Porous ceramic-polymer composite material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of sound absorption materials, and particularly relates to a porous ceramic-polymer composite material and a preparation method and application thereof. The porous ceramic-polymer composite material provided by the invention comprises a polymer matrix and porous ceramic particles dispersed in the polymer matrix, the polymer matrix comprises rubber or polyvinyl chloride, the mass of the porous ceramic particles accounts for 10-50% of the mass of the polymer matrix, the porosity of the porous ceramic particles is greater than or equal to 33%, the particle size is 0.06-0.5 mm, and the porosity of the porous ceramic particles is greater than or equal to 30%. The pore size distribution is greater than or equal to 227 nm. The porous ceramic particles are introduced into the polymer matrix, so that the sound absorption performance of the polymer matrix can be remarkably improved, and noise pollution can be effectively reduced.

Description

Technical Field

[0001] This invention belongs to the field of sound-absorbing materials technology, specifically relating to a porous ceramic-polymer composite material, its preparation method, and its application. Background Technology

[0002] Noise pollution is one of the four major environmental hazards in today's society. Noise slowly harms people's health, causing emotional distress and disrupting normal cognitive functions in daily life and work. Noise also affects sleep and rest. Long-term exposure to noisy environments can lead to various noise-related illnesses. Due to damage to the nervous system, symptoms generally include dizziness, headaches, insomnia, fatigue, irritability, memory loss, poor concentration, tinnitus, and hearing loss. In more severe cases, it can even cause heart disease and high blood pressure.

[0003] In reality, sound-absorbing materials such as polymer materials like rubber have a narrow absorption frequency band and poor sound absorption performance. Summary of the Invention

[0004] The purpose of this invention is to provide a porous ceramic-polymer composite material, its preparation method, and its application. The porous ceramic-polymer composite material provided by this invention has a wider absorption frequency band and, compared with blank polymer materials (rubber or polyvinyl chloride), has superior sound absorption performance, thereby effectively reducing noise pollution.

[0005] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a porous ceramic-polymer composite material, comprising a polymer matrix and porous ceramic particles dispersed in the polymer matrix. The polymer matrix comprises rubber or polyvinyl chloride. The mass percentage of the porous ceramic particles in the polymer matrix is ​​10-50%. The porosity of the porous ceramic particles is ≥33%. The particle size of the porous ceramic particles is 0.06-0.5 mm. The pore size distribution of the porous ceramic particles is ≥227 nm.

[0006] Preferably, when the polymer matrix is ​​rubber, the porous ceramic particles are modified porous ceramic particles, and the modified porous ceramic particles are porous ceramic particles modified with nitrile rubber surface.

[0007] Preferably, the porosity of the porous ceramic particles is 33-63%.

[0008] Preferably, the porous ceramic particles have a particle size of 0.06~0.3mm.

[0009] Preferably, the pore size distribution of the porous ceramic particles is 220~6050nm.

[0010] Preferably, the method for preparing the porous ceramic particles includes the following steps: Ceramic aggregate, pore-forming agent, and binder are wet-mixed to obtain a mixture. The ceramic aggregate includes kaolin, feldspar, and quartz, with the mass ratio of kaolin to feldspar being 4:(3~9) and the mass ratio of kaolin to quartz being 4:(1~3). The pore-forming agent includes one or more of polyvinyl alcohol, polymethyl methacrylate, acrylate copolymers, and polystyrene, and the mass percentage of the pore-forming agent in the ceramic aggregate is 10~35%. The mixture is pressed into a molded shape to obtain a molded body; The molded body is dried, crushed, and sieved in sequence to obtain ceramic particles; The ceramic particles are sintered to obtain the porous ceramic material. The sintering includes the following steps: heating to a first temperature at a first heating rate and holding for a first time; then heating from the first temperature to a second temperature at a second heating rate and holding for a second time; wherein the first heating rate is ≤1℃ / min, the first temperature is 360~520℃, the first holding time is 30~120min, the second heating rate is 1~10℃ / min, the second temperature is 1140~1160℃, and the second holding time is 10~60min.

[0011] Preferably, the pore-forming agent is an acrylate copolymer, and the mass percentage of the pore-forming agent to the ceramic aggregate is 10-30%; the binder is polyvinyl alcohol, and the mass percentage of the binder to the ceramic aggregate is ≤8%.

[0012] Preferably, the porous ceramic-polymer composite material includes a first structural unit and a second structural unit. The first structural unit includes a first base layer and a plurality of sound-absorbing wedges disposed on the first base layer. The second structural unit includes a second base layer and a plurality of cavities disposed on the second base layer in a number equal to the number of sound-absorbing wedges. One sound-absorbing wedge is inserted into any one of the cavities.

[0013] The present invention provides a method for preparing the porous ceramic-polymer composite material described in the above technical solution. When the polymer matrix is ​​rubber, the method includes the following steps: mixing the porous ceramic particles and rubber in sequence and molding and vulcanizing to obtain the porous ceramic-polymer composite material. When the polymer matrix is ​​polyvinyl chloride, the process includes the following steps: mixing the polyvinyl chloride, plasticizer, stabilizer and porous ceramic particles to obtain a mixture; heating the mixture to obtain the porous ceramic-polymer composite material.

[0014] This invention provides the application of the porous ceramic-polymer composite material described in the above-described technical solution or the porous ceramic-polymer composite material prepared by the preparation method described in the above-described technical solution in sound-absorbing materials. This invention provides a porous ceramic-polymer composite material, comprising a polymer matrix and porous ceramic particles dispersed in the polymer matrix. The polymer matrix includes rubber or polyvinyl chloride (PVC). The porous ceramic particles account for 10-50% of the mass of the polymer matrix, have a porosity ≥33%, a particle size of 0.06-0.5 mm, and a pore size distribution ≥227 nm. The composite material provided by this invention, by introducing porous ceramic particles into the polymer matrix and simultaneously controlling the porosity, particle size, pore size distribution, and mass percentage of the porous ceramic particles, can significantly improve the sound absorption performance of the polymer matrix. The porous ceramic-polymer composite material provided by this invention has a wider absorption frequency band and exhibits superior sound absorption performance compared to blank polymer materials (rubber or PVC), thereby effectively reducing noise pollution.

