High-strength environment-friendly ceramic and preparation method thereof

Abstract

This invention discloses a high-strength environmentally friendly ceramic and its preparation method, relating to the field of environmentally friendly ceramic technology. The high-strength environmentally friendly ceramic comprises the following raw materials in parts by weight: 20-40 parts diatomaceous earth, 15-30 parts albite, 5-15 parts talc, 3-10 parts pore-forming agent, and 1-5 parts modifier. In this invention, intermediate 1 is generated by reacting 4,4'-dithiodibutyric acid with epichlorohydrin; intermediate 1 is then reacted with 4-(1,3-dioxo-1,3,3A,4,7,7A-hexahydro-2H-4,7-methoxyisoindole-2-yl)benzoic acid to generate intermediate 2; intermediate 2 is further reacted with 3-aminopropyltrimethoxysilane to generate intermediate 3; and intermediate 3 is then reacted with 5-chloro-1,2,3-benzenetricarboxylic acid to generate the modifier. The high-strength environmentally friendly ceramic prepared by this invention exhibits excellent mechanical properties and thermal insulation performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of environment-friendly ceramics, and particularly relates to a high-strength environment-friendly ceramic and a preparation method thereof. BACKGROUND

[0002] With the deepening of the "double carbon" strategy, developing new ceramic materials with high performance and low environmental load has become a trend in the industry. Ceramic materials play an important role due to their durability and fire resistance. However, the production process of traditional ceramics is often not environmentally friendly, and the performance of the products often has a conflict between mechanical strength and thermal insulation, for example, the high porosity of ceramics often reduces its mechanical strength, making it difficult to achieve a balance between high strength and high porosity. Therefore, environment-friendly ceramics with high strength and excellent thermal insulation performance have gradually become the ideal choice in the market. Although it has been recognized in the industry that using natural minerals such as diatomite is an important way to improve the environmental performance of ceramics, there are still some technical difficulties. For example, diatomite itself has a natural microporous structure, which is an ideal raw material for giving ceramics lightweight thermal insulation function, but the introduction of diatomite often deteriorates the mechanical strength of the material. Therefore, it is of great significance to develop a ceramic material with both environmental protection and high strength.

[0003] A Chinese invention patent with publication number CN118878313A discloses a daily-use high-strength environment-friendly ceramic and a preparation process thereof, which comprises the following raw materials by weight: 30-35 parts of potassium feldspar, 10-15 parts of sodium feldspar, 10-15 parts of spodumene, 8-12 parts of doping bentonite modifier, 8-10 parts of mullite, 8-12 parts of chitosan modifier, 2-5 parts of nano-zinc oxide, and 2-5 parts of nano-silver powder. The environment-friendly ceramic of the invention uses potassium feldspar, sodium feldspar, spodumene, and mullite as raw materials, and cooperates with nano-zinc oxide and nano-silver powder to optimize the antibacterial performance of the product. The doping of bentonite modifier and chitosan modifier can improve the strength and cleaning performance of the product, and the antibacterial durability of the product is significantly improved. However, the thermal insulation performance of the product is still insufficient. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application aims to provide a high-strength environment-friendly ceramic and a preparation method thereof.

[0005] To achieve the above-mentioned purpose, the present application realizes the following technical solutions:

[0006] A high-strength environment-friendly ceramic comprises the following raw materials by weight:

[0007] 20-40 parts of diatomite, 15-30 parts of sodium feldspar, 5-15 parts of talc powder, 3-10 parts of pore-forming agent, and 1-5 parts of modifier;

[0008] The modifier is prepared by the following method:

[0009] S1: 4,4'-Dithiodibutyric acid reacts with epichlorohydrin to generate intermediate 1, and the reaction equation is shown below:

[0010]

[0011] S2: Intermediate 1 reacts with 4-(1,3-dioxo-1,3,3A,4,7,7A-hexahydro-2H-4,7-methoxyisoindole-2-yl)benzoic acid to generate intermediate 2, and the reaction equation is shown below:

[0012]

[0013] S3: Intermediate 2 reacts with 3-aminopropyltrimethoxysilane to generate intermediate 3, and the reaction equation is shown below:

[0014]

[0015] S4: Intermediate 3 reacts with 5-chloro-1,2,3-benzenetricarboxylic acid to generate a modifier, and the reaction equation is shown below:

[0016]

[0017] In step S1, the molar ratio of 4,4'-dithiodibutyric acid to epichlorohydrin is 1:(2.01-2.05).

[0018] In step S2, the molar ratio of intermediate 1 to 4-(1,3-dioxo-1,3,3A,4,7,7A-hexahydro-2H-4,7-methoxyisoindole-2-yl)benzoic acid is 1:(2.1-2.2).

[0019] In step S3, the molar ratio of intermediate 2 to 3-aminopropyltrimethoxysilane is 1:(2.01-2.05).

