Pressure-resistant sound-absorbing synthetic material and method for producing same

Abstract

The present application belongs to the field of sound-absorbing materials, and particularly relates to a pressure-resistant sound-absorbing synthetic material and a preparation method thereof. The pressure-resistant sound-absorbing synthetic material provided by the present application comprises an epoxy resin matrix and light-weight pressure-resistant fillers distributed in the epoxy resin matrix; the components of the epoxy resin matrix comprise epoxy resin, diluent, curing agent and coupling agent; the light-weight pressure-resistant fillers comprise mesoporous silica microspheres, hollow glass microbeads, millimeter-level polymer hollow spheres and centimeter-level polymer hollow spheres; and the polymer matrix of the ball wall of the millimeter-level polymer hollow spheres and the centimeter-level polymer hollow spheres is polyurethane. The pressure-resistant sound-absorbing synthetic material provided by the present application has good pressure-resistant strength and sound-absorbing capacity.

Description

Technical Field

[0001] This invention belongs to the field of sound-absorbing materials, and particularly relates to a pressure-resistant sound-absorbing synthetic material and its preparation method. Background Technology

[0002] Underwater sound-absorbing materials refer to functional materials that can effectively absorb the energy of sound waves in water and reduce sound reflection. Their core function is to convert incident sound waves into heat energy or other forms of energy through the energy dissipation mechanism of the material's internal structure or components, thereby reducing the sound reflection cross section of the target object. These materials are widely used in the following fields: (1) Marine engineering: used for acoustic stealth design of underwater vehicles such as submarines and ships to reduce the probability of being detected by sonar; noise reduction treatment of underwater pipelines, marine platforms and other structures to reduce marine noise pollution; (2) Acoustic measurement: used as lining material for anechoic pools and anechoic chambers to provide a low-reflection acoustic environment for underwater acoustic equipment testing; (3) Civil field: underwater sound barriers, port noise prevention facilities, etc., used to control the impact of noise generated by underwater construction and ship navigation on marine life.

[0003] As a key material in marine engineering and acoustics, the development of underwater sound-absorbing materials directly impacts the stealth performance of underwater equipment, marine noise control levels, and the accuracy of acoustic measurements. Therefore, developing an underwater sound-absorbing material that combines good compressive strength with sound absorption capabilities is essential. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a pressure-resistant sound-absorbing synthetic material and its preparation method. The pressure-resistant sound-absorbing synthetic material provided by the present invention has both good pressure resistance and sound absorption capacity.

[0005] This invention provides a pressure-resistant sound-absorbing synthetic material, comprising an epoxy resin matrix and lightweight pressure-resistant fillers distributed within the epoxy resin matrix;

[0006] The epoxy resin matrix comprises epoxy resin, diluent, curing agent, and coupling agent;

[0007] The lightweight pressure-resistant filler includes mesoporous silica microspheres, hollow glass microspheres, millimeter-sized polymer hollow spheres, and centimeter-sized polymer hollow spheres;

[0008] The mesoporous silica microspheres have a particle size of 2~20μm and a pore size of 3~30nm;

[0009] The hollow glass microspheres have a particle size of 30~100μm and a wall thickness of 0.5~2μm;

[0010] The millimeter-sized polymer hollow spheres have a particle size of 2-10 mm and a wall thickness of 0.1-1 mm, and the polymer matrix of the sphere wall is polyurethane.

[0011] The centimeter-sized polymer hollow spheres have a particle size of 1-5 cm and a wall thickness of 0.5-6 mm, with the polymer matrix of the sphere wall being polyurethane.

[0012] Preferably, the hollow glass microspheres are made of soda lime borosilicate glass.

[0013] Preferably, the polymer matrix of the millimeter-sized and / or centimeter-sized hollow polymer spheres contains micron-sized hollow filler spheres distributed within it.

[0014] Preferably, the material of the micron-sized hollow filler spheres is sodium-calcium borosilicate glass.

[0015] Preferably, the epoxy resin is a bisphenol A type epoxy resin.

[0016] Preferably, the diluent is glycidyl ether; the curing agent is dodecenyl succinic anhydride; and the coupling agent is KH550 silane coupling agent.

[0017] Preferably, the mass ratio of the epoxy resin, diluent, curing agent and coupling agent is 100:(5~30):(100~120):(0.5~15).

