Mesoporous ceramic / chlorinated polypropylene carbonate sound insulation microporous foam material and preparation method thereof

Abstract

The invention relates to the technical field of sound insulation and noise reduction foam, in particular to a mesoporous ceramic / chlorinated polypropylene carbonate sound insulation microporous foam material and a preparation method thereof, and the foam material is prepared from the following raw materials in parts by mass: 2-20 parts of mesoporous ceramic and 80-98 parts of chlorinated polypropylene carbonate. The mesoporous ceramic / chlorinated polypropylene carbonate foam material has the advantages of being high in strength, low in density, excellent in sound insulation performance, environmentally friendly and the like, the average transmission loss at the medium-high frequency of 1000-6300 Hz can reach 46-51 dB, the compression modulus can reach 38-48 MPa, the compression strength can reach 2.6-3.7 MPa, and the mesoporous ceramic / chlorinated polypropylene carbonate foam material is an excellent novel light sound insulation foam material and has good application prospects. The method can be applied to the fields of rail transit, recording studios, building walls and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of sound insulation and noise reduction foams, and particularly relates to a mesoporous ceramic / chlorinated polypropylene carbonate sound insulation microporous foam material and a preparation method thereof. Background Art

[0002] With the acceleration of the urbanization process, noise pollution has become a prominent problem threatening public health and the quality of life. The noise energy released in scenarios such as traffic engines, machining, and air conditioner exteriors is mostly concentrated in the 1000 - 6300 Hz mid - high frequency band. Such sound waves are not only easy to spread through building gaps but also form reverberation due to reflection superposition, leading to the deterioration of the indoor sound environment. Traditional sound insulation materials such as fiberglass boards or rock wool can absorb some high - frequency sound energy, but their fiber structures are prone to aging and powdering, and the transmission loss (TL) in the key frequency band of 1000 - 2000 Hz is insufficient (generally lower than 25 dB), making it difficult to meet the stringent requirements of scenarios such as precision laboratories and high - end office spaces. Sound insulation microporous foams have achieved a "thin - layer high - efficiency" noise reduction breakthrough through the precise regulation of micron - level pores: their microporous network forces sound waves to undergo viscous friction and heat conduction dissipation in tortuous channels, and have good noise reduction performance in the mid - high frequency band (1000 - 6300 Hz).

[0003] The current research and development of sound-insulating microcellular foams still faces two core challenges: one is the insufficient broadband uniform sound insulation performance in the medium and high frequency bands (such as 1000 - 4000 Hz). Due to the single pore distribution of existing materials, there is often a sudden drop in the transmission loss in specific frequency bands; the other is the structural stability defect in complex environments. For example, high temperature causes the polymer matrix to soften and pore collapse, or oil pollution invades the micropores, resulting in acoustic impedance mismatch. In response to these problems, in 2023, the academic and industrial circles proposed multi-dimensional solutions: The Fraunhofer Institute in Germany (Patent EP2023078567) developed a bionic "multi-layer heterogeneous pore size" foam. Through the vertical gradient arrangement of three levels of pores with diameters of 200μm, 500μm, and 800μm, the average transmission loss in the 2000 - 5000 Hz frequency band was increased to 42 dB, but the thickness reached 2.5 cm; in the ceramic composite sound-insulating material actually developed by Toray Industries, Inc. in Japan (Patent JP2021182234A published in 2021), the thickness of the silicon carbide-modified polyimide microcellular foam is 3 - 5 mm, and the transmission loss of the 2000 - 4000 Hz noise is stable at 28 - 32 dB (equivalent to blocking about 90% - 95% of the incident sound energy) in an environment of 100 - 120 °C, but there is still room for improvement in the sound insulation performance. In addition, the Tsinghua University team proposed the concept of "actively regulating micropores" (Patent CN202410123456.7). Through the coupling of piezoelectric materials and microporous structures, the opening and closing state of the pores is adjusted in real time to match the noise spectrum. Laboratory data shows that the instantaneous transmission loss of the 3000 Hz sudden noise can reach 50 dB, but it only targets specific frequencies. The present invention provides a mesoporous ceramic / chlorinated polypropylene carbonate sound-insulating microcellular foam material, which has excellent sound insulation performance in the medium and high frequencies (1000 - 6300 Hz), the transmission loss can reach 46 - 51 dB, the density is 0.51 - 0.65 g / cm 3 , the porosity is 48 - 63%, the compression modulus can reach 38 - 48 MPa, and the compression strength can reach 2.6 - 3.6 MPa. It is an excellent new type of lightweight sound-insulating foam material and can be applied to fields such as rail transit, recording studios, and building walls. Summary of the Invention

[0004] One of the purposes of the present invention is to provide a mesoporous ceramic / chlorinated polypropylene carbonate sound-insulating microcellular foam material, which has the advantages of low density, excellent sound insulation performance, and environmental protection.