[0015] Furthermore, the porous ceramic-polymer composite material includes a first structural unit and a second structural unit. The first structural unit includes a first base layer and a plurality of sound-absorbing wedges disposed on the first base layer. The second structural unit includes a second base layer, on which a plurality of cavities equal in number to the number of sound-absorbing wedges are disposed, and one sound-absorbing wedge is inserted into each cavity. This invention, by optimizing the structure of the composite material, can further improve its sound absorption performance. Attached Figure Description

[0016] Figure 1 For standing wave tube testing system; Figure 2 This is a schematic diagram of the test tube; Figure 3 The diagram shows the DMA performance of porous ceramic-rubber composite materials. Figure 4 This is a graph showing the effect of porosity on the sound absorption performance of composite materials. Figure 5 Analysis of the sound absorption curves of composite materials; Figure 6 Diagram of a wedge structure; Figure 7 Diagrams of wedge structures with different porosities; Figure 8 The effect of porous ceramic particle size on the sound energy absorption and sound absorption coefficient of composite materials; Figure 9 The effect of porous ceramic particle size distribution on the absorption peak frequency and half-width at half-maximum of composite materials; Figure 10 The effect of porous ceramic particle pore size on the sound energy absorption and sound absorption coefficient of composite materials; Figure 11 The effect of porous ceramic particle pore size on the absorption peak frequency and half-width at half-maximum of composite materials; Figure 12 The influence of the content of porous ceramic particles in the matrix on the sound absorption performance of composite materials; Figure 13 The effect of ceramic particle content in the matrix on the acoustic absorption peak area of ​​composite materials; Figure 14 The effect of porous ceramic particle dispersion on the sound absorption performance of composite materials; Figure 15 The dispersion of porous ceramic particles in the matrix and the area of ​​absorption peaks; Figure 16 The sound absorption curve of the composite material; Figure 17 This is a schematic diagram of the composite material structure; Figure 18 The sound absorption properties of the material in structure 1; Figure 19 A comparison of the sound absorption properties of untreated and nitrile-treated composite materials; Figure 20 This is a comparison of the sound absorption properties of the blank sample and the composite material. Detailed Implementation

[0017] This invention provides a porous ceramic-polymer composite material, comprising a polymer matrix and porous ceramic particles dispersed in the polymer matrix. The polymer matrix comprises rubber or polyvinyl chloride. The mass percentage of the porous ceramic particles in the polymer matrix is ​​10-50%. The porosity of the porous ceramic particles is ≥33%. The particle size of the porous ceramic particles is 0.06-0.5 mm. The pore size distribution of the porous ceramic particles is ≥227 nm.

[0018] In this invention, unless otherwise specified, all raw materials / components used in the preparation are commercially available products well known to those skilled in the art.

[0019] The porous ceramic-polymer composite material provided by this invention includes a polymer matrix. In this invention, the polymer matrix includes rubber or polyvinyl chloride (PVC). The rubber may be neoprene rubber.

[0020] The porous ceramic-polymer composite material provided by this invention comprises porous ceramic particles dispersed in a polymer matrix. In this invention, the porosity of the porous ceramic particles is preferably 33-63%, most preferably 33%. The particle size of the porous ceramic particles is preferably 0.06-0.3 mm. The pore size distribution of the porous ceramic particles is preferably 220-6050 nm, more preferably 227-675.2 nm.

[0021] In this invention, the method for preparing the porous ceramic particles preferably includes the following steps: This invention mixes ceramic aggregate, a pore-forming agent, and a binder to obtain a mixture. The ceramic aggregate includes kaolin, feldspar, and quartz. The mass ratio of kaolin to feldspar is 4:(3~9), and the mass ratio of kaolin to quartz is 4:(1~3). The pore-forming agent includes one or more of polyvinyl alcohol (PVA), polymethyl methacrylate (PMMA), acrylate copolymer (ACR), and polystyrene (UPS). The mass percentage of the pore-forming agent in the ceramic aggregate is 10~35%. In this invention, the feldspar is preferably albite. The quartz is preferably quartz sand. The mass ratio of kaolin to feldspar can be 4:3, 4:4, 4:5, 4:6, 4:7, 4:8, or 4:9. The mass ratio of kaolin to quartz can be 4:1, 4:2, or 4:3. The ACR is preferably ACR201. The pore-forming agent is preferably one or more of PVA, PMMA, and ACR, with ACR being the most preferred. The percentage of the pore-forming agent by mass relative to the ceramic aggregate can be 10%, 15%, 20%, 25%, or 30%. In this invention, the binder is preferably polyvinyl alcohol (PVA). The percentage of the binder by mass relative to the ceramic aggregate is preferably ≤8%, more preferably 5-8%.

[0022] In this invention, the wet mixing is preferably wet ball milling, the milling medium is preferably water, the milling balls used in the wet ball milling are preferably zirconia balls, and the particle size of the milling balls is preferably 5-10 mm. In this invention, the liquid-to-solid ratio in the wet ball milling is preferably 1:1 to 1:2, the ball-to-material ratio is preferably 3:1 to 4:1, the rotational speed of the wet ball milling is preferably 65% ​​to 80% of the critical speed, and the time of the wet ball milling is preferably ≥3 hours, more preferably 6-8 hours or ≥12 hours.

[0023] After obtaining the mixture, the present invention presses the mixture into a molded body. In the present invention, the pressing pressure is preferably 15~25MPa, and in the embodiments it can be 20MPa or 25MPa. The holding time of the pressing is preferably 3~8min, and in the embodiments it can be 5min.

[0024] After obtaining the molded body, the present invention sequentially dries, crushes, and sieves the molded body to obtain ceramic particles. In the present invention, the drying temperature is preferably ≤100℃. The drying process preferably includes pre-drying and high-temperature drying sequentially. The pre-drying temperature is preferably 20~30℃, and the pre-drying time is preferably 24 hours. The high-temperature drying temperature is preferably 100℃, and the pre-drying time is preferably ≥12 hours. The specific implementation process of the crushing is not particularly required in the present invention, and the sieve used for screening after crushing is preferably 2000~2500 mesh.

[0025] After obtaining ceramic particles, the present invention sintersulates the ceramic particles to obtain the porous ceramic material. The sintering includes the following steps: heating to a first temperature at a first heating rate and holding for a first time; then heating from the first temperature to a second temperature at a second heating rate and holding for a second time; the first heating rate is ≤1℃ / min, the first temperature is 360~520℃, and the second temperature is 1140~1160℃. In the present invention, it is preferred to heat from room temperature to the first temperature at the first heating rate, and the room temperature is preferably 20~30℃. The first heating rate is preferably 1℃ / min. The first temperature is preferably 520℃. The first holding time is preferably 30~120min, and in the embodiment, it can be 120min. The second heating rate is preferably 1~10℃ / min, more preferably 5~10℃ / min, and in the embodiment, it can be 5℃ / min. The second temperature (hereinafter referred to as the firing temperature) is preferably 1160℃. The second holding time is preferably 10~60min, more preferably 60min.

[0026] In the porous ceramic-polymer composite material provided by the present invention, the mass percentage of the porous ceramic particles to the mass of the polymer matrix is ​​10-50%, preferably 10%.

