °C and an outlet temperature of 75 °C to obtain modified boron nitride.

[0053] (4) Disperse 10g of modified boron nitride in 400mL of DMF, sonicate for 45min, add 4g of EDC and 2g of NHS, stir to activate, then add 5g of modified carbon fiber, stir and react for 10h under nitrogen atmosphere at 50℃, filter, wash and dry the product to obtain carbon fiber / boron nitride composite material.

[0054] (5) Disperse 2000g of kaolin, 1000g of alumina, 800g of silicon dioxide, 600g of magnesium oxide, 500g of carbon fiber / boron nitride composite, 400g of titanium dioxide and 400g of zirconium oxide into 50L of ethanol, sonicate for 45min to mix evenly, evaporate the ethanol at 60℃, put the mixture into a mold, pre-tighten at 8.0MPa for 11s, and then cold press at 35MPa for 8min to obtain a ceramic green body; place the ceramic green body in a sintering furnace, heat it to 880℃ at a rate of 6.5℃ / min under a nitrogen atmosphere, hold it for 25min, then heat it to 1580℃ at a rate of 2.0℃ / min, hold it for 2.5h, and cool it naturally to obtain the high temperature resistant environmentally friendly household ceramic. Example 3

[0055] A method for preparing high-temperature resistant and environmentally friendly household ceramics includes the following steps:

[0056] (1) 10g of carbon fiber was dispersed in 250mL of acetone, ultrasonically treated for 45min, taken out and dried, and then dispersed in 500mL of 2mg / mL dopamine hydrochloride aqueous solution. The pH was adjusted to 8.5 with Tris buffer, and the reaction was stirred at 25℃ for 20h. The product was filtered, washed with water and dried to obtain functionalized carbon fiber.

[0057] (2) Disperse 10g of functionalized carbon fiber and 16g of monoepoxy POSS into 300mL of DMF, sonicate for 45min, stir and react for 20h at 80℃ under nitrogen atmosphere, filter, wash and dry the product to obtain modified carbon fiber.

[0058] (3) Boron nitride was ball-milled in a zirconium oxide ball mill jar of a planetary ball mill at 400 r / min for 24 h to obtain hydroxylated boron nitride. Then, 10 g of hydroxylated boron nitride was dispersed in 300 mL of 0.5 wt% polyacrylic acid ethanol solution, ultrasonically treated for 90 min, and spray-dried at an inlet temperature of 165 °C and an outlet temperature of 75 °C to obtain modified boron nitride.

[0059] (4) Disperse 10g of modified boron nitride in 400mL of DMF, sonicate for 45min, add 3g of EDC and 2g of NHS, stir to activate, then add 4g of modified carbon fiber, stir and react for 12h under nitrogen atmosphere at 40℃, filter, wash and dry the product to obtain carbon fiber / boron nitride composite material.

[0060] (5) Disperse 1600g of kaolin, 800g of alumina, 600g of silicon dioxide, 500g of magnesium oxide, 400g of carbon fiber / boron nitride composite, 300g of titanium dioxide and 300g of zirconium oxide into 50L of ethanol, sonicate for 45min to mix evenly, evaporate the ethanol at 60℃, put the mixture into a mold, pre-tighten at 8.0MPa for 11s, and then cold press at 35MPa for 8min to obtain a ceramic green body; place the ceramic green body in a sintering furnace, heat it to 880℃ at a rate of 6.5℃ / min under a nitrogen atmosphere, hold it for 25min, then heat it to 1580℃ at a rate of 2.0℃ / min, hold it for 2.5h, and cool it naturally to obtain the high temperature resistant environmentally friendly household ceramic. Example 4

[0061] A method for preparing high-temperature resistant and environmentally friendly household ceramics includes the following steps:

[0062] (1) 10g of carbon fiber was dispersed in 250mL of acetone, ultrasonically treated for 45min, taken out and dried, and then dispersed in 500mL of 2mg / mL dopamine hydrochloride aqueous solution. The pH was adjusted to 8.5 with Tris buffer, and the reaction was stirred at 20℃ for 24h. The product was filtered, washed with water and dried to obtain functionalized carbon fiber.

[0063] (2) 10g of functionalized carbon fiber and 28g of monoepoxy POSS were dispersed in 300mL of DMF, ultrasonically treated for 45min, and stirred at 90℃ in a nitrogen atmosphere for 12h. The product was filtered, washed and dried to obtain modified carbon fiber.

[0064] (3) Boron nitride was ball-milled in a zirconium oxide ball mill jar of a planetary ball mill at 400 r / min for 24 h to obtain hydroxylated boron nitride. Then, 10 g of hydroxylated boron nitride was dispersed in 300 mL of 0.5 wt% polyacrylic acid ethanol solution, ultrasonically treated for 90 min, and spray-dried at an inlet temperature of 165 °C and an outlet temperature of 75 °C to obtain modified boron nitride.