[0005] Another purpose of the present invention is to provide a preparation method of a mesoporous ceramic / chlorinated polypropylene carbonate sound-insulating microcellular foam material. Through the physical confinement supercritical CO2 foaming technology, the cell size and sample size of the mesoporous ceramic / chlorinated polypropylene carbonate microcellular foam are precisely controlled, so as to have good noise reduction performance in the whole frequency band.

[0006] One of the solutions adopted by the present invention to achieve its purpose is: a mesoporous ceramic / chlorinated poly(propylene carbonate) sound-insulating microporous foam material, which is made from the following raw materials in parts by mass: 2-20 parts of mesoporous ceramic and 80-98 parts of chlorinated poly(propylene carbonate) (CPPC).

[0007] Preferably, the mesoporous ceramic is prepared by mixing sodium alkaline bentonite, asphalt with aqueous starch, silver citrate, and ferrous citrate aqueous solution, drying under air isolation conditions, and then calcining at 800-1200 °C for 7-8 h and cooling and grinding. The prepared mesoporous ceramic has a particle size of 100-1000 nm and a pore size of 20-30 nm.

[0008] The present invention effectively increases the contact area with the CPPC matrix by constructing a composite structure of hook-shaped iron nanoparticles and silver nanoparticles on the surface of the mesoporous ceramic. The mesoporous ceramic plays a dual role in the composite material: on the one hand, as a heterogeneous nucleating agent, it effectively refines the cell structure by promoting cell nucleation during the foaming process of the material, and extends the sound wave propagation path to enhance the acoustic performance; on the other hand, as a reinforcing phase, it significantly improves the mechanical properties of the foam material. This dual optimization design of structure-function enables the material to have excellent sound insulation performance and mechanical strength at the same time.

[0009] Preferably, the chlorinated poly(propylene carbonate) is prepared by modifying poly(propylene carbonate) through aqueous phase suspension chlorination reaction.

[0010] One of the solutions adopted by the present invention to achieve its second purpose is: a preparation method of the above-mentioned mesoporous ceramic / chlorinated poly(propylene carbonate) sound-insulating microporous foam material, and the mesoporous ceramic / chlorinated poly(propylene carbonate) sound-insulating microporous foam material is prepared from mesoporous ceramic and chlorinated poly(propylene carbonate) by using physical confinement supercritical fluid foaming technology.

[0011] Preferably, it includes the following steps:

[0012] (1) Mix the raw materials evenly according to the required parts by mass to obtain a mixed raw material;

[0013] (2) Melt-blend the mixed raw material in step (1) to obtain a chlorinated poly(propylene carbonate) based composite material;

[0014] (3) Hot-press the chlorinated poly(propylene carbonate) based composite material after melt-blending in step (2) to prepare a chlorinated poly(propylene carbonate) based composite material sheet;

[0015] (4) Supercritically foam the composite material sheet with supercritical CO2 by controlling the foaming temperature, foaming pressure, and physical confinement size to obtain a mesoporous ceramic / chlorinated poly(propylene carbonate) microporous foam material.

[0016] Preferably, in step (1), when mixing, the rotation speed is 1500-2500 r / min.

[0017] Preferably, in step (2), during melt blending, the rotation speed is 50 - 70 r / min and the temperature is 120 - 140 °C.

[0018] Preferably, in step (3), the hot pressing conditions are a hot pressing temperature of 120 - 140 °C, a pressure of 12 - 16 MPa, a holding pressure time of 5 - 15 min, and the thickness of the poly(propylene carbonate chloride) - based composite sheet is 2 - 5 mm.

[0019] Preferably, in step (4), the foaming conditions are a foaming temperature of 32 - 60 °C, a foaming pressure of 12 - 16 MPa, a saturation time of 18 - 24 h, and a foaming time of 10 - 20 s.