[0020] In step S4, the molar ratio of intermediate 3 to 5-chloro-1,2,3-benzenetricarboxylic acid is 1:(2.1-2.3).

[0021] The reaction temperature for step S1 is 80-90℃ and the reaction time is 1.5-2.5h; the reaction temperature for step S2 is 25-30℃ and the reaction time is 8-9h.

[0022] The reaction temperature for step S3 is 50-60℃ and the reaction time is 6-8h; the reaction temperature for step S4 is 110-120℃ and the reaction time is 12-14h.

[0023] The reaction solvent in step S1 is anhydrous toluene; the reaction solvent in step S2 is anhydrous DMF; the reaction solvent in step S3 is anhydrous tetrahydrofuran; and the reaction solvent in step S4 is anhydrous DMF.

[0024] The pore-forming agent is ammonium bicarbonate.

[0025] A method for preparing high-strength environmentally friendly ceramics includes the following steps:

[0026] (1) Weigh out the following by weight: 20-40 parts diatomaceous earth, 15-30 parts sodium feldspar, 5-15 parts talc, 3-10 parts pore-forming agent, and 1-5 parts modifier.

[0027] (2) Mix the above raw materials and put them into a planetary ball mill. Add anhydrous ethanol and ball mill to obtain a slurry. After drying, obtain a powder.

[0028] (3) Grind the powder and put it into a mold, press it into shape, and obtain the blank;

[0029] (4) The green body is hot-pressed and sintered, and then cooled to obtain high-strength environmentally friendly ceramics.

[0030] Due to the adoption of the above technical solutions, the beneficial effects of the present invention include:

[0031] The high-strength environmentally friendly ceramic prepared by this invention has a high apparent porosity and achieves a low thermal conductivity. Furthermore, this application achieves high compressive strength with a high apparent porosity, exhibiting good mechanical properties and thermal insulation performance. The added modifier contains disulfide bonds, benzene rings, siloxane structures, norbornene structures, and multiple carboxyl groups. The synergistic effect of these structures improves the mechanical properties and thermal insulation performance of the ceramic. Detailed Implementation

[0032] The following description, in conjunction with specific embodiments, provides further details, but the present invention is not limited to these embodiments.

[0033] Example 1: Preparation of the modifier:

[0034] S1: Under nitrogen protection, 200 ml of anhydrous toluene and 0.1 mol of 4,4'-dithiodibutyric acid were stirred and mixed. 0.201 mol of epichlorohydrin was slowly added dropwise over 30 min. After the addition was complete, 0.021 mol of tetraethylammonium bromide and 0.21 mol of K₂CO₃ were added. The mixture was heated to 80 °C and reacted for 2.5 h. After cooling to room temperature, the mixture was distilled under reduced pressure at 70 °C for 2 h. 200 ml of cold n-hexane was added and stirred to precipitate the precipitate. The precipitate was filtered, washed with cold n-hexane (3 × 50 ml), and dried under vacuum at 60 °C for 8 h to obtain intermediate 1. Its 1H NMR data are as follows: 1 HNMR (400 MHz, Chloroform- d) δ 4.25-4.18 (m, 4H), 4.15 (d, J = 12.4 Hz, 2H), 3.85 (d, J = 5.0 Hz, 2H), 3.72 (d, J = 3.2 Hz, 4H), 2.74 (s, 4H), 2.42 (d, J= 3.5 Hz, 4H), 1.94 (d, J = 2.8 Hz, 4H);

[0035] S2: Under nitrogen protection and in an ice bath, add 700 ml of anhydrous DMF, 0.21 mol of 4-(1,3-dioxo-1,3,3A,4,7,7A-hexahydro-2H-4,7-methoxyisoindole-2-yl)benzoic acid, 50.42 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 30.36 g of... N-hydroxysuccinimide was mixed and stirred for 45 min to obtain an activated DMF solution of 4-(1,3-dioxo-1,3,3A,4,7,7A-hexahydro-2H-4,7-methoxyisoindole-2-yl)benzoic acid. The activated DMF solution of 4-(1,3-dioxo-1,3,3A,4,7,7A-hexahydro-2H-4,7-methoxyisoindole-2-yl)benzoic acid was slowly added dropwise to 200 mL of anhydrous DMF solution containing 0.1 mol of intermediate 1. The addition was completed over 3 h, and the reaction was carried out at 25 °C for 9 h (using 0.1 M...). The solution was maintained at pH 5-5.5 using HCl / NaOH solution. The mixture was filtered, and the filtrate was slowly poured into 1000 ml of cold n-hexane with stirring to precipitate the solid. The precipitate was then filtered, and the filter cake was washed with 3 × 50 ml of cold n-hexane and dried under vacuum at 70 °C for 12 h to obtain intermediate 2. Its 1H NMR data are as follows: 1 H NMR (400 MHz, Chloroform- d ) δ 8.05-7.97 (m, 4H), 7.36-7.29 (m, 4H), 6.17 (s, 4H), 5.21 (s, 2H), 4.48-4.35 (m, 4H), 3.93-3.81 (m, 4H), 3.38 (d, J= 3.4 Hz, 8H), 2.74 (s, 4H), 2.42 (d, J = 1.9 Hz, 4H), 1.94 (d, J = 2.7 Hz, 4H), 1.75-1.55 (m, 4H);