[0027] In this invention, when the polymer matrix is ​​rubber, the porous ceramic particles are modified porous ceramic particles, specifically porous ceramic particles with a nitrile rubber surface modified. The preferred method for preparing the nitrile rubber surface-modified porous ceramic particles includes impregnating the porous ceramic particles with a nitrile rubber solution to obtain impregnated porous ceramic particles; and drying the impregnated porous ceramic particles to obtain the nitrile rubber surface-modified porous ceramic particles. Before impregnation, the present invention preferably pre-treats the porous ceramic particles, the pre-treatment preferably including sequential washing, drying, and activation treatments, wherein the washing reagent is preferably alcohol. The drying temperature after washing is preferably 100~150℃. The activation treatment preferably uses a silane coupling agent to treat the surface of the porous ceramic particles, and the silane coupling agent can be KH550.

[0028] In this invention, the nitrile rubber solution is preferably an ethyl acetate solution of nitrile rubber. The mass percentage of nitrile rubber in the ethyl acetate solution is preferably 5-8%. The impregnation time is preferably 1.5-2 hours, and the impregnation is carried out under stirring conditions. After impregnation, the obtained impregnated porous ceramic particles are removed from the solution, air-dried, and finally dried in an oven at a temperature preferably 60-80°C.

[0029] In this invention, the structure of the porous ceramic-polymer composite material is preferably as follows: Figure 17 As shown in the right figure below. Figure 17 The right figure illustrates in detail the structure of the porous ceramic-polymer composite material provided by this invention. The porous ceramic-polymer composite material preferably includes a first structural unit and a second structural unit. The first structural unit includes a first base layer and a plurality of sound-absorbing wedges disposed on the first base layer. The second structural unit includes a second base layer, on which a plurality of cavities equal in number to the number of sound-absorbing wedges are disposed, with one sound-absorbing wedge inserted into each cavity. The first structural unit is disposed above the second structural unit, with the sound-absorbing wedges of the first structural unit facing downwards. The cavities of the second structural unit open upwards. The top of each sound-absorbing wedge has a conical structure. The depth of each cavity is greater than the height of the sound-absorbing wedge. The width of each cavity is greater than the width of the sound-absorbing wedge.

[0030] This invention provides a method for preparing the porous ceramic-polymer composite material described in the above-mentioned technical solution. In this invention, when the polymer matrix is ​​rubber, the method for preparing the porous ceramic-polymer composite material includes the following steps: sequentially mixing the porous ceramic particles and rubber, and then performing compression molding and vulcanization to obtain the porous ceramic-polymer composite material. In this invention, the rubber preferably comprises the following components in parts by weight: 100 parts of chloroprene rubber raw rubber, 5 parts of zinc oxide, 4 parts of magnesium oxide, 2 parts of antioxidant, 10 parts of plasticizer, and 25 parts of carbon black. The antioxidant can be 4020. The plasticizer can be naphthenic oil. The mixing is preferably carried out in a two-roll mill, and the compression molding and vulcanization is preferably carried out in a flat vulcanizing agent. The compression molding and vulcanization conditions preferably include: a temperature preferably of 150°C and a time preferably of 20-30 minutes.

[0031] In this invention, when the polymer matrix is ​​polyvinyl chloride (PVC), the preparation method of the porous ceramic-polymer composite material includes the following steps: mixing the PVC, plasticizer, stabilizer, and porous ceramic particles to obtain a mixture; and heating the mixture to obtain the porous ceramic-polymer composite material. In this invention, the plasticizer is preferably dioctyl phthalate (DOP). The stabilizer preferably includes lead sulfate (trisal salt) and lead phosphite (disalt). In this invention, the mixing preferably includes: stirring and mixing the PVC, plasticizer, and stabilizer to obtain a PVC paste; and mixing the PVC paste with the porous ceramic particles to obtain a mixture. The heating treatment preferably includes: subjecting the mixture to a first heating treatment to obtain a thickening material; and subjecting the thickening material to a second heating treatment to obtain the porous ceramic-polymer composite material. The temperature of the first heating treatment is preferably 100°C, and the time is preferably 1-2 minutes. The temperature of the second heating treatment is preferably 200°C, and the time is preferably 15-18 minutes.

[0032] This invention provides the application of the porous ceramic-polymer composite material described in the above-described technical solution or the porous ceramic-polymer composite material prepared by the preparation method described in the above-described technical solution in sound-absorbing materials.

[0033] In this invention, the porous ceramic-polymer composite material is preferably used in underwater sound-absorbing materials. The preferred environment for this application is an underwater environment, and the preferred water pressure during application is 1~2.5 MPa.

[0034] To further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0035] The standing wave tube tests performed in the following examples: Adopting such Figure 1 The standing wave tube testing system shown was used to determine the sound absorption properties of a small porous ceramic-rubber composite sample. The sample was placed as follows. Figure 2 As shown.

[0036] The underwater acoustic testing system used in the following embodiments: The underwater acoustic absorption and sound insulation performance of a large sample was determined using the 208 acoustic tube testing system from the Marine Systems Engineering Department and the one-way receiving method.

[0037] Example 1: This embodiment provides a method for preparing porous ceramic particles. The raw materials for preparing porous ceramic particles in this embodiment include ceramic aggregate, pore-forming agent, and binder. The ceramic aggregate consists of kaolin, albite, and quartz, and the mass ratio of kaolin, albite, and quartz to kaolin is 4:4:1, 4:5:1, 4:6:1, 4:7:1, or 4:4:2. The pore-forming agent is ACR, and the mass percentage of ACR to the ceramic aggregate is 20%, 25%, 30%, or 35%. The binder is PVA, and the mass percentage of the binder to the ceramic aggregate is 8%.

[0038] The preparation method is as follows: Ceramic aggregate, pore-forming agent, and PVA were added to water and milling balls for 6 hours to obtain a mixture. The mixture was then compressed into tablets. The pressure was maintained at 20 MPa for 5 minutes, and then released slowly to avoid internal cracking. The compressed tablets were then air-dried for 24 hours, and finally placed in a drying oven at 100℃ for 24 hours to remove excess moisture. A molded body was obtained. The molded body was crushed and sieved to obtain ceramic particles. The ceramic particles were heated from room temperature to 520℃ at a rate of 1℃ / min and held for 120 minutes. Then, the temperature was further increased to 1160℃ at a rate of 5℃ / min and held for 60 minutes to obtain porous ceramic particles. In this embodiment, the mass ratio of kaolin, albite, and quartz to kaolin is 4:5:1 or 4:4:2. The mass percentage of ACR to the ceramic aggregate is 20%, 25%, 30%, and 35%, respectively, resulting in porous ceramic particles with porosities of 33%, 43%, 51%, and 63%. Specific data for the porous ceramic particles prepared in this embodiment are shown in Table 1.

[0039] Example 2: This embodiment provides a method for preparing a porous ceramic-rubber composite material. The raw materials used include porous ceramic particles prepared in Example 1 and chloroprene rubber. The chloroprene rubber includes the following components in parts by weight: 100 parts of chloroprene rubber raw rubber, 5 parts of zinc oxide, 4 parts of magnesium oxide, 2 parts of antioxidant 4020, 10 parts of plasticizer (naphthenic oil), and 25 parts of carbon black.

