High-strength low-heat-conductivity foam glass and preparation method thereof

Abstract

The invention relates to the technical field of preparation of foam glass, in particular to high-strength and low-heat-conductivity foam glass and a preparation method thereof. The problems that existing foam glass is low in strength and high in heat conductivity are solved. According to the foam glass, waste glass and glass fibers are used as raw materials, silicon carbide is used as a foaming agent, borax is used as a fluxing agent, trisodium phosphate dodecahydrate is used as a foam stabilizer, modified polyurethane and silicon dioxide aerogel are used for modifying the foam glass, the porous structure advantage of the aerogel enables heat to be transmitted along a slender framework of the aerogel, the heat transfer flux is low, and the foam glass has good heat transfer performance. The heat loss in the transmission path is large, and due to the existence of the aerogel particles, the solid-phase transmission path of heat in the foam glass is more complex, the CF3 group low surface energy reduces the heat convection path and inhibits the solid-phase heat conduction, so that the foam glass has a lower heat conductivity coefficient, and the mechanical strength of the material is improved. Therefore, the durability and thermal insulation performance of the foam glass are enhanced.

Description

Technical Field

[0001] This invention relates to the field of foam glass preparation technology, specifically to a high-strength, low-thermal-conductivity foam glass and its preparation method. Background Technology

[0002] Foamed glass is a porous material formed by introducing numerous closed air bubbles into a glass matrix through special processing. It combines the advantages of both glass and foam materials, exhibiting good dimensional stability, low water absorption, and excellent fire resistance. Despite its many superior properties, foamed glass still has some shortcomings in practical applications, such as high thermal conductivity and low mechanical strength, which limits its use in applications requiring reduced heat conduction and high strength. Therefore, this invention presents a high-strength, low-thermal-conductivity foamed glass and its preparation method, which not only improves the material's performance but also broadens its application range in the construction, electronics, and industrial fields. Summary of the Invention

[0003] In order to overcome the above-mentioned technical problems, the present invention aims to provide a high-strength, low-thermal-conductivity foam glass and its preparation method, thereby solving the problems of low strength and high thermal conductivity of existing foam glass.

[0004] The objective of this invention can be achieved through the following technical solutions:

[0005] In a first aspect, this application provides a method for preparing high-strength, low-thermal-conductivity foam glass, comprising the following steps: Step A1: Add waste glass to a ball mill jar with a ball-to-material mass ratio of 2:1, mill for 30 minutes, and then sieve through a 200-mesh sieve to obtain waste glass powder; Step A2: Add glass fiber to the ball mill jar with a ball-to-material mass ratio of 2:1, mill for 30 minutes, and sieve through a 200-mesh sieve to obtain glass fiber powder; Step A3: Add waste glass powder, glass fiber powder, silicon carbide, borax and trisodium phosphate dodecahydrate to a ball mill jar with a ball-to-material mass ratio of 2:1. Mix for 3 hours, sieve through a 200-mesh sieve, place in a drying oven and dry at 95°C for 24 hours. Add to a mold and press into shape. Place in a muffle furnace and preheat to 700°C at a heating rate of 5°C / min for 30 minutes. Then heat to 950°C for foaming and sintering for 40 minutes. Cool down to 600°C for annealing and cooling to obtain foam glass. Step A4: Ultrasonically clean the foam glass for 15 minutes, repeat twice, and dry it in a drying oven at 60°C for 6 hours to obtain pretreated foam glass; Step A5: Polybutane glycol, dicyclohexylmethane diisocyanate, and dibutyltin dilaurate were added to a three-necked flask equipped with a stirrer and a reflux condenser. The mixture was heated to 80°C and stirred for 1 hour. 2,2-Dimethylolpropionic acid and 1,6-hexanediol were dissolved in N,N-dimethylacetamide and added to the flask. The mixture was stirred at 80°C for 1.5 hours. S-naphthol was dissolved in tetrahydrofuran and added dropwise to the flask. The mixture was stirred at 80°C for 3 hours. The mixture was cooled to 50°C, and triethylamine was added and reacted for 30 minutes. Deionized water was added dropwise, and tetrahydrofuran was removed by vacuum distillation. The mixture was then added to a three-necked flask equipped with a thermometer and a stirrer with 3-aminopropyltrimethoxysilane. The mixture was reacted at 75°C for 2 hours. The solid content was adjusted to 10% to obtain a modified waterborne polyurethane emulsion. Step A6: Add the modified waterborne polyurethane emulsion, trifluoropropylmethylcyclotrisiloxane, deionized water, and ethanol to a beaker equipped with a thermometer and a stirrer. Stir at 300 rpm for 10 min, adjust the pH to 3-4 with hydrochloric acid, raise the temperature to 55℃, stir for 10 min, let stand for 6 h, adjust the pH to 8 with ammonia, stir for 5 min, add pretreated foam glass to completely impregnate, transfer to a water bath and react at 45℃ for 2-10 min, age for 6 h, add hexamethyldisilazane solution, water bath at 45-50℃ for 8 h, and dry at 50℃ for 24 h to obtain high-strength, low-thermal-conductivity foam glass.