[0036] S3: Under nitrogen protection, 750 ml of anhydrous tetrahydrofuran, 0.1 mol of intermediate 2, and 0.201 mol of 3-aminopropyltrimethoxysilane were stirred and mixed. 0.21 mol of triethylamine was added, and the mixture was heated to 50 °C and reacted for 8 h. After cooling to room temperature, the mixture was filtered. 800 ml of cold anhydrous n-hexane was added to the filtrate and stirred to precipitate the solid. The precipitate was filtered, and the filter cake was washed with cold anhydrous n-hexane (3 × 50 ml). The precipitate was dried under vacuum at 50 °C for 8 h to obtain intermediate 3. Its 1H NMR data are as follows: 1 H NMR (400 MHz, Chloroform- d ) δ8.05-7.97 (m, 4H), 7.36-7.29 (m, 4H), 6.17 (s, 4H), 4.87 (s, 2H), 4.41-4.26(m, 4H), 3.57 (s, 18H), 3.53 (t, J = 0.5 Hz, 2H), 3.38 (d, J = 3.4 Hz, 8H), 3.03-2.92 (m, 4H), 2.91-2.76 (m, 4H), 2.74 (s, 4H), 2.42 (d, J = 1.9 Hz, 4H), 1.94 (d, J = 2.7 Hz, 4H), 1.76-1.55 (m, 8H), 1.13-1.00 (m, 4H);

[0037] S4: Under nitrogen protection, 900 ml of anhydrous DMF, 0.1 mol of intermediate 3, and 0.21 mol of 5-chloro-1,2,3-benzenetricarboxylic acid were stirred and mixed. 3 mmol of Pd(OAc)₂, 3.2 mmol of RuPhos, and 0.2 mol of K₃PO₄ were added, and the mixture was heated to 110 °C and reacted for 14 h. After cooling to room temperature, 800 ml of anhydrous toluene was added to the reaction mixture, and the mixture was stirred thoroughly. The mixture was filtered, and the filtrate was concentrated under reduced pressure at 70 °C for 1 h to obtain a concentrated solution. 500 ml of anhydrous ethyl acetate and 30 g of anhydrous potassium carbonate were added to the concentrated solution, and the mixture was stirred for 1 h. After filtration, the solution was dried over 35 g of anhydrous magnesium sulfate for 2 h, filtered again, and distilled under reduced pressure at 45 °C for 2 h to obtain the crude product. The crude product was purified by silica gel column chromatography (petroleum ether / ethyl acetate V / V = 1:4) and distilled under reduced pressure at 40 °C for 5 h to obtain the modifier. Its 1H NMR data are as follows: 1 H NMR (400 MHz, Chloroform- d) δ 12.63 (s, 2H), 12.52 (s, 4H), 8.05-7.97 (m, 4H), 7.58 (s,4H), 7.36-7.29 (m, 4H), 6.17 (s, 4H), 5.01 (s, 2H), 4.48-4.31 (m, 4H), 3.57(s, 18H), 3.56-3.43 (m, 4H), 3.38 (d, J = 3.4 Hz, 8H), 3.34-3.25 (m, 4H), 2.74 (s, 4H), 2.42 (d, J = 1.9 Hz, 4H), 1.94 (d, J = 2.7 Hz, 4H), 1.80-1.54(m, 8H), 1.15(s, 4H).

[0038] Example 2: Preparation of the modifier:

[0039] S1: Under nitrogen protection, 200 ml of anhydrous toluene and 0.1 mol of 4,4'-dithiodibutyric acid were stirred and mixed. 0.203 mol of epichlorohydrin was slowly added dropwise. After the addition was completed in 30 min, 0.021 mol of tetraethylammonium bromide and 0.21 mol of K2CO3 were added. The mixture was heated to 85 °C and reacted for 2 h. After cooling to room temperature, the mixture was distilled under reduced pressure at 70 °C for 2 h. 200 ml of cold n-hexane was added and stirred to precipitate the precipitate. The precipitate was filtered, washed with cold n-hexane (3 × 50 ml), and dried under vacuum at 60 °C for 8 h to obtain intermediate 1.