[0018] Preferably, the mass ratio of the epoxy resin, mesoporous silica microspheres, hollow glass microspheres, millimeter-sized polymer hollow spheres, and centimeter-sized polymer hollow spheres is 100:(15~30):(30~120):(30~100):(100~240).

[0019] Preferably, the mesoporous silica microspheres, hollow glass microspheres, millimeter-sized hollow polymer spheres, and centimeter-sized hollow polymer spheres are uniformly distributed or distributed according to a particle size gradient within the epoxy resin matrix.

[0020] This invention provides a method for preparing the pressure-resistant sound-absorbing synthetic material described in the above technical solution, comprising the following steps:

[0021] An epoxy resin, diluent, curing agent, coupling agent, mesoporous silica microspheres, hollow glass microspheres, millimeter-sized polymer hollow spheres, and centimeter-sized polymer hollow spheres are filled into a mold and then heated to cure, resulting in a pressure-resistant and sound-absorbing synthetic material.

[0022] Compared with existing technologies, this invention provides a pressure-resistant sound-absorbing synthetic material and its preparation method. The pressure-resistant sound-absorbing synthetic material provided by this invention comprises an epoxy resin matrix and lightweight pressure-resistant fillers distributed within the epoxy resin matrix; the epoxy resin matrix comprises epoxy resin, diluent, curing agent, and coupling agent; the lightweight pressure-resistant fillers comprise mesoporous silica microspheres, hollow glass microspheres, millimeter-sized polymer hollow spheres, and centimeter-sized polymer hollow spheres; the mesoporous silica microspheres have a particle size of 2-20 μm and a pore size of 3-30 nm; the hollow glass microspheres have a particle size of 30-100 μm and a wall thickness of 1-2 μm; the millimeter-sized polymer hollow spheres have a particle size of 2-10 mm and a wall thickness of 0.1-1 mm, with the sphere wall polymer matrix being polyurethane; the centimeter-sized polymer hollow spheres have a particle size of 1-5 cm and a wall thickness of 0.8-6 mm, with the sphere wall polymer matrix being polyurethane. This invention broadens the sound absorption frequency range of a material by constructing nanoscale to centimeter-scale porous structures within the material system, introducing a cavity resonant sound absorption mechanism while simultaneously achieving viscoelastic sound absorption in polyurethane. By selecting a high-strength epoxy resin as the matrix and preferably reinforcing the polyurethane sound-absorbing material with micron-sized hollow filler spheres, the invention ensures that the material possesses both excellent hydrostatic pressure resistance and superior sound absorption performance. The pressure-resistant sound-absorbing composite material provided by this invention combines excellent pressure resistance and sound absorption capacity, and can be applied to working water depths ranging from hundreds to thousands of meters, meeting the underwater acoustic application requirements of specific deep-sea exploration, vehicles, and equipment. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0024] Figure 1 This is a schematic diagram illustrating the preparation of a pressure-resistant sound-absorbing synthetic material with uniformly distributed filler, as provided in an embodiment of the present invention.

[0025] Figure 2 This is a schematic diagram illustrating the preparation of a pressure-resistant sound-absorbing synthetic material with filler distributed according to a particle size gradient, as provided in an embodiment of the present invention.

[0026] Explanation of reference numerals in the attached figures: 1 is mesoporous silica microspheres, 2 is hollow glass microspheres, 3 is millimeter-sized polymer hollow spheres, 4 is centimeter-sized polymer hollow spheres, 5 is mold, 6 is release cloth, and 7 is flow guide net. Detailed Implementation

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below. 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 skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] The present invention provides a pressure-resistant sound-absorbing synthetic material, comprising an epoxy resin matrix and lightweight pressure-resistant fillers distributed within the epoxy resin matrix.

[0029] In the pressure-resistant sound-absorbing synthetic material provided by the present invention, the epoxy resin matrix comprises epoxy resin, diluent, curing agent, and coupling agent; wherein, the epoxy resin is preferably bisphenol A type epoxy resin; the epoxy equivalent of the bisphenol A type epoxy resin is preferably 150~200 g / eq, specifically 185.6 g / eq; the diluent is preferably glycidyl ether; the curing agent is preferably dodecenyl succinic anhydride; and the coupling agent is preferably KH550 silane coupling agent.