[0020] Preferably, in step (4), physical confinement causes the material after foaming of the composite sheet to thicken by 1.5 - 2 times, and the average pore diameter of the pores is 5 - 7 μm.

[0021] The present invention has the following advantages and beneficial effects:

[0022] The sound - insulating composite material of the present invention achieves efficient noise reduction through the synergistic effect of a multi - scale pore structure. Its core structure consists of three elements: (1) a composite pore system composed of micron - sized closed pores of the CPPC matrix and nano - sized open pores of mesoporous ceramics; (2) mesoporous ceramics with nano - sized pore characteristics; (3) the CPPC (poly(propylene carbonate chloride)) matrix as the continuous phase. This structure achieves noise reduction through a dual sound energy dissipation mechanism: First, the composite pore system, through the synergistic effect of micron - sized closed pores and nano - sized open pores, promotes multiple reflections, refractions, and turbulent effects of the incident sound wave at the pore interface, achieving primary energy attenuation; Second, the mesoporous ceramics combined with the CPPC matrix interface utilize their nano - sized porous structure to secondarily absorb the residual sound wave penetrating the matrix, and further weaken the sound energy through sound wave interference and viscous dissipation effects within the nano - sized pore channels. This spatial coupling effect of the micro - nano multi - level pore structure enables the material to exhibit excellent sound - insulating performance in a wide frequency band.

[0023] The mesoporous ceramic / poly(propylene carbonate chloride) foam material of the present invention has the advantages of high strength, low density, excellent sound - insulating performance, environmental protection, etc. The average transmission loss in the medium - high frequency range of 1000 - 6300 Hz can reach 46 - 51 dB, the compression modulus can reach 38 - 48 MPa, and the compression strength can reach 2.6 - 3.7 MPa. It is an excellent new lightweight sound - insulating foam material and can be applied to fields such as rail transit, recording studios, and building walls.

[0024] The preparation method of the present invention, through the physical confinement supercritical CO2 foaming technology, precisely controls the pore size of the mesoporous ceramic / poly(propylene carbonate chloride) microcellular foam and the sample size, thereby having good noise reduction performance in the entire frequency band. Description of the Drawings

[0025] Figure 1 This is the microscopic morphology diagram of the mesoporous ceramic of the present invention;

[0026] Figure 2 This is the microscopic morphology diagram of the mesoporous ceramic / chlorinated poly(propylene carbonate) sound insulation foam of the present invention. Detailed implementation manners

[0027] To better understand the present invention, the following examples are further descriptions of the present invention, but the content of the present invention is not limited to the following examples only.

[0028] In the present invention, the chlorinated poly(propylene carbonate) is provided by the Changchun Institute of Applied Chemistry, Chinese Academy of Sciences (China Patent ZL201410155108.8), and the mesoporous ceramic is provided by Wuhan Maifeite Technology Co., Ltd.

[0029] The mesoporous ceramic is prepared by mixing sodium alkaline bentonite (1000 mesh), asphalt (1000 mesh) with water-soluble starch (1000 mesh), silver citrate, and an aqueous solution of ferrous citrate, drying under air isolation conditions, and then calcining at 800 - 1200 °C for 7 - 8 h and then cooling and grinding.

[0030] As Figure 1 The microscopic morphology characterization results of the shown mesoporous ceramic show that the material has mesopores of about 25 nm. It should be noted that there are a large number of hook-shaped anchoring structures of 5 - 10 nm on its surface and in the pore channels. This special morphology is composed of the composite of zero-valent iron nanoparticles and silver nanoparticles. By increasing the contact interface area between the material and the matrix, increasing the acoustic wave propagation path, and improving the cell structure, the introduction of this composite structure significantly improves the acoustic noise reduction performance of the mesoporous ceramic / CPPC foam.

[0031] Example 1

[0032] (1) Place the chlorinated poly(propylene carbonate) in an oven at 40 °C and dry for 5 h, then take it out. Weigh 5 parts of the mesoporous ceramic and 96 parts of the chlorinated poly(propylene carbonate), and mix them evenly in a mixer at a rotation speed of 1500 r / min for 30 s.

[0033] (2) Pour the mixture into a torque rheometer and melt-blend at a temperature of 120 °C and a rotation speed of 50 r / min for 12 min to obtain a CPPC-based composite material.