[0006] As a further embodiment of the present invention: the composition of the waste glass in step A1 is: SiO2 71.25%, Na2O 13.77%, CaO 6.37%, MgO 3.98%, Al2O3 2.56%, Fe2O3 0.18%, K2O 1.10%, TiO2 0.057%, and others 0.733%.

[0007] As a further aspect of the present invention: in step A3, the ratio of waste glass powder, glass fiber powder, silicon carbide, borax and trisodium phosphate dodecahydrate is 40-80g: 60-120g: 2-4g: 10-20g: 3-6g.

[0008] As a further embodiment of the present invention: in step A5, the proportions of polybutanediol, dicyclohexylmethane diisocyanate, dibutyltin dilaurate, 2,2-dimethylolpropionic acid, 1,6-hexanediol, N,N-dimethylacetamide, S-naphthol, tetrahydrofuran, triethylamine, deionized water, and 3-aminopropyltrimethoxysilane are 18.75-37.5g: 5.02-10.04g: 0.04-0.08g: 1.01-2.02g: 0.73-1.46g: 10-20mL: 2.195-4.39g: 40-80mL: 1.14-2.28g: 40-80mL: 3-6g.

[0009] As a further aspect of the present invention: the polybutanediol in step A5 is of type PTMG2000.

[0010] As a further aspect of the present invention: in step A6, the ratio of the amount of modified waterborne polyurethane emulsion, trifluoropropylmethylcyclotrisiloxane, deionized water, ethanol, pretreated foam glass and hexamethyldisilazane solution is 1.1-2.2g: 1-2mol: 6-12mol: 1-2mol: 10-20g: 20-40mL.

[0011] As a further aspect of the present invention: the molar concentration of hydrochloric acid in step A6 is 0.5 mol / L.

[0012] As a further aspect of the present invention: the molar concentration of ammonia in step A6 is 0.5 mol / L.

[0013] As a further aspect of the present invention: the volume fraction of the hexamethyldisilazane solution in step A6 is 15%.

[0014] The beneficial effects of this invention are: This invention discloses a high-strength, low-thermal-conductivity foamed glass, which is prepared using waste glass and glass fiber as raw materials, silicon carbide as a foaming agent, borax as a flux, and trisodium dodecahydrate as a foam stabilizer. Modified polyurethane and silica aerogel are used to modify the foamed glass, thereby changing the heat transfer mode inside the foamed glass and reducing the overall thermal conductivity of the foamed glass. This improves the strength of the foamed glass while significantly reducing its thermal conductivity, thus achieving a high-strength, low-thermal-conductivity effect.