[0030] In the pressure-resistant sound-absorbing synthetic material provided by the present invention, the preferred mass ratio of epoxy resin, diluent, curing agent, and coupling agent in the epoxy resin matrix is ​​100:(5~30):(100~120):(0.5~15); wherein, the specific mass ratio of epoxy resin to diluent can be 100:5, 100:6, 100:7, 100:8, 100:9, 100:10, 100:11, 1... 00:12, 100:13, 100:14, 100:15, 100:16, 100:17, 100:18, 100:19, 100:20, 100:21, 100:22, 100:23, 100:24, 100:25, 100:26, 100:27, 100:28, 100:29 or 100:30; the mass ratio of the epoxy resin to the curing agent is... The ratios can be 100:100, 100:101, 100:102, 100:103, 100:104, 100:105, 100:106, 100:107, 100:108, 100:109, 100:110, 100:111, 100:112, 100:113, 100:114, 100:115, 100:116, 100:117. The specific mass ratio of epoxy resin to coupling agent can be 100:0.5, 100:1, 100:2, 100:3, 100:4, 100:5, 100:6, 100:7, 100:8, 100:9, 100:10, 100:11, 100:12, 100:13, 100:14, or 100:15.

[0031] In the pressure-resistant sound-absorbing synthetic material provided by the present invention, the lightweight pressure-resistant filler includes mesoporous silica microspheres, hollow glass microspheres, millimeter-sized polymer hollow spheres, and centimeter-sized polymer hollow spheres.

[0032] In the pressure-resistant sound-absorbing composite material provided by the present invention, the particle size of the mesoporous silica microspheres is 2~20μm, specifically 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, 19μm, or 20μm; the pore size of the mesoporous silica microspheres is 3~30nm, specifically 3nm, 4nm, 5nm, 6nm, 7nm, 8nm, 9nm, 10nm, or 11nm. The porosity of the mesoporous silica microspheres is preferably 40-80%, specifically 40%, 42%, 45%, 47%, 50%, 52%, 55%, 57%, 60%, 62%, 65%, 67%, 70%, 72%, 75%, 77%, or 80%.

[0033] In the pressure-resistant sound-absorbing synthetic material provided by the present invention, the preferred mass ratio of the mesoporous silica microspheres to the epoxy resin is (15~30):100, specifically 15:100, 16:100, 17:100, 18:100, 19:100, 20:100, 21:100, 22:100, 23:100, 24:100, 25:100, 26:100, 27:100, 28:100, 29:100 or 30:100.

[0034] In the pressure-resistant sound-absorbing composite material provided by the present invention, the particle size of the hollow glass microspheres is 30~100μm, specifically 30μm, 35μm, 40μm, 45μm, 50μm, 55μm, 60μm, 65μm, 70μm, 75μm, 80μm, 85μm, 90μm, 95μm or 100μm; the wall thickness of the hollow glass microspheres is 0.5~2μm, specifically 0.5μm, 0.6μm, 0.7μm, 0.8μm, 0.9μm, 1μm, 1.1μm, 1.2μm, 1.3μm, 1.4μm, 1.5μm, 1.6μm, 1.7μm, 1.8μm, 1.9μm or 2μm; the material of the hollow glass microspheres is preferably soda lime borosilicate glass.

[0035] In the pressure-resistant sound-absorbing synthetic material provided by the present invention, the preferred mass ratio of hollow glass microspheres to epoxy resin is (30~120):100, specifically 30:100, 31:100, 32:100, 33:100, 34:100, 35:100, 37:100, 40:100, 45:100, 50:100, 55:100, 60:100, 65:100, 70:100, 75:100, 80:100, 85:100, 90:100, 95:100, 100:100, 105:100, 110:100, 115:100 or 120:100.

[0036] In the pressure-resistant sound-absorbing synthetic material provided by the present invention, the particle size of the millimeter-sized polymer hollow spheres is 2~10mm, specifically 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm or 10mm; the wall thickness of the millimeter-sized polymer hollow spheres is 0.1~1mm, specifically 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm or 1mm; the polymer matrix of the sphere wall of the millimeter-sized polymer hollow spheres is polyurethane.