[0040] S2: Under nitrogen protection and in an ice bath, 700 ml of anhydrous DMF, 0.215 mol of 4-(1,3-dioxo-1,3,3A,4,7,7A-hexahydro-2H-4,7-methoxyisoindole-2-yl)benzoic acid, 50.42 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 30.36 g of... N-hydroxysuccinimide was mixed and stirred for 45 min to obtain an activated DMF solution of 4-(1,3-dioxo-1,3,3A,4,7,7A-hexahydro-2H-4,7-methoxyisoindole-2-yl)benzoic acid. The activated DMF solution of 4-(1,3-dioxo-1,3,3A,4,7,7A-hexahydro-2H-4,7-methoxyisoindole-2-yl)benzoic acid was slowly added dropwise to 200 ml of anhydrous DMF solution containing 0.1 mol of intermediate 1. The addition was completed in 3 h, and the reaction was carried out at 25 °C for 9 h (the pH of the solution was maintained between 5 and 5.5 during the reaction with 0.1 M HCl / NaOH solution). The mixture was filtered, and the filtrate was slowly poured into 1000 ml of cold n-hexane and stirred to precipitate the precipitate. The precipitate was filtered, and the filter cake was washed with cold n-hexane (3 × 50 ml) and dried under vacuum at 70 °C for 12 h to obtain intermediate 2.

[0041] S3: Under nitrogen protection, 750 ml of anhydrous tetrahydrofuran, 0.1 mol of intermediate 2, and 0.203 mol of 3-aminopropyltrimethoxysilane were stirred and mixed. 0.21 mol of triethylamine was added, and the mixture was heated to 55 °C and reacted for 7 h. After cooling to room temperature, the mixture was filtered. 800 ml of cold anhydrous n-hexane was added to the filtrate and stirred to precipitate the precipitate. The precipitate was filtered, and the filter cake was washed with cold anhydrous n-hexane (3 × 50 ml). The mixture was then dried under vacuum at 50 °C for 8 h to obtain intermediate 3.

[0042] S4: Under nitrogen protection, 900 ml of anhydrous DMF, 0.1 mol of intermediate 3, and 0.22 mol of 5-chloro-1,2,3-benzenetricarboxylic acid were stirred and mixed. 3 mmol of Pd(OAc)2, 3.2 mmol of RuPhos, and 0.2 mol of K3PO4 were added, and the mixture was heated to 115 °C and reacted for 13 h. After cooling to room temperature, 800 ml of anhydrous toluene was added to the reaction solution, and the mixture was stirred thoroughly. The solution was filtered, and the filtrate was concentrated under reduced pressure at 70 °C for 1 h to obtain a concentrated solution. 500 ml of anhydrous ethyl acetate and 30 g of anhydrous potassium carbonate were added to the concentrated solution, and the mixture was stirred for 1 h. The solution was filtered, dried over 40 g of anhydrous magnesium sulfate for 2 h, filtered again, and distilled under reduced pressure at 45 °C for 2 h to obtain the crude product. The crude product was purified by silica gel column chromatography (petroleum ether / ethyl acetate V / V = 1:4) and distilled under reduced pressure at 40 °C for 5 h to obtain the modifier.

[0043] Example 3: Preparation of the modifier:

[0044] S1: Under nitrogen protection, 200 ml of anhydrous toluene and 0.1 mol of 4,4'-dithiodibutyric acid were stirred and mixed. 0.205 mol of epichlorohydrin was slowly added dropwise. After the addition was completed in 30 min, 0.021 mol of tetraethylammonium bromide and 0.21 mol of K2CO3 were added. The mixture was heated to 90 °C and reacted for 1.5 h. After cooling to room temperature, the mixture was distilled under reduced pressure at 70 °C for 2 h. 200 ml of cold n-hexane was added and stirred to precipitate the precipitate. The precipitate was filtered, washed with cold n-hexane (3 × 50 ml), and dried under vacuum at 60 °C for 8 h to obtain intermediate 1.

[0045] S2: Under nitrogen protection and in an ice bath, mix 700 ml of anhydrous DMF, 0.22 mol of 4-(1,3-dioxo-1,3,3A,4,7,7A-hexahydro-2H-4,7-methoxyisoindole-2-yl)benzoic acid, 50.42 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and 30.36 g of... N-hydroxysuccinimide was mixed and stirred for 45 min to obtain an activated DMF solution of 4-(1,3-dioxo-1,3,3A,4,7,7A-hexahydro-2H-4,7-methoxyisoindole-2-yl)benzoic acid. The activated DMF solution of 4-(1,3-dioxo-1,3,3A,4,7,7A-hexahydro-2H-4,7-methoxyisoindole-2-yl)benzoic acid was slowly added dropwise to 200 ml of anhydrous DMF solution containing 0.1 mol of intermediate 1 over 3 h. The reaction was carried out at 30 °C for 8 h (the pH of the solution was maintained between 5 and 5.5 during the reaction with 0.1 M HCl / NaOH solution). The solution was filtered, and the filtrate was slowly poured into 1000 ml of cold n-hexane and stirred to precipitate the precipitate. The precipitate was filtered, and the filter cake was washed with cold n-hexane (3 × 50 ml) and dried under vacuum at 70 °C for 12 h to obtain intermediate 2.