[0015] To prepare a high-strength, low-thermal-conductivity foamed glass, waste glass and glass fiber are used as raw materials, silicon carbide as a foaming agent, borax as a flux, and trisodium dodecahydrate as a foam stabilizer. The high modulus of glass fiber effectively inhibits the propagation of matrix cracks. The increased surface roughness of the fiber after ball milling pretreatment enhances the mechanical bonding force with waste glass powder and improves compressive strength. Silicon carbide decomposes at high temperature to produce SiO gas, which reacts with the Na2O-CaO-SiO2 glass network to generate CO2 bubbles. Combined with the fluxing effect of borax, this forms pores. The uniform pore structure with narrow distribution and high closed-pore ratio increases the tortuosity of the heat conduction path and reduces the thermal conductivity. The hydroxyl groups in polybutane glycol and 2,2-dimethylolpropionic acid react with the isocyanate groups in dicyclohexylmethane diisocyanate under the catalysis of dibutyltin dilaurate to form urethane bonds. 1,6-hexanediol acts as a chain extender and reacts with the isocyanate groups. The hydroxyl groups in S-naphthol react with the isocyanate groups, and the amino groups in 3-aminopropyltrimethoxysilane react with the remaining isocyanate groups to obtain a siloxane-terminated polyurethane. The trimethoxysilane in siloxane-terminated polyurethane undergoes hydrolysis with the siloxane ring in trifluoropropylmethylcyclotrisiloxane to form a Si-O-Si three-dimensional network structure, yielding a modified polyurethane-silica aerogel. This aerogel exhibits a stable structure with mesoporous pores, allowing for better thermal insulation. Simultaneously, the binaphthyl group provides excellent thermal insulation; after sufficient reaction, the binaphthyl group is uniformly distributed throughout the aerogel structure, further enhancing its thermal insulation performance. A hydrophobic layer rich in CF3 groups is formed on the surface of the foam glass, reducing heat convection paths due to its low surface energy. Furthermore, the high electronegativity of fluorine atoms lowers the mean free path of phonons, inhibiting solid-phase heat conduction. The aerogel's loading reduces the internal porosity of the foam glass, increasing its density and improving its thermal insulation performance. Simultaneously, the presence of aerogel particles complicates the solid-phase heat transfer path within the foam glass, resulting in a lower thermal conductivity. This combination of enhanced overall material strength and reduced thermal conductivity addresses the need for building materials to possess both high strength and low thermal conductivity. Detailed Implementation