[0037] In the pressure-resistant sound-absorbing composite material provided by the present invention, micron-sized hollow filler spheres are preferably distributed within the polymer matrix of the millimeter-sized polymer hollow spheres; the material of the micron-sized hollow filler spheres is preferably sodium-calcium borosilicate glass; the particle size of the micron-sized hollow filler spheres is preferably 10~50μm, specifically 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm or 50μm; the content of the micron-sized hollow filler spheres in the millimeter-sized polymer hollow spheres is preferably 20~50wt%, specifically 20wt%, 23wt%, 25wt%, 27wt%, 30wt%, 32wt%, 35wt%, 37wt%, 40wt%, 42wt%, 45wt%, 47wt% or 50wt%.

[0038] In the pressure-resistant sound-absorbing composite material provided by the present invention, the matrix of the millimeter-sized polymer hollow sphere is composed of polyurethane with flexible chain segments, and preferably uses micron-sized hollow filler spheres to enhance mechanical properties and adjust density, ultimately forming a composite hollow sphere with millimeter-sized cavities inside and micron-sized cavities in the sphere wall. This polymer hollow sphere is a sound-absorbing filler with adjustable density and high water pressure resistance.

[0039] In the pressure-resistant sound-absorbing synthetic material provided by the present invention, the preferred mass ratio of the millimeter-sized polymer hollow spheres to epoxy resin is (30~100):100, specifically 30:100, 31:100, 32:100, 33:100, 34:100, 35:100, 37:100, 40:100, 45:100, 50:100, 55:100, 60:100, 65:100, 70:100, 75:100, 80:100, 85:100, 90:100, 95:100 or 100:100.

[0040] In the pressure-resistant sound-absorbing synthetic material provided by the present invention, the particle size of the centimeter-sized polymer hollow spheres is 1~5cm, specifically 1cm, 1.2cm, 1.5cm, 1.7cm, 2cm, 2.3cm, 2.5cm, 2.7cm, 3cm, 3.2cm, 3.5cm, 3.7cm, 4cm, 4.2cm, 4.5cm, 4.7cm or 5cm; the wall thickness of the centimeter-sized polymer hollow spheres is 0.5~6mm, specifically 0.5mm, 0.7mm, 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm or 6mm; the polymer matrix of the sphere wall of the centimeter-sized polymer hollow spheres is polyurethane.

[0041] In some embodiments provided by the present invention, the centimeter-sized polymer hollow spheres include polymer hollow spheres with a particle size of 3 cm and polymer hollow spheres with a particle size of 1.5 cm; the mass ratio of the polymer hollow spheres with a particle size of 3 cm to the polymer hollow spheres with a particle size of 1.5 cm is preferably 2:(1~2), specifically 2:1.5.

[0042] In the pressure-resistant sound-absorbing synthetic material provided by the present invention, micron-sized hollow filler spheres are preferably distributed within the polymer matrix of the centimeter-sized polymer hollow spheres; the material of the micron-sized hollow filler spheres is preferably sodium-calcium borosilicate glass; the particle size of the micron-sized hollow filler spheres is preferably 10~50μm, specifically 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm or 50μm; the content of the micron-sized hollow filler spheres in the centimeter-sized polymer hollow spheres is preferably 20~50wt%, specifically 20wt%, 23wt%, 25wt%, 27wt%, 30wt%, 32wt%, 35wt%, 37wt%, 40wt%, 42wt%, 45wt%, 47wt% or 50wt%.

[0043] In the pressure-resistant sound-absorbing composite material provided by the present invention, the matrix of the centimeter-sized polymer hollow sphere is composed of polyurethane with flexible chain segments, and preferably uses micron-sized hollow filler spheres to enhance mechanical properties and adjust density, ultimately forming a composite hollow sphere with centimeter-sized cavities inside and micron-sized cavities in the sphere wall. This polymer hollow sphere is a sound-absorbing filler with adjustable density and high water pressure resistance.

[0044] In the pressure-resistant sound-absorbing synthetic material provided by the present invention, the preferred mass ratio of the centimeter-sized polymer hollow spheres to epoxy resin is (100~240):100, specifically 100:100, 105:100, 110:100, 115:100, 116:100, 117:100, 120:100, 125:100, 130:100, 140:100, 150:100, 160:100, 170:100, 180:100, 190:100, 200:100, 210:100, 220:100, 230:100 or 240:100.