[0040] Includes the following steps: First, the chloroprene rubber raw rubber was plasticized, then magnesium oxide, antioxidant 4020 and half the mass of carbon black were added and thoroughly mixed. After that, the remaining carbon black and plasticizer were added, then the porous ceramic prepared in Example 1 was added and thoroughly mixed. Finally, zinc oxide was added. The roller temperature was controlled not to exceed 90°C and the mixing time was not to exceed 10 minutes throughout the mixing process to obtain the compound. The compound was then subjected to compression molding vulcanization using a flat vulcanizing agent (150°C × 20 minutes) to obtain a porous ceramic-rubber composite material. The porous ceramic-rubber composite material prepared in this example was a sample with a diameter of 28.5 mm and a thickness of 12.5 mm.

[0041] Example 3: This embodiment provides a method for preparing porous ceramic-PVC composite material, including the following steps: Polyvinyl chloride, dioctyl phthalate, tris(lead sulfate), and dis(lead phosphite) were vigorously stirred to obtain a PVC paste. The PVC paste was then mixed with the porous ceramic particles prepared in Example 1 to obtain a PVC paste / solid porous ceramic particle mixture. The PVC paste / solid porous ceramic particle mixture was first heated to 100°C and held for 1 minute to thicken it, and then heated to 200°C and held for 15 minutes to obtain a porous ceramic-PVC composite material. The porous ceramic-PVC composite material prepared in this example has a diameter of 28.5 mm and a thickness of 12.5 mm.

[0042] This invention uses a standing wave tube to measure the sound absorption properties of the composite materials prepared in Examples 2 and 3. The effects of particle size, porosity, pore size, content, and pore distribution uniformity of porous ceramics on the sound absorption properties of the porous ceramic / polymer composite materials were investigated.

[0043] Test Example 1: Performance Testing of Porous Ceramic-Rubber Composite Materials In Example 1 of this invention, porous ceramic particles with porosities of 33%, 43%, 51%, and 63% were prepared by using pore-forming agent ACR with contents of 20wt%, 25wt%, 30wt%, and 35wt%. Furthermore, porous ceramic particles with different pore sizes were prepared by using ceramic powder ratios of 4:5:1 and 4:4:2. These particles were then composited with rubber. The physical properties of the obtained porous ceramic particles are shown in Table 1.

[0044] Table 1. Physical properties of porous ceramic-rubber composites with different porosities prepared in Examples 1 and 2.

[0045] Table 1 shows that the porous ceramic particles prepared with a kaolin, albite, and quartz mass ratio of 4:5:1 have a wider pore size distribution than those prepared with a ratio of 4:4:2. Furthermore, porous ceramic particles with a gradient porosity distribution were obtained at different ACR mass contents. The density, strength, and Shore A hardness of the four porous ceramic-rubber composites with different porosities were not significantly different. Regarding elongation at break, except for the composite with a porosity of 51%, which showed a significant difference from the other three, the other three samples were similar.

[0046] Influence of porosity and pore size on the sound absorption properties of porous ceramic-rubber composites This invention uses porous ceramic particles prepared in Example 1 as raw materials to compare the effect of porosity on the sound absorption performance of porous ceramic-rubber composite materials. The blank sample is a pure rubber sample without the addition of porous ceramic particles. Figure 3 The DMA properties of porous ceramic-rubber composites. From Figure 3 As can be seen, the loss factor of the composite material gradually increases with increasing porosity, while the proportion has little effect. That is, the most important influencing factor in DMA performance is the porosity of the porous ceramic particles. Furthermore, the full width at half maximum (FWHM) of the loss factor widens. The loss factor is a parameter characterizing the viscoelasticity of a material, primarily reflecting the sound absorption performance of the rubber matrix. Increased porosity facilitates vibration and energy absorption within the rubber matrix, thus increasing the loss factor. Below are the sound absorption data of the composite material measured using a standing wave tube. Figure 4 The effect of porosity on the sound absorption performance of porous ceramic-rubber.

[0047] from Figure 4 As can be seen, for porous ceramic-rubber composites with the same ceramic aggregate mass ratio, the frequency at which the composite material has the maximum sound absorption coefficient (hereinafter referred to as the maximum sound absorption frequency) shifts towards higher frequencies as the porosity increases. Figure 4 In the left figure, the maximum sound absorption frequency of the porous ceramic-rubber composite material shifts from 4243Hz to 5142Hz; Figure 4 In the right figure, the maximum sound absorption frequency of the porous ceramic-rubber composite material shifts from 3554Hz to 5498Hz. Table 2 shows the data analysis of the obtained sound absorption curves. Figure 5 Analysis of sound absorption curves for porous ceramic-rubber composite materials. Figure 5 The left figure shows the change in absorption peak area with porosity. Figure 5 The right figure shows the variation of the maximum absorption peak frequency and the sound absorption coefficient with the average pore size.

[0048] Table 2. Sound absorption curve analysis of porous ceramic-rubber composite materials

[0049] As shown in Table 2, the absorption peak area of ​​the resulting porous ceramic-rubber composite material gradually decreases with increasing porosity of the porous ceramic particles. This is mainly because, during the compounding process of porous ceramic particles and rubber (mixing on a two-roll mill), a portion of the rubber matrix is ​​squeezed into the pores of the porous ceramic, forming a wedge resonance structure. Figure 6 (Diagram of a wedge structure). When sound waves enter the rubber, they cause the wedge-shaped rubber to vibrate, which in turn causes the air between the pore walls and the rubber to vibrate. This structure is more conducive to the dissipation of sound energy.

[0050] Figure 7 The diagram shows wedge structures with different porosities. At low porosities, the spacing between pores in porous ceramics is relatively large, making it easier to form... Figure 7 The structure in the left image shows that, under high porosity conditions, this spacing decreases, making it easier for pores to form co-pores. These pores make it difficult for rubber to enter, resulting in a structure like... Figure 7 The structure in the right figure. Comparing the two, it is obvious that... Figure 7 The structure shown in the left figure has better sound absorption performance than... Figure 7 The structure is shown in the right figure. Therefore, as the porosity increases, the absorption peak area of ​​the porous ceramic-rubber composite material actually decreases.

[0051] As can be seen from Table 2, the maximum sound absorption coefficient of the porous ceramic-rubber composite material gradually increases with the increase of the average pore size of the porous ceramic particles. Except for the material with a pore size of 13164.9 nm (i.e., a porosity of 63%), the maximum absorption frequency of the other three materials shifts to lower frequencies with the increase of the average pore size. Maximum resonant frequency f c It can be estimated using 0.2×C / L. Where C represents the speed of sound and L represents the length of the wedge tip. As the aperture increases, the length of the wedge squeezed into the porous ceramic pores increases, thus the maximum resonant frequency gradually decreases, i.e., it shifts to lower frequencies.