[0016] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0017] Example 1: This embodiment describes a method for preparing high-strength, low-thermal-conductivity foam glass, comprising the following steps: Step A1: Add waste glass to a ball mill jar with a ball-to-material mass ratio of 2:1, mill for 30 minutes, and then sieve through a 200-mesh sieve to obtain waste glass powder; Step A2: Add glass fiber to the ball mill jar with a ball-to-material mass ratio of 2:1, mill for 30 minutes, and sieve through a 200-mesh sieve to obtain glass fiber powder; Step A3: Add 40g of waste glass powder, 60g of glass fiber powder, 2g of silicon carbide, 10g of borax and 3g of trisodium phosphate dodecahydrate to a ball mill jar. The ball-to-material mass ratio is 2:1. Mix for 3 hours, sieve through a 200-mesh sieve, place in a drying oven and dry at 95℃ for 24 hours. Add to a mold and press into shape. Place in a muffle furnace and preheat to 700℃ at a heating rate of 5℃ / min for 30 minutes. Then heat to 950℃ for foaming and sintering for 40 minutes. Cool down to 600℃ for annealing and cooling to obtain foam glass. Step A4: Ultrasonically clean the foam glass for 15 minutes, repeat twice, and dry it in a drying oven at 60°C for 6 hours to obtain pretreated foam glass; Step A5: Add 18.75g of polybutane glycol, 5.02g of dicyclohexylmethane diisocyanate, and 0.04g of dibutyltin dilaurate to a three-necked flask equipped with a stirrer and a reflux condenser. Heat to 80℃ and stir for 1 hour. Dissolve 1.01g of 2,2-dimethylolpropionic acid and 0.73g of 1,6-hexanediol in 10mL of N,N-dimethylacetamide and add to the flask. Stir at 80℃ for 1.5 hours. 195g of S-binaphthol was dissolved in 40mL of tetrahydrofuran and added dropwise to a flask. The mixture was stirred at 80℃ for 3h, cooled to 50℃, and 1.14g of triethylamine was added and reacted for 30min. 40mL of deionized water was added dropwise, and tetrahydrofuran was removed by vacuum distillation. The mixture was then added to a three-necked flask equipped with a thermometer and a stirrer with 3g of 3-aminopropyltrimethoxysilane and reacted at 75℃ for 2h. The solid content was adjusted to 10% to obtain a modified waterborne polyurethane emulsion. Step A6: Add 1.1g of modified waterborne polyurethane emulsion, 1mol of trifluoropropylmethylcyclotrisiloxane, 6mol of deionized water, and 1mol of ethanol to a beaker equipped with a thermometer and a stirrer. Stir at 300r / min for 10min, adjust the pH to 3 with hydrochloric acid, raise the temperature to 55℃, stir for 10min, let stand for 6h, adjust the pH to 8 with ammonia, stir for 5min, add 10g of pretreated foam glass to completely impregnate, transfer to a water bath and react at 45℃ for 2min, age for 6h, add 20mL of hexamethyldisilazane solution, water bath at 45℃ for 8h, and dry at 50℃ for 24h to obtain high-strength, low-thermal-conductivity foam glass.

[0018] Example 2: This embodiment describes a method for preparing high-strength, low-thermal-conductivity foam glass, comprising the following steps: Step A1: Add waste glass to a ball mill jar with a ball-to-material mass ratio of 2:1, mill for 30 minutes, and then sieve through a 200-mesh sieve to obtain waste glass powder; Step A2: Add glass fiber to the ball mill jar with a ball-to-material mass ratio of 2:1, mill for 30 minutes, and sieve through a 200-mesh sieve to obtain glass fiber powder; Step A3: Add 60g of waste glass powder, 90g of glass fiber powder, 3g of silicon carbide, 15g of borax, and 4.5g of trisodium phosphate dodecahydrate to a ball mill jar. The ball-to-material mass ratio is 2:1. Mix for 3 hours, sieve through a 200-mesh sieve, place in a drying oven and dry at 95℃ for 24 hours. Add to a mold and press into shape. Place in a muffle furnace and preheat to 700℃ at a heating rate of 5℃ / min for 30 minutes. Then heat to 950℃ for foaming and sintering for 40 minutes. Cool down to 600℃ for annealing and cooling to obtain foam glass. Step A4: Ultrasonically clean the foam glass for 15 minutes, repeat twice, and dry it in a drying oven at 60°C for 6 hours to obtain pretreated foam glass; Step A5: Add 28.125g of polybutane glycol, 7.53g of dicyclohexylmethane diisocyanate, and 0.06g of dibutyltin dilaurate to a three-necked flask equipped with a stirrer and a reflux condenser. Heat to 80℃ and stir for 1 hour. Dissolve 1.515g of 2,2-dimethylolpropionic acid and 1.095g of 1,6-hexanediol in 15mL of N,N-dimethylacetamide and add to the flask. Stir at 80℃ for 1.5 hours. 2925g of S-binaphthol was dissolved in 60mL of tetrahydrofuran and added dropwise to a flask. The mixture was stirred at 80℃ for 3h, cooled to 50℃, and 1.71g of triethylamine was added and reacted for 30min. 60mL of deionized water was added dropwise, and tetrahydrofuran was removed by vacuum distillation. The mixture was then added to a three-necked flask equipped with a thermometer and a stirrer with 4.5g of 3-aminopropyltrimethoxysilane and reacted at 75℃ for 2h. The solid content was adjusted to 10% to obtain a modified waterborne polyurethane emulsion. Step A6: Add 1.65g of modified waterborne polyurethane emulsion, 1.5mol of trifluoropropylmethylcyclotrisiloxane, 9mol of deionized water, and 1.5mol of ethanol to a beaker equipped with a thermometer and a stirrer. Stir at 300r / min for 10min, adjust the pH to 3 with hydrochloric acid, raise the temperature to 55℃, stir for 10min, let stand for 6h, adjust the pH to 8 with ammonia, stir for 5min, add 15g of pretreated foam glass to completely impregnate, transfer to a water bath and react at 45℃ for 6min, age for 6h, add 30mL of hexamethyldisilazane solution, water bath at 47℃ for 8h, and dry at 50℃ for 24h to obtain high-strength, low-thermal-conductivity foam glass.