[0045] In the pressure-resistant sound-absorbing composite material provided by this invention, the mesoporous silica microspheres, hollow glass microspheres, millimeter-sized polymer hollow spheres, and centimeter-sized polymer hollow spheres are preferably uniformly distributed or distributed according to a particle size gradient within an epoxy resin matrix. For the uniformly distributed structure, the characteristic is that nanometer to centimeter-sized wide-pore fillers are uniformly composited within the material, ensuring that the material generates uniform and controllable elastic compression when subjected to uniform hydrostatic pressure, achieving stable and reliable broadband dissipation under deep-sea high pressure. For the gradient distributed structure, by arranging multi-level pores in order of increasing pore size, a transition layer with continuously varying acoustic impedance can be constructed from the sound wave incident surface to the backing direction, thereby achieving broadband matching and frequency-division dissipation of underwater acoustic waves.

[0046] The present invention also provides a method for preparing the pressure-resistant sound-absorbing synthetic material described in the above technical solution, comprising the following steps:

[0047] An epoxy resin, diluent, curing agent, coupling agent, mesoporous silica microspheres, hollow glass microspheres, millimeter-sized polymer hollow spheres, and centimeter-sized polymer hollow spheres are filled into a mold and then heated to cure, resulting in a pressure-resistant and sound-absorbing synthetic material.

[0048] In the preparation method provided by this invention, for a material with uniformly distributed lightweight pressure-resistant filler, the specific filling process preferably includes:

[0049] Millimeter-sized and centimeter-sized hollow polymer spheres are uniformly mixed and placed in a mold, then preheated at 50-60°C for 8-24 hours. Epoxy resin, diluent, coupling agent, and curing agent are added to a mixing tank and stirred at 30-50°C under vacuum for 10-20 minutes. Mesoporous silica microspheres and hollow glass microspheres are added to the mixing tank and stirred at 30-50°C under vacuum for 20-40 minutes to obtain a mixed slurry. The mixed slurry is then transferred into the preheated mold using vacuum-assisted casting technology. This completes the filling of all materials. Figure 1 As shown.

[0050] In the preparation method provided by this invention, for lightweight pressure-resistant fillers distributed according to a particle size gradient, the specific filling process preferably includes:

[0051] A release cloth and a flow guide net are laid inside the mold. Mesoporous silica microspheres, hollow glass microspheres, millimeter-sized hollow polymer spheres, and centimeter-sized hollow polymer spheres are placed inside the mold in descending order of particle size. The mold is then preheated at 50-60°C for 8-24 hours. Epoxy resin, diluent, coupling agent, and curing agent are added to a mixing tank and stirred for 10-20 minutes at 30-50°C under vacuum to obtain an epoxy resin slurry. The epoxy resin slurry is then injected into the preheated mold using vacuum-assisted casting molding technology. This completes the filling of all materials. Figure 2 As shown.

[0052] In the preparation method provided by the present invention, the heating and curing temperature is preferably 110~150℃, specifically 110℃, 115℃, 120℃, 125℃, 130℃, 135℃, 140℃, 145℃ or 150℃; the heating and curing time is preferably 4~12h, specifically 4h, 5h, 6h, 7h, 8h, 9h, 10h, 11h or 12h.

[0053] The technical solution provided by this invention can obtain a sound-absorbing composite material that possesses both good compressive strength and sound absorption capacity. More specifically, the technical solution of this invention has at least the following advantages:

[0054] (1) By selecting high-strength epoxy resin as the matrix and using micron-sized hollow filler balls to reinforce the polyurethane sound-absorbing material, the material is guaranteed to have both good hydrostatic pressure resistance and good sound absorption performance. The average sound absorption coefficient of the material under 6MPa hydrostatic pressure can reach more than 0.65.

[0055] (2) By constructing a uniformly distributed pore / gradient pore structure from nanopores to centimeter cavities in the material system, a cavity resonance sound absorption mechanism is introduced while polyurethane viscoelastic sound absorption is achieved, thus broadening the sound absorption frequency range of the material.

[0056] (3) By adjusting the filling ratio of lightweight pressure-resistant filler, the density of the sound-absorbing material provided by the present invention can be controlled, thereby obtaining a lighter sound-absorbing material.