[0046] S3: Under nitrogen protection, 750 ml of anhydrous tetrahydrofuran, 0.1 mol of intermediate 2, and 0.205 mol of 3-aminopropyltrimethoxysilane were stirred and mixed. 0.21 mol of triethylamine was added, and the mixture was heated to 60 °C and reacted for 6 h. After cooling to room temperature, the mixture was filtered. 800 ml of cold anhydrous n-hexane was added to the filtrate and stirred to precipitate the precipitate. The precipitate was filtered, and the filter cake was washed with cold anhydrous n-hexane (3 × 50 ml). The mixture was then dried under vacuum at 50 °C for 8 h to obtain intermediate 3.

[0047] S4: Under nitrogen protection, 900 ml of anhydrous DMF, 0.1 mol of intermediate 3, and 0.23 mol of 5-chloro-1,2,3-benzenetricarboxylic acid were stirred and mixed. 3 mmol of Pd(OAc)2, 3.2 mmol of RuPhos, and 0.2 mol of K3PO4 were added, and the mixture was heated to 120 °C and reacted for 12 h. After cooling to room temperature, 800 ml of anhydrous toluene was added to the reaction solution, and the mixture was stirred thoroughly. The solution was filtered, and the filtrate was concentrated under reduced pressure at 70 °C for 1 h to obtain a concentrated solution. 500 ml of anhydrous ethyl acetate and 30 g of anhydrous potassium carbonate were added to the concentrated solution, and the mixture was stirred for 1 h. The solution was filtered, dried over 40 g of anhydrous magnesium sulfate for 2 h, filtered again, and distilled under reduced pressure at 45 °C for 2 h to obtain the crude product. The crude product was purified by silica gel column chromatography (petroleum ether / ethyl acetate V / V = 1:4) and distilled under reduced pressure at 40 °C for 5 h to obtain the modifier.

[0048] Example 4: Preparation of high-strength environmentally friendly ceramics:

[0049] (1) Weigh the following by weight: 200g diatomaceous earth, 150g albite, 50g talc, 30g pore-forming agent (ammonium bicarbonate), and 10g modifier (prepared in Example 1);

[0050] (2) After mixing the above raw materials, put them into a planetary ball mill, add 50 ml of anhydrous ethanol, use grinding balls with a diameter of 5 mm and 3 mm, the weight ratio of 5 mm grinding balls to 3 mm grinding balls is 2:1, the ball-to-material ratio is 15:1, grind at 300 r / min for 15 min, stop for 15 min, grind at 300 r / min for another 15 min to obtain a slurry, put the slurry into a vacuum drying oven, dry at 80℃ for 12 h to obtain powder;

[0051] (3) Put the powder into a grinder and grind it at 1500 r / min for 30 min. Then put it into a mold and press it under 100 MPa pressure for 30 min to form a blank.

[0052] (4) The blank is placed in a vacuum hot press furnace, the furnace cavity is kept in a vacuum state, nitrogen is filled in as a protective atmosphere, the temperature is raised to 1100℃ at a rate of 5℃ / min, and sintered at 10MPa pressure for 3h and then naturally cooled to room temperature to obtain high-strength environmentally friendly ceramics.

[0053] Example 5: Preparation of high-strength environmentally friendly ceramics:

[0054] (1) Weigh the following by weight: 300g diatomaceous earth, 250g albite, 100g talc, 70g pore-forming agent (ammonium bicarbonate), and 30g modifier (prepared in Example 2);

[0055] (2) After mixing the above raw materials, put them into a planetary ball mill, add 80 ml of anhydrous ethanol, use grinding balls with a diameter of 5 mm and 3 mm, the weight ratio of 5 mm grinding balls to 3 mm grinding balls is 2:1, the ball-to-material ratio is 15:1, grind at 300 r / min for 15 min, stop for 15 min, grind at 300 r / min for another 15 min to obtain a slurry, put the slurry into a vacuum drying oven, dry at 80℃ for 12 h to obtain powder;

[0056] (3) Put the powder into a grinder and grind it at 1500 r / min for 30 min. Then put it into a mold and press it under 100 MPa pressure for 30 min to form a blank.

[0057] (4) The blank is placed in a vacuum hot press furnace, the furnace cavity is kept in a vacuum state, nitrogen is filled in as a protective atmosphere, the temperature is raised to 1200℃ at a rate of 5℃ / min, and sintered at 15MPa pressure for 2.5h before naturally cooling to room temperature to obtain high-strength environmentally friendly ceramics.

[0058] Example 6: Preparation of high-strength environmentally friendly ceramics:

[0059] (1) Weigh the following by weight: 400g diatomaceous earth, 300g albite, 150g talc, 100g pore-forming agent (ammonium bicarbonate), and 50g modifier (prepared in Example 3);

[0060] (2) After mixing the above raw materials, put them into a planetary ball mill, add 110 ml of anhydrous ethanol, use grinding balls with a diameter of 5 mm and 3 mm, the weight ratio of 5 mm grinding balls to 3 mm grinding balls is 2:1, the ball-to-material ratio is 15:1, grind at 300 r / min for 15 min, stop for 15 min, grind at 300 r / min for another 15 min to obtain a slurry, put the slurry into a vacuum drying oven, dry at 80℃ for 12 h to obtain powder;

[0061] (3) Put the powder into a grinder and grind it at 1500 r / min for 30 min. Then put it into a mold and press it under 100 MPa pressure for 30 min to form a blank.