[0019] Example 3: This embodiment describes a method for preparing high-strength, low-thermal-conductivity foam glass, comprising the following steps: Step A1: Add waste glass to a ball mill jar with a ball-to-material mass ratio of 2:1, mill for 30 minutes, and then sieve through a 200-mesh sieve to obtain waste glass powder; Step A2: Add glass fiber to the ball mill jar with a ball-to-material mass ratio of 2:1, mill for 30 minutes, and sieve through a 200-mesh sieve to obtain glass fiber powder; Step A3: Add 80g of waste glass powder, 120g of glass fiber powder, 4g of silicon carbide, 20g of borax and 6g of trisodium phosphate dodecahydrate to a ball mill jar. The ball-to-material mass ratio is 2:1. Mix for 3 hours, sieve through a 200-mesh sieve, place in a drying oven and dry at 95℃ for 24 hours. Add to a mold and press into shape. Place in a muffle furnace and preheat to 700℃ at a heating rate of 5℃ / min for 30 minutes. Then heat to 950℃ for foaming and sintering for 40 minutes. Cool down to 600℃ for annealing and cooling to obtain foam glass. Step A4: Ultrasonically clean the foam glass for 15 minutes, repeat twice, and dry it in a drying oven at 60°C for 6 hours to obtain pretreated foam glass; Step A5: Add 37.5g of polybutane glycol, 10.04g of dicyclohexylmethane diisocyanate, and 0.08g of dibutyltin dilaurate to a three-necked flask equipped with a stirrer and reflux condenser. Heat to 80℃ and stir for 1 hour. Dissolve 2.02g of 2,2-dimethylolpropionic acid and 1.46g of 1,6-hexanediol in 20mL of N,N-dimethylacetamide and add to the flask. Stir at 80℃ for 1.5 hours. 0.39 g of S-binaphthol was dissolved in 80 mL of tetrahydrofuran and added dropwise to a flask. The mixture was stirred at 80 °C for 3 h, cooled to 50 °C, and 2.28 g of triethylamine was added and reacted for 30 min. 80 mL of deionized water was added dropwise, and tetrahydrofuran was removed by vacuum distillation. The mixture was then added to a three-necked flask equipped with a thermometer and a stirrer with 6 g of 3-aminopropyltrimethoxysilane and reacted at 75 °C for 2 h. The solid content was adjusted to 10% to obtain a modified waterborne polyurethane emulsion. Step A6: Add 2.2g of modified waterborne polyurethane emulsion, 2mol of trifluoropropylmethylcyclotrisiloxane, 12mol of deionized water, and 2mol of ethanol to a beaker equipped with a thermometer and a stirrer. Stir at 300r / min for 10min, adjust the pH to 4 with hydrochloric acid, raise the temperature to 55℃, stir for 10min, let stand for 6h, adjust the pH to 8 with ammonia, stir for 5min, add 20g of pretreated foam glass to completely impregnate, transfer to a water bath and react at 45℃ for 10min, age for 6h, add 40mL of hexamethyldisilazane solution, water bath at 50℃ for 8h, and dry at 50℃ for 24h to obtain high-strength, low-thermal-conductivity foam glass.