[0057] For clarity, the following examples and comparative models will be used to provide a detailed description.

[0058] In the following embodiments of the present invention, the polyurethane hollow spheres with a particle size of 5 mm have a wall thickness of 0.2 mm, the polyurethane hollow spheres with a particle size of 1.5 cm have a wall thickness of 0.7 mm, and the polyurethane hollow spheres with a particle size of 3 cm have a wall thickness of 1.8 mm; the sphere walls of all three types of polyurethane hollow spheres are filled with sodium calcium borosilicate glass hollow filler spheres with a particle size of 30 μm, and the filling amount is 35 wt% of the mass of the polyurethane hollow spheres.

[0059] Example 1

[0060] 2 kg of polyurethane hollow spheres with a particle size of 3 cm, 1.5 kg of polyurethane hollow spheres with a particle size of 1.5 cm, and 1 kg of polyurethane hollow spheres with a particle size of 5 mm were mixed and added to a mold, and preheated at 60℃ for 18 hours; 3 kg of bisphenol A type epoxy resin (epoxy equivalent of 185.6 g / eq), 0.8 kg of glycidyl ether, and 0.3 kg of... KH550 silane coupling agent and 3 kg of dodecenyl succinic anhydride were added to a stirred tank and stirred at 50°C under vacuum for 20 min. 0.5 kg of mesoporous silica microspheres (5 μm particle size, 20 nm pore size, 60% porosity) and 1 kg of hollow glass microspheres (50 μm particle size, 0.9 μm wall thickness, made of soda lime borosilicate glass) were added to the stirred tank and stirred at 50°C under vacuum for 40 min. The preheated mold was evacuated to -0.08 MPa, and the mixed material was injected into the mold. Then, it was heated and cured at 130°C for 8 h. After the material was cured, it was cooled and removed to obtain a pressure-resistant and sound-absorbing composite material with uniformly distributed multi-level pores.

[0061] Example 2

[0062] A flow guide net and a release cloth were laid under the mold. 2 kg of 3 cm diameter polyurethane hollow spheres, 1.5 kg of 1.5 cm diameter polyurethane hollow spheres, and 1 kg of 5 mm diameter polyurethane hollow spheres were added sequentially into the mold. Then, 1 kg of hollow glass microspheres (50 μm diameter, 0.9 μm wall thickness, made of soda-lime borosilicate glass) and 0.5 kg of mesoporous silica microspheres (5 μm diameter, 20 nm pore size, 60% porosity) were added sequentially to the mold. The mixture was preheated at 60℃ for 18 hours. 3 kg of bisphenol A epoxy resin (epoxy equivalent 185.6 g / eq), 0.8 kg of glycidyl ether, and 0.3 kg of… KH550 silane coupling agent and 3 kg of dodecenyl succinic anhydride were added to a mixing tank and stirred for 20 min at 50 °C under vacuum. The preheated mold was evacuated to -0.09 MPa, and the mixed material was injected into the mold. Then, it was heated and cured at 130 °C for 8 h. After the material was cured, it was cooled and removed to obtain a pressure-resistant sound-absorbing synthetic material with gradient multi-level pores.

[0063] Comparative Example 1

[0064] 5.5 kg of butyl rubber was plasticized in an internal mixer at a temperature of 120°C for 15 minutes. After internal mixing, it was mixed in an open mixing mill. 0.1 kg of sulfur, 0.07 kg of accelerator DM, 0.1 kg of stearic acid and 0.3 kg of zinc oxide were added to the mixing mill and mixed evenly. Ten triangular bags were then formed in a thin pass. 1 kg of mica powder (average particle size 52 μm, aspect ratio 80) and 0.5 kg of hollow glass microspheres (particle size 30 μm, wall thickness 1.3 μm) were added and mixed evenly. The mixture was then filled into a cavity mold. After mold closing, it was vulcanized at 150°C and 15 MPa for 30 minutes to obtain rubber sound-absorbing tiles.