[0062] (4) The blank is placed in a vacuum hot press furnace, the furnace cavity is kept in a vacuum state, nitrogen is filled in as a protective atmosphere, the temperature is raised to 1300℃ at a rate of 5℃ / min, and sintered at 20MPa pressure for 2 hours and then naturally cooled to room temperature to obtain high-strength environmentally friendly ceramics.

[0063] Comparative Example 1

[0064] The raw material composition and preparation method of the high-strength environmentally friendly ceramic are basically the same as those in Example 5, except that the modifier is replaced with an equal weight of a modifier prepared by the following method:

[0065] The preparation method of the modifier is basically the same as that in Example 2, except that 4,4'-dithiodibutyric acid in step S1 is replaced with an equimolar amount of sebacic acid.

[0066] Comparative Example 2

[0067] The raw material composition and preparation method of the high-strength environmentally friendly ceramic are basically the same as those in Example 5, except that the modifier is replaced with an equal weight of a modifier prepared by the following method:

[0068] The preparation method of the modifier is basically the same as that in Example 2, except that 4-(1,3-dioxo-1,3,3A,4,7,7A-hexahydro-2H-4,7-methoxyisoindole-2-yl)benzoic acid in step S2 is replaced with an equimolar amount of 4-maleimide benzoic acid.

[0069] Comparative Example 3

[0070] The raw material composition and preparation method of the high-strength environmentally friendly ceramic are basically the same as those in Example 5, except that the modifier is replaced with an equal weight of a modifier prepared by the following method:

[0071] The preparation method of the modifier is basically the same as that in Example 2, except that 4-(1,3-dioxo-1,3,3A,4,7,7A-hexahydro-2H-4,7-methoxyisoindole-2-yl)benzoic acid in step S2 is replaced with an equimolar amount of 1,3,3A,4,7,7A-hexahydro-1,3-dioxo-4,7-methanol-2H-isoindole-2-acetic acid (CAS No.: 26749-93-9).

[0072] Comparative Example 4

[0073] The raw material composition and preparation method of the high-strength environmentally friendly ceramic are basically the same as those in Example 5, except that the modifier is replaced with an equal weight of a modifier prepared by the following method:

[0074] The preparation method of the modifier is basically the same as that in Example 2, except that 3-aminopropyltrimethoxysilane in step S3 is replaced with an equimolar amount of 3-aminopropylmethyldimethoxysilane.

[0075] Comparative Example 5

[0076] The raw material composition and preparation method of the high-strength environmentally friendly ceramic are basically the same as those in Example 5, except that the modifier is replaced with an equal weight of a modifier prepared by the following method:

[0077] The preparation method of the modifier is basically the same as that in Example 2, except that 5-chloro-1,2,3-benzenetricarboxylic acid in step S4 is replaced with an equimolar amount of 4-chlorophthalic acid.

[0078] The diatomaceous earth used in the embodiments and comparative examples of this application is flux-calcined diatomaceous earth, model TS505, produced by Qingdao Shengtai Silicon Industry Co., Ltd.; the albite has a mesh size of 200 and is produced by Henan Ankai New Materials Co., Ltd.; the talc powder has a model of HY-TA04 and is produced by Guangdong Haike New Materials Technology Co., Ltd.; the CAS number of 4-(1,3-dioxo-1,3,3A,4,7,7A-hexahydro-2H-4,7-methoxyisoindole-2-yl)benzoic acid is 55099-10-0; and the CAS number of 5-chloro-1,2,3-benzenetricarboxylic acid is 29016-74-8.

[0079] The mechanical properties and thermal insulation properties of the high-strength environmentally friendly ceramics prepared in Examples 4-6 and Comparative Examples 1-5 were tested, and the test results are shown in Table 1.

[0080] Mechanical property testing: The high-strength environmentally friendly ceramics prepared in Examples 4-6 and Comparative Examples 1-5 were cut into specimens with dimensions of 10mm × 10mm × 10mm. The surface of the specimens was polished smooth, and the compressive strength was measured using a universal testing machine at a loading rate of 0.5mm / min, according to the formula... (S: compressive strength of the specimen, MPa; P: pressure at which the specimen just fails, N; A: average pressure area of ​​the specimen, mm) 2 A1: Area of ​​the upper surface of the sample, mm 2 A2: Lower surface area of ​​the sample, mm 2 Calculate the compressive strength, repeat three times and take the average value.