[0052] Test Example 2: Sound Absorption Performance of Porous Ceramic-PVC Composite Material Porous ceramic particles were added to PVC according to the preparation method in Example 3 to prepare a porous ceramic-PVC composite material. The effects of particle size distribution, pore size distribution, content and dispersion uniformity of porous ceramic particles on the sound absorption performance of the porous ceramic-PVC composite material were studied.

[0053] (1) Effect of particle size distribution of porous ceramic particles on the sound absorption performance of porous ceramic-PVC composite material The porous ceramic formulation was chosen as kaolin:albite:quartz sand 4:4:2, with 30wt% pore-forming agent ACR added, and porous ceramic particles were prepared according to the method described in Example 1. The sintered porous ceramic particles were then mixed with PVC to prepare a composite sound-absorbing material. Figure 8 The effect of porous ceramic particle size on the sound energy absorption and sound absorption coefficient of porous ceramic-PVC composite materials. Figure 9 The effect of porous ceramic particle size distribution on the absorption peak frequency and half-width at half-maximum of porous ceramic-PVC composite materials.

[0054] Depend on Figure 8 As can be seen, within a specific frequency range, the sound absorption coefficient is the largest when the particle size is between 0.06 and 0.5 mm, the smallest when the particle size is between 0.3 and 0.5 mm, and the sound absorption coefficient is in between when the particle size is between 0.06 and 0.3 mm.

[0055] Because when the particle size of porous ceramic particles is distributed between 0.06 and 0.5 mm, the relative number of various pore sizes increases, enabling the absorption of more sound waves, thus resulting in the highest sound absorption coefficient. The sound absorption coefficient is larger for particles with a size between 0.06 and 0.3 mm than that for particles with a size between 0.3 and 0.5 mm. This is because, for samples under the same conditions, smaller ceramic particle sizes allow for easier and more uniform mixing with the PVC matrix, resulting in smaller pores within the composite material, i.e., higher flow resistance and better sound absorption. Conversely, as the particle size increases, the mixing with the PVC matrix deteriorates, the porosity within the composite material increases, i.e., lower flow resistance and worse sound absorption.

[0056] Integrating the sound absorption coefficient curves of each composite material ( Figure 8 It was found that the composite material absorbed the most sound energy when the particle size of the porous ceramic particles was 0.06~0.3mm, and the composite material absorbed the least sound energy when the particle size of the porous ceramic particles was 0.06~0.5mm.

[0057] like Figure 9 The composite material with porous ceramic particles of 0.06~0.5mm in diameter exhibits the smallest half-width at half-maximum (WHM) of its absorption peak and a narrower sound absorption frequency range. The composite materials filled with porous ceramic particles of the other two particle sizes show wider WHMs and broader sound absorption frequency ranges. However, the absorption peak frequency of the composite material remains unchanged.

[0058] In summary, porous ceramic-PVC composite materials exhibit the best sound absorption performance when the particle size of porous ceramic particles is 0.06~0.3mm; they have a wide absorption frequency band of 547; absorb the most energy of 753; and also have a high sound absorption coefficient of α=0.819.

[0059] (2) Influence of pore size of porous ceramic particles on the sound absorption performance of porous ceramic-PVC composite material Porous ceramic particles with different pore sizes were prepared according to the specified ratios, and then composited with PVC to study the effect of pore size on the sound absorption performance of the composite material. Table 3 shows the pore size data of the porous ceramic particles prepared in Example 1 under different mass ratios of kaolin, albite, and quartz. After compositing the porous ceramic particles with different pore sizes with a PVC matrix to form a composite material, Figure 10 The effect of porous ceramic particle pore size on the sound energy absorption and sound absorption coefficient of porous ceramic-PVC composite material. Figure 11 The effect of porous ceramic particle pore size on the absorption peak frequency and half-width at half-maximum of porous ceramic-PVC composite material.

[0060] Table 3 Porous ceramic formulations and pore sizes

[0061] from Figure 10 As can be seen, within a certain frequency range, the sound absorption coefficient of porous ceramic-PVC composite materials filled with porous ceramic particles decreases with increasing pore size. The sound absorption coefficient of the porous ceramic-PVC composite material is 0.526 when the pore size distribution is 1051~6023.7nm, 0.500 when it is 834.1~1608nm, 0.612 when it is 227~675.2nm, and 0.709 when it is 6~13.7nm.

[0062] Within a specific frequency range, the sound absorption coefficient of porous ceramic-PVC composite materials tends to increase with decreasing pore size. This is partly because as the pore size decreases, the flow resistance of the sample increases, causing more energy to be absorbed and converted into heat as sound waves pass through the pores, resulting in greater sound wave attenuation. On the other hand, the pore size distribution becomes more concentrated, making the absorption of sound waves at specific frequencies more significant. Therefore, smaller pore sizes generally result in higher sound absorption coefficients.

[0063] The sound absorption coefficient of porous ceramic-PVC composites with a pore size distribution of 1051~6023.7nm is larger than that with a pore size distribution of 834.1~1608nm. This may be because the larger pore size leads to the formation of secondary structures inside the pores, which increases the roughness and improves the viscosity of the air in the pores, thus enhancing the viscous absorption effect.

[0064] For each line integral, such as Figure 10 As shown, the porous ceramic-PVC composite material with a pore size of 227~675.2nm absorbs the most energy, with an absorption peak integral area of ​​718; while the porous ceramic-PVC composite material with a pore size of 6~13.7nm absorbs the least energy, with an absorption peak integral area of ​​636. This is because as the pore size increases, the number of reflections of sound waves inside the pores increases, and the path lengthens, thus consuming energy in the process.

[0065] like Figure 11 As shown, changes in the pore size of porous ceramics do not affect the absorption peak frequency. However, as the pore size decreases, the full width at half maximum (FWHM) of the absorption peak in the porous ceramic-PVC composite material narrows.

[0066] Therefore, in summary, for porous ceramics, the pore size should be controlled within a reasonable range. If the pore size is too small, although the absorption coefficient is large, the absorption frequency range is too narrow; if the pore size is too large, although the absorption peak width is increased, the sound absorption coefficient is affected.

[0067] (3) The effect of the content of porous ceramic particles in PVC on the sound absorption performance of composite materials Considering the influence of albite on the pore size of porous ceramics, Example 1 uses a porous ceramic material with a ratio of kaolinite:albite:quartz sand of 4:4:1 and 20% ACR as a pore-forming agent to prepare a porous ceramic-PVC composite material. Figure 12 The influence of the content of porous ceramic particles in the matrix on the sound absorption performance of porous ceramic-PVC composite materials. Figure 13 The effect of the content of ceramic particles in the matrix on the acoustic absorption peak area of ​​porous ceramic-PVC composite materials.