[0065] Comparative Example 2

[0066] 4 kg of bisphenol A type epoxy resin (epoxy equivalent of 185.6 g / eq), 0.8 kg of glycidyl ether, 0.3 kg of KH550 silane coupling agent, and 4 kg of dodecenyl succinic anhydride were added to a stirred tank and stirred at 50°C under vacuum for 20 minutes. 4 kg of hollow glass microspheres (particle size of 40 μm, wall thickness of 0.8 μm, made of soda lime borosilicate glass) were added to the stirred tank and stirred at 50°C under vacuum for 40 minutes. The mixed material was poured into a mold and heated to 130°C for 8 hours to cure. After the material was cured, it was cooled and removed to obtain the microsphere resin composite material.

[0067] Performance Evaluation

[0068] The products in the examples and comparative examples were tested for density, compressive strength, elastic modulus, sound absorption coefficient, and insertion loss (6 MPa), and the following results were obtained:

[0069]

[0070] The results in the table above show that: ① Compared with Comparative Example 1, Examples 1 and 2 have higher compressive strength and higher average sound absorption coefficient at a water pressure of 6 MPa while having a lower density; ② Compared with Comparative Example 2, Examples 1 and 2 have a lower compressive strength while having the same density, but the sound absorption and sound insulation performance of the materials are greatly improved; ③ Compared with Example 1, Example 2 has better average sound absorption coefficient and average insertion loss.

[0071] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A pressure-resistant sound-absorbing composite material, characterized in that, It includes an epoxy resin matrix and lightweight, pressure-resistant fillers distributed within the epoxy resin matrix; The epoxy resin matrix comprises epoxy resin, diluent, curing agent, and coupling agent; The lightweight pressure-resistant filler includes mesoporous silica microspheres, hollow glass microspheres, millimeter-sized polymer hollow spheres, and centimeter-sized polymer hollow spheres; The mesoporous silica microspheres have a particle size of 2~20μm and a pore size of 3~30nm; The hollow glass microspheres have a particle size of 30~100μm and a wall thickness of 0.5~2μm; The millimeter-sized polymer hollow spheres have a particle size of 2-10 mm and a wall thickness of 0.1-1 mm, and the polymer matrix of the sphere wall is polyurethane. The centimeter-sized polymer hollow spheres have a particle size of 1-5 cm and a wall thickness of 0.5-6 mm, with the polymer matrix of the sphere wall being polyurethane.

2. The pressure-resistant sound-absorbing composite material according to claim 1, characterized in that, The hollow glass microspheres are made of soda lime borosilicate glass.

3. The pressure-resistant sound-absorbing composite material according to claim 1, characterized in that, The millimeter-sized and / or centimeter-sized hollow polymer spheres have micron-sized hollow filler spheres distributed within the polymer matrix of their sphere walls.

4. The pressure-resistant sound-absorbing composite material according to claim 3, characterized in that, The micron-sized hollow filler spheres are made of sodium-calcium borosilicate glass.

5. The pressure-resistant sound-absorbing composite material according to claim 1, characterized in that, The epoxy resin is a bisphenol A type epoxy resin.

6. The pressure-resistant sound-absorbing composite material according to claim 1, characterized in that, The diluent is glycidyl ether; the curing agent is dodecenyl succinic anhydride; and the coupling agent is KH550 silane coupling agent.

7. The pressure-resistant sound-absorbing composite material according to claim 1, characterized in that, The mass ratio of the epoxy resin, diluent, curing agent and coupling agent is 100:(5~30):(100~120):(0.5~15).

8. The pressure-resistant sound-absorbing composite material according to claim 1, characterized in that, The mass ratio of the epoxy resin, mesoporous silica microspheres, hollow glass microspheres, millimeter-sized polymer hollow spheres, and centimeter-sized polymer hollow spheres is 100:(15~30):(30~120):(30~100):(100~240).

9. The pressure-resistant sound-absorbing composite material according to claim 1, characterized in that, The mesoporous silica microspheres, hollow glass microspheres, millimeter-sized hollow polymer spheres, and centimeter-sized hollow polymer spheres are uniformly distributed or distributed according to a particle size gradient within the epoxy resin matrix.

10. A method for preparing the pressure-resistant sound-absorbing synthetic material according to any one of claims 1 to 9, characterized in that, Includes the following steps: An epoxy resin, diluent, curing agent, coupling agent, mesoporous silica microspheres, hollow glass microspheres, millimeter-sized polymer hollow spheres, and centimeter-sized polymer hollow spheres are filled into a mold and then heated to cure, resulting in a pressure-resistant and sound-absorbing synthetic material.

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