[0065] (4) Disperse 10g of modified boron nitride in 400mL of DMF, sonicate for 45min, add 2g of EDC and 1g of NHS, stir to activate, then add 3g of modified carbon fiber, stir and react for 14h under nitrogen atmosphere at 30℃, filter, wash and dry the product to obtain carbon fiber / boron nitride composite material.

[0066] (5) Disperse 1200g of kaolin, 600g of alumina, 400g of silicon dioxide, 400g of magnesium oxide, 300g of carbon fiber / boron nitride composite, 200g of titanium dioxide and 200g of zirconium oxide into 50L of ethanol, sonicate for 45min to mix evenly, evaporate the ethanol at 60℃, put the mixture into a mold, pre-tighten at 8.0MPa for 11s, and then cold press at 35MPa for 8min to obtain a ceramic green body; place the ceramic green body in a sintering furnace, heat it to 880℃ at a rate of 6.5℃ / min under a nitrogen atmosphere, hold it for 25min, then heat it to 1580℃ at a rate of 2.0℃ / min, hold it for 2.5h, and cool it naturally to obtain the high temperature resistant environmentally friendly household ceramic. Comparative Example 1

[0067] A method for preparing high-temperature resistant and environmentally friendly household ceramics includes the following steps:

[0068] (1) 10g of carbon fiber was dispersed in 250mL of acetone, sonicated for 45min, dried and dispersed in 500mL of 2mg / mL dopamine hydrochloride aqueous solution, pH was adjusted to 8.5 with Tris buffer, and stirred at 35℃ for 12h. The product was filtered, washed with water and dried to obtain functionalized carbon fiber.

[0069] (2) Boron nitride was ball-milled in a zirconium oxide ball mill jar of a planetary ball mill at 400 r / min for 24 h to obtain hydroxylated boron nitride. Then, 10 g of hydroxylated boron nitride was dispersed in 300 mL of 0.5 wt% polyacrylic acid ethanol solution, ultrasonically treated for 90 min, and spray-dried at an inlet temperature of 165 °C and an outlet temperature of 75 °C to obtain modified boron nitride.

[0070] (3) Disperse 10g of modified boron nitride in 400mL of DMF, sonicate for 45min, add 5g of EDC and 3g of NHS, stir to activate, then add 6g of functionalized carbon fiber, stir and react for 8h under nitrogen atmosphere at 60℃, filter, wash and dry the product to obtain carbon fiber / boron nitride composite.

[0071] (4) Disperse 2400g of kaolin, 1200g of alumina, 1000g of silicon dioxide, 700g of magnesium oxide, 600g of carbon fiber / boron nitride composite, 500g of titanium dioxide and 500g of zirconium oxide into 50L of ethanol, sonicate for 45min to mix evenly, evaporate the ethanol at 60℃, put the mixture into a mold, pre-tighten at 8.0MPa for 11s, and then cold press at 35MPa for 8min to obtain a ceramic green body; place the ceramic green body in a sintering furnace, heat it to 880℃ at a rate of 6.5℃ / min under a nitrogen atmosphere, hold it for 25min, then heat it to 1580℃ at a rate of 2.0℃ / min, hold it for 2.5h, and cool it naturally to obtain the high temperature resistant and environmentally friendly household ceramic. Comparative Example 2

[0072] A method for preparing high-temperature resistant and environmentally friendly household ceramics includes the following steps:

[0073] (1) 10g of carbon fiber was dispersed in 250mL of acetone, sonicated for 45min, dried and dispersed in 500mL of 2mg / mL dopamine hydrochloride aqueous solution, pH was adjusted to 8.5 with Tris buffer, and stirred at 35℃ for 12h. The product was filtered, washed with water and dried to obtain functionalized carbon fiber.

[0074] (2) 10g of functionalized carbon fiber and 28g of monoepoxy POSS were dispersed in 300mL of DMF, ultrasonically treated for 45min, and stirred at 90℃ in a nitrogen atmosphere for 12h. The product was filtered, washed and dried to obtain modified carbon fiber.