[0020] Comparative Example 1: This comparative example illustrates a method for preparing high-strength, low-thermal-conductivity foam glass, comprising the following steps: Step A1: Add waste glass to a ball mill jar with a ball-to-material mass ratio of 2:1, mill for 30 minutes, and then sieve through a 200-mesh sieve to obtain waste glass powder; Step A2: Add glass fiber to the ball mill jar with a ball-to-material mass ratio of 2:1, mill for 30 minutes, and sieve through a 200-mesh sieve to obtain glass fiber powder; Step A3: Add 80g of waste glass powder, 120g of glass fiber powder, 4g of silicon carbide, 20g of borax, and 6g of trisodium phosphate dodecahydrate to a ball mill jar. The ball-to-material mass ratio is 2:1. Mix for 3 hours, sieve through a 200-mesh sieve, and dry in a drying oven at 95℃ for 24 hours. Add the mixture to a mold and press it into shape. Place it in a muffle furnace and heat it to 700℃ at a heating rate of 5℃ / min for 30 minutes. Then heat it to 950℃ for foaming and sintering for 40 minutes. Cool it down to 600℃ for annealing and obtain foamed glass.

[0021] Comparative Example 2: This comparative example illustrates a method for preparing high-strength, low-thermal-conductivity foam glass, comprising the following steps: Step A1: Add waste glass to a ball mill jar with a ball-to-material mass ratio of 2:1, mill for 30 minutes, and then sieve through a 200-mesh sieve to obtain waste glass powder; Step A2: Add 80g of waste glass powder, 2g of silicon carbide, 10g of borax and 3g of trisodium phosphate dodecahydrate to a ball mill jar. The ball-to-material mass ratio is 2:1. Mix for 3 hours, sieve through a 200-mesh sieve, place in a drying oven and dry at 95℃ for 24 hours. Add to a mold and press into shape. Place in a muffle furnace and heat to 700℃ at a heating rate of 5℃ / min for 30 minutes. Then heat to 950℃ for foaming and sintering for 40 minutes. Cool down to 600℃ for annealing and cooling to obtain foam glass. Step A3: Ultrasonically clean the foam glass for 15 minutes, repeat twice, and dry it in a drying oven at 60°C for 6 hours to obtain pretreated foam glass; Step A4: Add 0.2 mol tetraethoxysilane, 0.6 mol deionized water, and 2 mol anhydrous ethanol to a beaker equipped with a thermometer and a stirrer. Stir at 300 r / min for 10 min, adjust the pH to 4 with concentrated nitric acid, raise the temperature to 55℃, stir for 10 min, let stand for 6 h, adjust the pH to 8 with ammonia, stir for 5 min, add 10 g of pretreated foam glass until submerged, transfer to a water bath and react at 45℃ for 10 min, age for 6 h, add 40 mL hexamethyldisilazane solution, water bath at 50℃ for 8 h, and dry at 10 MPa and 50℃ for 90 min to obtain high-strength, low-thermal-conductivity foam glass.