[0068] from Figure 12 As can be seen, when the porosity of the ceramic particles is the same, within a certain frequency range, when the content of ceramic particles in the PVC matrix is ​​within 0~10%, the absorption peak frequency and sound absorption coefficient of the porous ceramic-PVC composite material increase with the increase of the ceramic particle content. When the ceramic particle content is greater than 10%, the absorption peak frequency of the porous ceramic-PVC composite material is the largest, at 2000Hz, and the sound absorption coefficient is also the largest, at 0.626. When the ceramic particle content is within 10~50%, the absorption peak frequency of the porous ceramic-PVC composite material remains unchanged at 1600Hz, while the sound absorption coefficient decreases.

[0069] When the content of porous ceramic particles in the PVC matrix is ​​low, the sound absorption performance of the porous ceramic-PVC composite material is primarily determined by the PVC matrix, with the porous ceramic particles playing a secondary role. The sound absorption properties of the porous ceramics themselves have a stronger effect on optimizing the sound absorption performance of the porous ceramic-PVC composite material than on degrading the sound absorption performance of the PVC matrix. Therefore, when the porous ceramic content is less than 10%, the sound absorption coefficient of the porous ceramic-PVC composite material increases with increasing porous ceramic content. When the porous ceramic content is greater than 10%, the degrading effect of the porous ceramics on the sound absorption performance of the PVC matrix is ​​stronger than its optimizing effect on the porous ceramic-PVC composite material. Therefore, the sound absorption coefficient of the composite material gradually decreases with increasing porous ceramic content.

[0070] When the content of porous ceramic particles in the PVC matrix is ​​less than 10%, the porous ceramic particles increase the melting temperature of the PVC matrix. As the content increases, the melting temperature of the porous ceramic-PVC composite increases, and the sound absorption frequency also increases. When the content of porous ceramic particles is greater than 10%, the sound absorption frequency of the porous ceramic-PVC composite initially decreases slightly with increasing content, and then remains constant. This is because porous ceramics play a dominant role in sound absorption, and the sound absorption frequency of porous ceramics is relatively low.

[0071] At the same time, for each curve integral ( Figure 13 It was found that the porous ceramic-PVC composite material had the largest integral area, meaning it absorbed the most energy, when filled with 10% porous ceramic particles. Adding 20%, 30%, 40%, and 50% porous ceramic particles respectively did not significantly change the overall sound absorption energy.

[0072] Therefore, for porous ceramic particles with the same porosity, there is an appropriate range for their content in the same matrix; too high or too low a content is not suitable. The composite material exhibits the best sound absorption performance when filled with 10% porous ceramic particles. The sound absorption coefficient is 0.626, the absorbed sound energy is 839, and the absorption peak half-width is 812 Hz.

[0073] (4) The effect of the dispersibility of porous ceramic particles in PVC on the sound absorption performance of composite materials Because the compatibility between porous ceramic particles and the matrix is ​​poor and the specific gravity differs greatly during the preparation of PVC-based porous ceramic composite sound-absorbing materials, stratification is prone to occur during the plasticization process. This results in uneven mixing of porous ceramic particles in the matrix, which may affect the sound absorption performance of the composite material. Figure 14 and Figure 15 To investigate the effect of porous ceramic particle dispersion on the sound absorption performance of porous ceramic-PVC composite materials, Figure 14 The porous ceramic particles in the material have a particle size of 0.3~0.5mm. Figure 15 The dispersion and absorption peak area of ​​porous ceramic particles in PVC matrix.

[0074] Depend on Figure 14 As can be seen, within a certain frequency range, when the matrix and the porosity of the porous ceramic particles are the same, the sound absorption coefficient of the composite material with uniformly dispersed ceramic particles mixed into the matrix is ​​higher than that of the non-uniformly dispersed composite material. Simultaneously, its absorption peak half-width (FWHM) narrows and shifts towards lower frequencies. Conversely, with non-uniform dispersion, the absorption coefficient decreases, the FWHM widens, and it shifts towards higher frequencies.

[0075] Because the better the uniformity of particle dispersion, the better the matrix's coverage of the dispersed phase, and the more uniform and complete it is, the higher the sound absorption coefficient. Non-uniform dispersion of the dispersed phase produces agglomerates, which indirectly increases the porosity, i.e., the gaps between particles. Moreover, the size of these gaps is small, and the corresponding sound wavelength is short, which manifests as a broadening of the absorption peak while shifting towards higher frequencies.

[0076] Figure 15 As shown, the composite material absorbs the most sound energy when porous ceramic particles are not uniformly dispersed in the matrix.

[0077] Figure 16 This study compares the sound absorption properties of porous ceramic-rubber composites and porous ceramic-PVC composites. From... Figure 16 As can be seen, when the porosity is 43%, 51%, and 63%, the sound absorption frequency range of both types of composite materials tends to shift towards higher frequencies with increasing porosity. Table 4 shows the data analysis of the two sound absorption curves: Table 4. Sound absorption curve analysis of composite materials

[0078] Table 4 shows that, firstly, regarding the porous ceramic-rubber composite material, in terms of the change in sound absorption frequency band, within the porosity range of 43% to 63%, as the porosity increases, the frequency band with sound absorption performance (i.e., sound absorption coefficient > 0.2) gradually shifts towards higher frequencies. Its sound absorption area and half-peak width are both largest with a porosity of 33%, exhibiting excellent sound absorption effects in the frequency range of 3342–5493 Hz. In terms of the maximum sound absorption coefficient, the composite material with a porosity of 43% has the highest, reaching 0.99, almost completely absorbing sound energy, with its sound absorption frequency band mainly concentrated in the range of 2823–4468 Hz.

[0079] Compared with the blank sample (rubber matrix), the composite material with a porosity of 33% has better sound absorption peak area and half-width at half-maximum. The absorption peak areas of 43% and 51% are larger than those of the blank sample, and the maximum sound absorption coefficients of 43% and 63% are significantly higher than those of the blank sample. Therefore, the addition of porous ceramics improves the sound absorption performance of the rubber matrix in different aspects.

[0080] The sound absorption area reflects the sound absorption effect of a material across the entire frequency band. Therefore, to achieve a good overall sound absorption effect, porous ceramic particles with a porosity of 33% should be added; while to achieve a good sound absorption effect in a slightly lower and narrower frequency range, particles with a porosity of 43% should be added.

[0081] Looking at the porous ceramic-PVC composite material, the variation in sound absorption frequency bands shows a pattern very similar to that of the porous ceramic-rubber composite material. Both the absorption peak area and the maximum sound absorption coefficient are highest at a porosity of 63%. Its half-peak width is not significantly different from the other samples.

[0082] Compared with the blank sample (PVC matrix), the porous ceramic-PVC composite material showed significant improvements in both absorption peak area and maximum sound absorption coefficient. However, the difference in half-width at half-maximum (WHM) was not substantial.