[0075] (3) Boron nitride was ball-milled in a zirconium oxide ball mill jar of a planetary ball mill at 400 r / min for 24 h to obtain hydroxylated boron nitride;

[0076] (4) Disperse 2400g of kaolin, 1200g of alumina, 1000g of silicon dioxide, 700g of magnesium oxide, 375g of hydroxylated boron nitride, 225g of modified carbon fiber, 500g of titanium dioxide and 500g of zirconium oxide into 50L of ethanol, sonicate for 45min to mix evenly, evaporate ethanol at 60℃ to remove the ethanol, put the mixture into a mold, pre-tighten at 8.0MPa for 11s, and then cold press at 35MPa for 8min to obtain a ceramic green body; place the ceramic green body in a sintering furnace, heat it to 880℃ at a rate of 6.5℃ / min under a nitrogen atmosphere, hold it for 25min, then heat it to 1580℃ at a rate of 2.0℃ / min, hold it for 2.5h, and cool it naturally to obtain the high temperature resistant environmentally friendly household ceramic. Comparative Example 3

[0077] A method for preparing high-temperature resistant and environmentally friendly household ceramics includes the following steps:

[0078] (1) 10g of carbon fiber was dispersed in 250mL of acetone, sonicated for 45min, dried and dispersed in 500mL of 2mg / mL dopamine hydrochloride aqueous solution, pH was adjusted to 8.5 with Tris buffer, and stirred at 35℃ for 12h. The product was filtered, washed with water and dried to obtain functionalized carbon fiber.

[0079] (2) Boron nitride was ball-milled in a zirconium oxide ball mill jar of a planetary ball mill at 400 r / min for 24 h to obtain hydroxylated boron nitride;

[0080] (3) Disperse 2400g of kaolin, 1200g of alumina, 1000g of silicon dioxide, 700g of magnesium oxide, 375g of hydroxylated boron nitride, 225g of functionalized carbon fiber, 500g of titanium dioxide and 500g of zirconium oxide into 50L of ethanol, sonicate for 45min to mix evenly, evaporate ethanol at 60℃ to remove the ethanol, put the mixture into a mold, pre-tighten at 8.0MPa for 11s, and then cold press at 35MPa for 8min to obtain a ceramic green body; place the ceramic green body in a sintering furnace, heat it to 880℃ at a rate of 6.5℃ / min under a nitrogen atmosphere, hold it for 25min, then heat it to 1580℃ at a rate of 2.0℃ / min, hold it for 2.5h, and cool it naturally to obtain the high temperature resistant and environmentally friendly household ceramic.

[0081] In the example: carbon fiber was modified with dopamine to obtain functionalized carbon fiber, and then grafted with monoepoxy POSS to obtain modified carbon fiber; boron nitride was ball-milled to obtain hydroxylated boron nitride, and then modified with polyacrylic acid to obtain modified boron nitride; modified boron nitride was compounded with modified carbon fiber to obtain carbon fiber / boron nitride composite; finally, carbon fiber / boron nitride composite was added to a ceramic matrix.

[0082] In Comparative Example 1: carbon fibers were modified with dopamine to obtain functionalized carbon fibers; boron nitride was ball-milled to obtain hydroxylated boron nitride, which was then modified with polyacrylic acid to obtain modified boron nitride; the modified boron nitride was then combined with functionalized carbon fibers to obtain a carbon fiber / boron nitride composite; finally, the carbon fiber / boron nitride composite was added to a ceramic matrix. The difference from the examples is that the functionalized carbon fibers were not modified with monoepoxy group POSS.

[0083] In Comparative Example 2: carbon fibers were modified with dopamine to obtain functionalized carbon fibers, which were then grafted with monoepoxy POSS to obtain modified carbon fibers; boron nitride was ball-milled to obtain hydroxylated boron nitride; and modified carbon fibers and hydroxylated boron nitride were directly added to a ceramic matrix. The difference from the examples is that the hydroxylated boron nitride was not modified with polyacrylic acid (therefore it could not be compounded with modified carbon fibers).

[0084] In Comparative Example 3: carbon fibers were modified with dopamine to obtain functionalized carbon fibers; boron nitride was ball-milled to obtain hydroxylated boron nitride; and functionalized carbon fibers and hydroxylated boron nitride were directly added to a ceramic matrix. The difference from the Examples is that the functionalized carbon fibers and hydroxylated boron nitride were not modified.

[0085] The ceramics prepared in Examples 1-4 and Comparative Examples 1-3 were subjected to performance tests. The gloss, lead leaching, and chromium leaching of the ceramics were tested according to GB / T 3532-2022 "Daily-use Porcelain". The thermal shock resistance of the ceramics was tested according to GB / T 3298-2022 "Determination of Thermal Shock Resistance of Daily-use Ceramics", using a 20°C temperature gradient. The difference between the highest heating temperature at which the sample did not break and the room temperature water temperature (20°C) was recorded as an indicator of its thermal shock resistance, in °C, and the average value of 5 samples was taken. The total number of "pressure-heating" cycles that each sample could withstand before the first glaze crack appeared was recorded according to GB / T 34252-2017 "Test Method for Glaze Crack Resistance of Daily-use Ceramics", and the crack resistance index was taken as the average value of 5 samples. The fracture toughness was tested according to GB / T 23806-2009 "Test Method for Fracture Toughness of Fine Ceramics - Single-sided Pre-cracked Beam (SEPB) Method". The fracture toughness was also tested according to GB / T... The tensile strength was tested according to GB / T 23805-2009, "Test Method for Tensile Strength of Fine Ceramics at Room Temperature". Specific data are shown in Table 1.