[0022] Comparative Example 3: This comparative example illustrates a method for preparing high-strength, low-thermal-conductivity foam glass, comprising the following steps: Step A1: Add waste glass to a ball mill jar with a ball-to-material mass ratio of 2:1, mill for 30 minutes, and then sieve through a 200-mesh sieve to obtain waste glass powder; Step A2: Add glass fiber to the ball mill jar with a ball-to-material mass ratio of 2:1, mill for 30 minutes, and sieve through a 200-mesh sieve to obtain glass fiber powder; Step A3: Add 80g of waste glass powder, 120g of glass fiber powder, 4g of silicon carbide, 20g of borax and 6g of trisodium phosphate dodecahydrate to a ball mill jar. The ball-to-material mass ratio is 2:1. Mix for 3 hours, sieve through a 200-mesh sieve, place in a drying oven and dry at 95℃ for 24 hours. Add to a mold and press into shape. Place in a muffle furnace and preheat to 700℃ at a heating rate of 5℃ / min for 30 minutes. Then heat to 950℃ for foaming and sintering for 40 minutes. Cool down to 600℃ for annealing and cooling to obtain foam glass. Step A4: Ultrasonically clean the foam glass for 15 minutes, repeat twice, and dry it in a drying oven at 60°C for 6 hours to obtain pretreated foam glass; Step A5: Add 37.5g of polybutane glycol, 10.04g of dicyclohexylmethane diisocyanate and 0.08g of dibutyltin dilaurate to a three-necked flask equipped with a stirrer and a reflux condenser. Heat to 80℃ and stir for 1h. Dissolve 2.02g of 2,2-dimethylolpropionic acid and 1.46g of 1,6-hexanediol in 20mL of N,N-dimethylacetamide and add to the flask. Stir at 80℃ for 1.5h. Add 80mL of deionized water dropwise and remove tetrahydrofuran by vacuum distillation to obtain the modified waterborne polyurethane emulsion. Step A6: Add 20g of modified waterborne polyurethane emulsion to a beaker, add 10g of pretreated foam glass and completely immerse for 30min, evaporate for 24h, and dry at 50℃ for 24h to obtain high-strength, low-thermal-conductivity foam glass.

[0023] Performance testing: The foam glass from Examples 1-3 and Comparative Examples 1-3 was processed into cuboids with a length of 40 mm, a width of 40 mm, and a height of 30 mm. The thermal conductivity was tested using a DR-S type transient planar heat source thermal conductivity meter at an ambient temperature of 25°C. The foam glass from Examples 1-3 and Comparative Examples 1-3 was processed into cubes with a side length of 20 mm, and compressive strength tests were conducted using a CMT6104 microcomputer-controlled electronic universal testing machine.

[0024] ; Referring to the table above, based on the comparison between Examples 1-3 and Comparative Examples 1-3, it can be seen that the foam glass obtained by using waste glass and glass fiber as raw materials and modifying them with modified polyurethane and silica aerogel has high strength and low thermal conductivity. Based on the comparison between Example 3 and Comparative Example 1, it can be seen that the compressive strength of the foam glass obtained by using waste glass and glass fiber as raw materials and modifying it with modified polyurethane and silica aerogel is higher than that of the foam glass prepared by using waste glass and glass fiber as raw materials. This indicates that the foam glass obtained by using waste glass and glass fiber as raw materials and modifying it with modified polyurethane and silica aerogel has excellent mechanical strength. Based on the comparison between Example 3 and Comparative Example 2, it can be seen that the compressive strength of the foam glass obtained by using waste glass and glass fiber as raw materials and modifying it with modified polyurethane and silica aerogel is higher than that of the foam glass obtained by using waste glass as raw materials and modifying it with silica aerogel. This indicates that the foam glass obtained by using waste glass and glass fiber as raw materials and modifying it with modified polyurethane and silica aerogel has excellent mechanical strength. Based on the comparison between Example 3 and Comparative Example 3, it can be seen that the compressive strength of the foam glass obtained by using waste glass and glass fiber as raw materials and modifying it with modified polyurethane and silica aerogel is higher than that of the foam glass obtained by using waste glass and glass fiber as raw materials and modifying it with water-based polyurethane. This indicates that the foam glass obtained by using waste glass and glass fiber as raw materials and modifying it with modified polyurethane and silica aerogel has excellent mechanical strength.

[0025] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0026] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in this application, they should all fall within the protection scope of the present invention.