[0081] Thermal insulation performance test: The thermal conductivity and apparent porosity of the high-strength environmentally friendly ceramics prepared in the examples and comparative examples were tested as indicators to evaluate their thermal insulation performance. The higher the apparent porosity and the lower the thermal conductivity, the better the thermal insulation performance. The high-strength environmentally friendly ceramics prepared in Examples 4-6 and Comparative Examples 1-5 were cut into samples with dimensions of 50mm × 50mm × 5mm.

[0082] The thermal conductivity was tested using the following method: the sample surface was polished flat, and the thermal conductivity of the sample was tested using the Xiaxi Technology TC3100 thermal conductivity tester. The test temperature was set to 25℃. The same sample was tested three times and the average value was taken as its final thermal conductivity.

[0083] Apparent porosity was tested using the following method: The cleaned sample was placed in a drying oven and dried at 110℃ ± 5℃ to constant weight. It was then cooled to room temperature in a desiccator, and the dry weight (m1) of the sample was measured to an accuracy of 0.001 g. The dried sample was placed in a vacuum container, and the vacuum pump was started to ensure the residual pressure in the container was less than 2500 Pa. The sample was held at this vacuum level for 15 min. The stopcock between the vacuum container and the storage bottle was opened, and distilled water was injected, increasing the water level to 20 mm above the sample within 3 min. Vacuuming continued for 30 min, and the vacuum pump was turned off to allow the vacuum container to return to normal pressure. The sample was then immersed at normal pressure for 30 min. The immersed saturated sample was placed in a basket and suspended in a container filled with distilled water and equipped with an overflow pipe. The suspended mass (m2) of the saturated sample in the distilled water was measured to an accuracy of 0.001 g. Select pure cotton towels according to GB / T29862, cut them into squares with sides of 14cm, soak them in distilled water for 5 minutes, remove them and fold them into squares with sides of 7cm. Lay them flat under the press head and apply pressure. The press head should completely cover the towel. Hold the pressure at 3.3kN±0.2kN for 10 seconds. Wipe away any liquid drained around the press head with a clean cotton cloth, then remove the towel containing distilled water. Remove the sample from the distilled water, wipe away any liquid adhering to the sample surface with the towel soaked in distilled water, and weigh the saturated sample in air (m3) within 30 seconds, accurate to 0.001g. The basket is made of 0.2mm diameter metal wire and used to weigh the saturated distilled water sample. The suspension wire is a clean, inelastic 0.2mm diameter wire. Calculate the apparent porosity using the following formula: p= .

[0084] Table 1

[0085]

[0086] As shown in Table 1, the high-strength environmentally friendly ceramics prepared in Examples 4-6 of this application exhibit high compressive strength, high apparent porosity, and low thermal conductivity, demonstrating excellent mechanical properties and thermal insulation performance. This is due to the presence of disulfide bonds, benzene rings, siloxane structures, norbornene structures, and multiple carboxyl groups in the added modifiers. During the green body stage, the carboxyl groups can form coordination bonds with metal ions in the ceramic raw materials (diatomite, albite, talc) and hydrogen bonds with hydroxyl groups on the surface of diatomite. The combined effect of coordination bonds and hydrogen bonds constructs a green body reinforcement network. Simultaneously, the siloxane structure can form Si-O-Si covalent bonds with hydroxyl groups on the surface of diatomite, further enhancing the bonding strength of the green body. The rigid structures of the benzene rings and norbornene prevent excessive molecular chain entanglement, ensuring uniform distribution of coordination bonds and further forming a reinforcement network, collectively improving the mechanical properties of the ceramic. During the intermediate temperature stage, disulfide bonds break and absorb energy, relieving stress caused by powder accumulation. The organic structures such as norbornene and carboxyl groups gradually decompose, releasing small-molecule olefins and CO2 gases, generating numerous pores within the green body, significantly increasing apparent porosity, reducing the thermal conductivity of the ceramic, and thus improving its thermal insulation performance. During the high-temperature sintering stage, the silica generated from the decomposition of siloxane structures participates in the formation of the glass phase of the ceramic, thereby improving the material's density and mechanical strength. The modifier used in Comparative Example 2 lacks a norbornene structure, which weakens rigidity, leading to a decrease in the ceramic's mechanical properties. Furthermore, it reduces the gases generated during sintering, lowering apparent porosity, increasing thermal conductivity, and decreasing thermal insulation performance. The modifier used in Comparative Example 4 has a weakened ability to form Si-O-Si covalent bonds with the hydroxyl groups on the diatomaceous earth surface, resulting in a weakened green network strength and a decrease in the mechanical properties of the final ceramic material.

[0087] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. However, any modifications, alterations, and variations made by those skilled in the art without departing from the scope of the present invention based on the disclosed technical content are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, and variations made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the present invention.