[0083] Therefore, the addition of porous ceramic particles improves the sound absorption performance of the original PVC material. Furthermore, among the various methods, the composite material with the addition of porous ceramic particles with a porosity of 63% exhibits the best sound absorption performance.

[0084] Example 4: Porous ceramic particles were prepared using a ceramic aggregate ratio of 4:4:2 (kaolin:albite:quartz), ball-milled for 6 hours, with an ACR content of 30 wt%, under the sintering regime of Example 1. The obtained porous ceramic particles were then composited with rubber to prepare samples with a diameter of 120 mm and a thickness of 40 mm. In this example, to increase the bonding strength between the porous ceramic particles and the rubber, the surface of the porous ceramic particles was treated with a nitrile rubber solution to obtain nitrile rubber-modified porous ceramic particles.

[0085] Methods for preparing porous ceramic particles modified with nitrile rubber include: (1) Pretreatment of porous ceramic particles: Use alcohol to clean and remove dust, impurities and other contaminants from the surface, then dry them in a high-temperature oven at 100~150℃, and then use KH550 to activate the surface. (2) Prepare an ethyl acetate solution of nitrile rubber with a mass concentration of 5%~8% for later use; (3) Immerse the pretreated porous ceramic particles from step (1) in the nitrile rubber solution from step (2), and stir thoroughly to ensure full wetting and penetration. The mixing time is generally 1.5 to 2 hours. (4) Transfer the treated porous ceramic particles to a fume hood to allow most of the solvent to evaporate naturally; then place them in an oven and dry them at 60~80℃ to completely remove the residual solvent. (5) The particles processed in step (4) are sieved (2000 mesh or 2500 mesh) to break up any soft agglomerates that may be formed due to adhesion, and porous ceramic particles with modified nitrile rubber surface are obtained.

[0086] Porous ceramic-rubber composites and nitrile-treated porous ceramic-rubber composites were prepared according to Example 2. The prepared porous ceramic particles were then added to two rubber materials with different structures: Structure 1 and Structure 2, as shown below. Figure 17 As shown, Figure 17 The left diagram shows the structure of Structure 1, which is a composite material containing wedges. Figure 17 The right figure shows structure 2, which is a two-layer composite material. The underwater acoustic absorption performance of the two different composite materials was tested using a passive underwater acoustic pulse tube method measurement system. The sound absorption performance of the composite material and pure rubber samples (hereinafter referred to as blank samples) were measured at different frequencies (3~8kHz) and different pressures (0.5~3.0MPa).

[0087] (1) Influence of porous ceramic particles on the sound absorption performance of composite material of structure 1 The effect of adding porous ceramic particles on the sound absorption performance of the composite material of structure 1 is as follows: Figure 18 As shown.

[0088] from Figure 18 As can be seen from the figure, under structure 1 and water pressures ranging from 0.5 to 3.0 MPa, the sound absorption performance of the composite material gradually decreases with increasing pressure, which is consistent with the trend of the blank sample. At each pressure, the changes in the sound absorption performance of the composite material at different frequencies are also consistent with the blank sample, indicating that the addition of porous ceramic particles forms a resonant structure with the rubber matrix, thus causing the two samples to show the same trend. The figure also shows that at each frequency, the addition of porous ceramic particles reduces the sound absorption performance of the composite material compared to the blank sample. This may be because, under this structure, the addition of porous ceramic particles disrupts the original structure of the rubber matrix. Although the porous ceramic and rubber form a resonant sound absorption structure, the destructive effect is greater than the resonant effect, thus reducing the sound absorption performance of the composite material.

[0089] Because the sound absorption performance of the composite material obtained by adding porous ceramic particles is poor, the surface of the porous ceramic particles is treated with a nitrile rubber solution, and then it is compounded with rubber. The properties of the resulting material are as follows: Figure 19 As shown. Figure 19 This is a comparison of the sound absorption properties of untreated and nitrile-treated composite materials.

[0090] Figure 19 The Y-axis represents the average sound absorption coefficient under water pressure ranging from 0.5 to 3 MPa. From... Figure 19 As can be seen, the composite material of porous ceramic particles and rubber treated with nitrile rubber solution exhibits slightly better performance than the untreated composite material. This is because treating the surface of the porous ceramic particles with nitrile rubber optimizes the bonding between the porous ceramic particle surface and the rubber matrix to a certain extent. Therefore, the addition of porous ceramic particles has less destructive effect on the structure than untreated porous ceramic particles, resulting in slightly better sound absorption performance.

[0091] (2) Influence of porous ceramic particles on the sound absorption performance of composite material of structure 2 Untreated porous ceramic particles were added to the rubber matrix of structure 2, and the sound absorption properties of the blank sample and the composite material were measured in the water pressure range of 0.5~3MPa and the frequency range of 3~8kHz. The obtained sound absorption curves are shown below. Figure 20 As shown. Figure 20 This is a comparison of the sound absorption properties of the blank sample and the composite material.

[0092] from Figure 20 As can be seen, the sound absorption performance of the composite material in structure 2 is better than that in structure 1. This is mainly because, compared with structure 1, the contact area between air and composite material in structure 2 is increased, thereby increasing the friction between the composite material and air interface. At the same time, more sound waves are incident into the interior of the material, which increases resonant sound absorption, resulting in better overall sound absorption performance of the material.

[0093] from Figure 20 It can also be seen that as the water pressure increases from 0.5 to 3.0 MPa, the sound absorption performance of both the composite material and the blank sample gradually decreases and the difference gradually increases in the frequency band of 3 to 5 kHz: in the range of 0.5 to 1.5 MPa, the sound absorption performance of the two is similar, while in the range of 2.0 to 3.0 MPa, the sound absorption performance of the blank sample is better than that of the composite material.

[0094] In the 5-8kHz frequency band, as the water pressure increases, the difference in sound absorption performance between the composite material and the blank sample shows a trend of first increasing and then decreasing. Moreover, in the pressure range of 1.0-2.0MPa, the sound absorption performance of the composite material is much better than that of the blank sample.

[0095] For the blank sample, at high frequencies, the vibration frequency of the sound wave is high. As the water pressure increases, the internal friction between the rubber macromolecular chains increases, and more sound energy is converted into heat energy and consumed. In the low-frequency range, the vibration frequency of the sound wave is low, and the effect of increased water pressure on its sound absorption performance is not significant. When the pressure increases to a certain value, the increased water pressure makes the friction between the rubber macromolecular chains even greater, resulting in slower movement of rubber molecules and a decrease in the sound absorption coefficient.

[0096] For composite materials, as water pressure increases, the speed of sound wave transmission increases. At higher frequencies, this leads to more frequent resonance between the rubber and porous ceramics, causing more sound energy to be converted into heat energy. Increased resonance absorption results in an increased sound absorption coefficient. However, when the water pressure increases to a certain level, the friction between the molecules within the rubber becomes too great, and the strain can no longer keep up with the stress changes, weakening the resonance effect and thus reducing the sound absorption performance. On the other hand, the pore wall strength of the added porous ceramic particles cannot withstand excessive pressure; therefore, when the water pressure increases to 2.5 MPa, the sound absorption performance of the composite material begins to decline.