[0086] Table 1 Ceramic performance test results

[0087]

[0088] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A high-temperature resistant and environmentally friendly household ceramic, characterized in that, It is made of the following components by weight: 12-24 parts kaolin, 6-12 parts alumina, 4-10 parts silicon dioxide, 4-7 parts magnesium oxide, 3-6 parts carbon fiber / boron nitride composite, 2-5 parts titanium dioxide, and 2-5 parts zirconium oxide. The carbon fiber / boron nitride composite material is prepared by the following steps: (1) Disperse carbon fibers in acetone, sonicate them, dry them and then disperse them in an aqueous solution of dopamine hydrochloride. Adjust the pH, stir the reaction, filter the product, wash it with water and dry it to obtain functionalized carbon fibers. (2) Functionalized carbon fibers and monoepoxy POSS are dispersed in DMF, ultrasonically treated, stirred and reacted under nitrogen atmosphere, and the product is filtered, washed and dried to obtain modified carbon fibers. (3) Boron nitride was ball-milled to obtain hydroxylated boron nitride, and then the hydroxylated boron nitride was dispersed in a polyacrylic acid ethanol solution, ultrasonically treated, and spray-dried to obtain modified boron nitride; (4) The modified boron nitride was dispersed in DMF, ultrasonically treated, EDC and NHS were added, and the mixture was stirred and activated. Then the modified carbon fiber was added, and the mixture was stirred and reacted under a nitrogen atmosphere. The product was filtered, washed and dried to obtain carbon fiber / boron nitride composite material.

2. The high-temperature resistant and environmentally friendly household ceramic according to claim 1, characterized in that, In step (1), the ratio of carbon fiber, acetone, and dopamine hydrochloride aqueous solution is 10g: 200~300mL: 400~600mL; the concentration of dopamine hydrochloride aqueous solution is 1~3mg / mL.

3. The high-temperature resistant and environmentally friendly household ceramic according to claim 1, characterized in that, In step (1), the ultrasonic treatment lasts for 30-60 min; the pH is adjusted to 8.0-9.0 with Tris buffer; and the stirring reaction is carried out at 20-35℃ for 12-24 h.

4. The high-temperature resistant and environmentally friendly household ceramic according to claim 1, characterized in that, In step (2), the ratio of functionalized carbon fiber, monoepoxy POSS, and DMF is 10g: 10~28g: 250~400mL.

5. The high-temperature resistant and environmentally friendly household ceramic according to claim 1, characterized in that, In step (2), the ultrasonic treatment lasts for 30 to 60 minutes; the stirring reaction conditions are 75 to 90°C for 12 to 24 hours.

6. The high-temperature resistant and environmentally friendly household ceramic according to claim 1, characterized in that, In step (3), the ball milling conditions are as follows: ball milling at 300~500 r / min for 12~36 h in a zirconia ball mill jar of a planetary ball mill; ultrasonic treatment time is 60~120 min; spray drying inlet temperature is 160~170℃ and outlet temperature is 70~80℃.

7. The high-temperature resistant and environmentally friendly household ceramic according to claim 1, characterized in that, In step (3), the ratio of hydroxylated boron nitride to polyacrylic acid ethanol solution is 10g: 250~400mL; the concentration of polyacrylic acid ethanol solution is 0.25~1wt%.

8. The high-temperature resistant and environmentally friendly household ceramic according to claim 1, characterized in that, In step (4), the ratio of modified boron nitride, DMF, EDC, NHS and modified carbon fiber is 10g: 300~500mL: 2~5g: 1~3g: 3~6g; ultrasonic treatment for 30~60min; stirring reaction conditions are 30~60℃ for 8~14h.

9. A method for preparing high-temperature resistant and environmentally friendly household ceramics as described in any one of claims 1 to 8, characterized in that, The process includes the following steps: dispersing each component in ethanol, ultrasonically treating for 30-60 minutes to ensure uniform mixing, removing the ethanol, placing the mixture in a mold, pre-compacting it at 7.8-8.2 MPa for 10-12 seconds, and then cold-pressing it at 34-36 MPa for 7-9 minutes to obtain a ceramic green body; placing the ceramic green body in a sintering furnace, heating it to 860-900℃ at a rate of 6-7℃ / min under a nitrogen atmosphere, holding it at that temperature for 22-28 minutes, then heating it to 1550-1600℃ at a rate of 1.5-2.5℃ / min, holding it at that temperature for 2-3 hours, and then naturally cooling it to obtain the high-temperature resistant and environmentally friendly household ceramic.

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