Claims

1. A high-strength, environmentally friendly ceramic, characterized in that, The raw materials include the following weight parts: diatomite 20-40 parts, sodium feldspar 15-30 parts, talcum powder 5-15 parts, pore forming agent 3-10 parts, modifier 1-5 parts; The modifier is prepared by the following method: S1: under nitrogen protection, anhydrous toluene, 4,4'-dithiodibutyric acid are stirred and mixed uniformly, and epichlorohydrin is slowly added dropwise; after the dropwise addition is completed, tetraethylammonium bromide and K2CO3 are added, and the reaction is carried out by increasing the temperature; after cooling to room temperature, vacuum distillation is carried out, cold n-hexane is added for stirring to precipitate the sediment, filtration is carried out, the filter cake is washed with cold n-hexane, and vacuum drying is carried out to obtain intermediate 1; S2: under nitrogen protection, anhydrous DMF, 4-(1,3-dioxo-1,3,3A,4,7,7A-hexahydro-2H-4,7-methoxyisoindol-2-yl)benzoic acid, 1-ethyl-(3-dimethylaminopropyl)carbonyldiimidazole hydrochloride and N-hydroxysuccinimide are mixed uniformly in an ice bath, and stirring is carried out to obtain an activated DMF solution of 4-(1,3-dioxo-1,3,3A,4,7,7A-hexahydro-2H-4,7-methoxyisoindol-2-yl)benzoic acid; the activated DMF solution of 4-(1,3-dioxo-1,3,3A,4,7,7A-hexahydro-2H-4,7-methoxyisoindol-2-yl)benzoic acid is slowly added dropwise to the anhydrous DMF solution containing intermediate 1, and the reaction is carried out after the dropwise addition is completed; filtration is carried out, and the filtrate is slowly poured into cold n-hexane for stirring to precipitate the sediment; filtration is carried out, the filter cake is washed with cold n-hexane, and vacuum drying is carried out to obtain intermediate 2; S3: under nitrogen protection, anhydrous tetrahydrofuran, intermediate 2 and 3-aminopropyltrimethoxysilane are stirred and mixed uniformly, and triethylamine is added; the reaction is carried out by increasing the temperature, and then cooling to room temperature; filtration is carried out, and cold anhydrous n-hexane is added to the filtrate for stirring to precipitate the sediment; filtration is carried out, the filter cake is washed with cold anhydrous n-hexane, and vacuum drying is carried out to obtain intermediate 3; S4: under nitrogen protection, anhydrous DMF, intermediate 3 and 5-chloro-1,2,3-benzenetricarboxylic acid are stirred and mixed uniformly, and Pd(OAc)2, RuPhos and K3PO4 are added; the reaction is carried out by increasing the temperature, and then cooling to room temperature; anhydrous toluene is added to the reaction solution, and stirring is carried out; filtration is carried out, the filtrate is concentrated under reduced pressure to obtain a concentrated solution; anhydrous ethyl acetate and anhydrous potassium carbonate are added to the concentrated solution, and stirring is carried out; filtration is carried out, and the filtrate is dried with anhydrous magnesium sulfate; filtration is carried out, and the crude product is obtained by vacuum distillation; the crude product is purified by silica gel column chromatography, and vacuum distillation is carried out to obtain the modifier; In step S1, the molar ratio of 4,4'-dithiodibutyric acid to epichlorohydrin is 1:(2.01-2.05); In step S2, the molar ratio of intermediate 1 to 4-(1,3-dioxo-1,3,3A,4,7,7A-hexahydro-2H-4,7-methoxyisoindol-2-yl)benzoic acid is 1:(2.1-2.2); In step S3, the molar ratio of intermediate 2 to 3-aminopropyltrimethoxysilane is 1:(2.01-2.05); In step S4, the molar ratio of intermediate 3 to 5-chloro-1,2,3-benzenetricarboxylic acid is 1:(2.1-2.3).

2. The high strength, environmentally friendly ceramic of claim 1, wherein, The reaction temperature of step S1 is 80-90℃, and the reaction time is 1.5-2.5h; the reaction temperature of step S2 is 25-30℃, and the reaction time is 8-9h.

3. The high strength, environmentally friendly ceramic of claim 1, wherein, The reaction temperature of step S3 is 50-60℃, and the reaction time is 6-8h; the reaction temperature of step S4 is 110-120℃, and the reaction time is 12-14h.

4. The high strength, environmentally friendly ceramic of claim 1, wherein, The pore-forming agent is ammonium bicarbonate.

5. A method of producing the high-strength, environmentally friendly ceramic according to any one of claims 1 to 4, characterized by, Comprise the following steps: (1) weigh according to parts by weight: diatomite 20-40 parts, sodium feldspar 15-30 parts, talcum powder 5-15 parts, pore-forming agent 3-10 parts, modifier 1-5 parts; (2) put the above raw materials after mixing into the planetary ball mill, add anhydrous ethanol for ball milling, get slurry, dry to get powder; (3) grind the powder and put it into the mold, press and form to get the green body; (4) heat-press sinter the green body, cool to get high-strength environmental protection ceramic.

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