Claims

1. A method for preparing high-strength, low-thermal-conductivity foam glass, characterized in that, Includes the following steps: Step A1: Grind the waste glass balls and sieve them to obtain waste glass powder; Step A2: Grind the glass fiber into powder and sieve it to obtain glass fiber powder; Step A3: Mix waste glass powder, glass fiber powder, silicon carbide, borax and trisodium phosphate dodecahydrate, sieve, dry, add into a mold and press into shape, heat up to preheat, heat up again to foam and sinter, cool down to anneal, and cool to obtain foam glass; Step A4: Ultrasonically clean the foam glass twice, then dry it to obtain pretreated foam glass; Step A5: Polybutane glycol, dicyclohexylmethane diisocyanate, and dibutyltin dilaurate are added to a flask and heated and stirred to react. 2,2-dimethylolpropionic acid and 1,6-hexanediol are dissolved in N,N-dimethylacetamide and added to the flask and stirred to react. S-naphthol is dissolved in tetrahydrofuran and added to the flask and stirred to react. After cooling, triethylamine is added and reacted. Deionized water is added and the mixture is distilled under reduced pressure. 3-aminopropyltrimethoxysilane is added to the flask and reacted. The solid content is adjusted to obtain a modified waterborne polyurethane emulsion. Step A6: Stir the modified waterborne polyurethane emulsion, trifluoropropylmethylcyclotrisiloxane, deionized water and ethanol, adjust the pH, raise the temperature, stir, let stand, adjust the pH, stir, add pretreated foam glass to completely impregnate, react in a water bath, age, add hexamethyldisilazane solution, water bath, dry, to obtain high-strength low thermal conductivity foam glass.

2. The method for preparing high-strength, low-thermal-conductivity foam glass according to claim 1, characterized in that, The composition of the waste glass mentioned in step A1 is: SiO2 71.25%, Na2O 13.77%, CaO 6.37%, MgO 3.98%, Al2O3 2.56%, Fe2O3 0.18%, K2O 1.10%, TiO2 0.057%, and others 0.733%.

3. The method for preparing high-strength, low-thermal-conductivity foam glass according to claim 1, characterized in that, The ratio of waste glass powder, glass fiber powder, silicon carbide, borax and trisodium phosphate dodecahydrate used in step A3 is 40-80g: 60-120g: 2-4g: 10-20g: 3-6g.

4. The method for preparing high-strength, low-thermal-conductivity foam glass according to claim 1, characterized in that, The ratio of polybutanediol, dicyclohexylmethane diisocyanate, dibutyltin dilaurate, 2,2-dimethylolpropionic acid, 1,6-hexanediol, N,N-dimethylacetamide, S-naphthol, tetrahydrofuran, triethylamine, deionized water, and 3-aminopropyltrimethoxysilane in step A5 is 18.75-37.5g: 5.02-10.04g: 0.04-0.08g: 1.01-2.02g: 0.73-1.46g: 10-20mL: 2.195-4.39g: 40-80mL: 1.14-2.28g: 40-80mL: 3-6g.

5. The method for preparing high-strength, low-thermal-conductivity foam glass according to claim 1, characterized in that, The polybutanediol mentioned in step A5 is of type PTMG2000.

6. The method for preparing high-strength, low-thermal-conductivity foam glass according to claim 1, characterized in that, The ratio of the modified waterborne polyurethane emulsion, trifluoropropylmethylcyclotrisiloxane, deionized water, ethanol, pretreated foam glass, and hexamethyldisilazane solution in step A6 is 1.1-2.2g: 1-2mol: 6-12mol: 1-2mol: 10-20g: 20-40mL.

7. The method for preparing high-strength, low-thermal-conductivity foam glass according to claim 1, characterized in that, The volume fraction of the hexamethyldisilazane solution in step A6 is 15%.

8. A high-strength, low-thermal-conductivity foam glass, characterized in that, It is prepared by the method for preparing high-strength, low-thermal-conductivity foam glass according to any one of claims 1-7.