[0097] Therefore, for structure 2, the addition of porous ceramic particles can improve the sound absorption effect of the composite material when the water pressure is between 1 and 2.5 MPa.

[0098] As can be seen from the above embodiments, the addition of porous ceramic particles in this invention greatly affects the sound absorption performance of polymer materials; porosity is an important factor affecting the sound absorption performance of composite materials, and porosity has a similar effect on the sound absorption frequency band of porous ceramic-rubber composite materials and porous ceramic-PVC composite materials.

[0099] This invention has found that higher porosity does not necessarily mean better sound absorption performance in composite materials. In this invention, for porous ceramic-rubber composite materials, the addition of porous ceramic particles with a porosity of 33% yields the best overall sound absorption performance. This invention reveals that the addition of porous ceramic particles can improve the sound absorption performance of PVC matrix materials. The particle size distribution, pore size distribution, addition amount, and dispersion uniformity of the porous ceramic particles all affect the sound absorption performance of porous ceramic-PVC. When the particle size distribution of the porous ceramic particles is 0.06~0.3mm, the composite material exhibits the best sound absorption performance, with a wide absorption frequency range (547nm), the highest absorbed energy (753nm), and a relatively high sound absorption coefficient (α=0.819). When the pore size distribution of the porous ceramic particles is 227~675.2nm, the composite material exhibits the best sound absorption performance, with a sound absorption coefficient of 0.612, absorbed sound energy of 718nm, and a half-maximum width at half-maximum (FWHM) of 746. If the pore size is too small, although the absorption coefficient is high, the absorption frequency range is too narrow; if the pore size is too large, although the absorption peak width increases, the sound absorption coefficient is affected. The composite material exhibits the best sound absorption performance when the addition amount of porous ceramic particles is 10%. The sound absorption coefficient is 0.626, the absorbed sound energy is 839, and the half-width at half-maximum (WHM) of the absorption peak is 812 Hz. When porous ceramic particles are non-uniformly dispersed in the matrix, the WHM of the composite material is wider and the frequency band is broader than that of uniformly dispersed particles.

[0100] This invention demonstrates that adding porous ceramic particles to composite materials with different structures will result in different sound absorption effects. The addition of porous ceramic particles improves the sound absorption performance of the composite material of structure 2 to a certain extent.

[0101] This invention uses a nitrile rubber solution to treat the surface of porous ceramic particles, which can increase the bonding between the porous ceramic particles and the rubber and improve the resonance sound absorption effect.

[0102] This invention improves the sound absorption effect of porous ceramic-rubber composite materials by increasing water pressure within a certain range; however, if the water pressure exceeds the tolerance of the porous ceramic particle pore walls, the sound absorption performance of the composite material decreases. Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. Other embodiments can be obtained based on these embodiments without creative intent, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A porous ceramic-polymer composite material, characterized in that, The invention comprises a polymer matrix and porous ceramic particles dispersed in the polymer matrix. The polymer matrix includes rubber or polyvinyl chloride. The porous ceramic particles account for 10-50% of the mass of the polymer matrix. The porosity of the porous ceramic particles is ≥33%. The particle size of the porous ceramic particles is 0.06-0.5 mm. The pore size distribution of the porous ceramic particles is ≥227 nm.

2. The porous ceramic-polymer composite material according to claim 1, characterized in that, When the polymer matrix is ​​rubber, the porous ceramic particles are modified porous ceramic particles, which are porous ceramic particles modified with nitrile rubber surface.

3. The porous ceramic-polymer composite material according to claim 1 or 2, characterized in that, The porosity of the porous ceramic particles is 33-63%.

4. The porous ceramic-polymer composite material according to claim 1 or 2, characterized in that, The porous ceramic particles have a particle size of 0.06~0.3mm.

5. The porous ceramic-polymer composite material according to claim 1 or 2, characterized in that, The porous ceramic particles have a pore size distribution of 220~6050nm.

6. The porous ceramic-polymer composite material according to claim 1, characterized in that, The method for preparing the porous ceramic particles includes the following steps: Ceramic aggregate, pore-forming agent, and binder are wet-mixed to obtain a mixture. The ceramic aggregate includes kaolin, feldspar, and quartz, with the mass ratio of kaolin to feldspar being 4:(3~9) and the mass ratio of kaolin to quartz being 4:(1~3). The pore-forming agent includes one or more of polyvinyl alcohol, polymethyl methacrylate, acrylate copolymers, and polystyrene, and the mass percentage of the pore-forming agent in the ceramic aggregate is 10~35%. The mixture is pressed into a molded shape to obtain a molded body; The molded body is dried, crushed, and sieved in sequence to obtain ceramic particles; The ceramic particles are sintered to obtain the porous ceramic material. The sintering includes the following steps: heating to a first temperature at a first heating rate and holding for a first time; then heating from the first temperature to a second temperature at a second heating rate and holding for a second time; wherein the first heating rate is ≤1℃ / min, the first temperature is 360~520℃, the first holding time is 30~120min, the second heating rate is 1~10℃ / min, the second temperature is 1140~1160℃, and the second holding time is 10~60min.

7. The porous ceramic-polymer composite material according to claim 6, characterized in that, The pore-forming agent is an acrylate copolymer, and the mass percentage of the pore-forming agent to the ceramic aggregate is 10-30%; the binder is polyvinyl alcohol, and the mass percentage of the binder to the ceramic aggregate is ≤8%.

8. The porous ceramic-polymer composite material according to claim 1, characterized in that, The porous ceramic-polymer composite material includes a first structural unit and a second structural unit. The first structural unit includes a first base layer and a plurality of sound-absorbing wedges disposed on the first base layer. The second structural unit includes a second base layer and a plurality of cavities equal in number to the sound-absorbing wedges are disposed on the second base layer, and one sound-absorbing wedge is inserted into any one of the cavities.

9. The method for preparing the porous ceramic-polymer composite material according to any one of claims 1 to 8, characterized in that, When the polymer matrix is ​​rubber, the following steps are included: mixing the porous ceramic particles and rubber in sequence and molding vulcanization to obtain the porous ceramic-polymer composite material; When the polymer matrix is ​​polyvinyl chloride, the process includes the following steps: mixing the polyvinyl chloride, plasticizer, stabilizer and porous ceramic particles to obtain a mixture; heating the mixture to obtain the porous ceramic-polymer composite material.

10. The application of the porous ceramic-polymer composite material according to any one of claims 1 to 8 or the porous ceramic-polymer composite material prepared by the preparation method according to claim 9 in sound-absorbing materials.

Images