[0034] (3) Press the CPPC-based composite material at a temperature of 120 °C, a pressure of 16 MPa, and a pressure holding time of 15 min to obtain a CPPC-based composite material sheet with a thickness of 2 mm.

[0035] (4) Place the CPPC-based composite material sheet in a high-pressure reactor with a physical confinement thickness of 4 mm, introduce CO2 gas at 12 MPa, and then saturate it at 60 °C for 20 h.

[0036] (5) Remove the oil bath heating device, quickly release the pressure. A large amount of gas overflows from the mesoporous ceramic / CPPC composite material and forms uniform pores. The foaming time is 15 s. Then place the high-temperature reactor in an ice-water mixture and cool it to room temperature to obtain the mesoporous ceramic / CPPC microcellular foam material. Perform performance tests on the mesoporous ceramic / CPPC microcellular foam material prepared in this example.

[0037] The density of the prepared mesoporous ceramic / CPPC microcellular foam material is 0.54 g / cm 3 , the porosity is 55%, the average pore diameter of the pores is 6.5 μm, the compression modulus is 40 MPa, the compression strength is 2.9 MPa, and the average transmission loss at 1000 - 6300 Hz is 46 dB. Its microscopic morphology diagram is as shown in Figure 2 (d). The pore structure is elliptical closed pores, with a relatively regular shape. The pore diameter decreases, and the pore wall decreases slightly. Both the sound insulation performance and mechanical properties are improved.

[0038] Example 2

[0039] (1) Place the poly(propylene carbonate) chloride in an oven at 40 °C and dry it for 5 h, then take it out. Weigh 2 parts of mesoporous ceramic and 98 parts of poly(propylene carbonate) chloride, and mix them evenly in a mixer at a rotation speed of 2000 r / min for 40 s.

[0040] (2) Pour the mixture into a torque rheometer and melt-blend it at a temperature of 130 °C and a rotation speed of 60 r / min for 12 min to obtain the CPPC-based composite material.

[0041] (3) Press the CPPC-based composite material at a temperature of 130 °C, a pressure of 16 MPa, and a holding pressure of 15 min to obtain a CPPC-based composite material sheet with a thickness of 5 mm.

[0042] (4) Place the CPPC-based composite material sheet in a high-pressure reactor with a physical confinement thickness of 8 mm, introduce CO2 gas at 14 MPa, and then saturate it at 50 °C for 22 h.

[0043] (5) Remove the oil bath heating device, quickly release the pressure. A large amount of gas overflows from the mesoporous ceramic / CPPC composite material and forms uniform pores. The foaming time is 20 s. Then place the high-temperature reactor in an ice-water mixture and cool it to room temperature to obtain the mesoporous ceramic / CPPC microcellular foam material. Perform performance tests on the mesoporous ceramic / CPPC microcellular foam material prepared in this example.

[0044] The mesoporous ceramic / CPPC microcellular foam materials prepared in this example were subjected to performance tests.

[0045] The density of the prepared mesoporous ceramic / CPPC microcellular foam material is 0.51 g / cm 3 , the porosity is 48%, the average pore diameter of the pores is 5.6 μm, the compression modulus is 38 MPa, the compression strength is 2.6 MPa, the average transmission loss at 1000 - 6300 Hz is 46 dB, and its microscopic morphology is as shown in Figure 2 (e) in the figure. The pore structure is circular closed pores, with a relatively regular shape. The pore diameter decreases, and both the sound insulation performance and mechanical properties are improved.

[0046] Example 3

[0047] (1) Poly(propylene carbonate) chloride was placed in an oven at 40 °C and dried for 5 h, then taken out. 16 parts of mesoporous ceramic and 84 parts of poly(propylene carbonate) chloride were weighed and mixed evenly in a mixer at a rotation speed of 2000 r / min for 40 s.

[0048] (2) The mixture was poured into a torque rheometer and melt-blended at a temperature of 130 °C and a rotation speed of 60 r / min for 12 min to obtain a CPPC-based composite material.

[0049] (3) The CPPC-based composite material was hot-pressed at a temperature of 130 °C, a pressure of 14 MPa, and a pressure holding time of 10 min to obtain a CPPC-based composite material sheet with a thickness of 4 mm.

[0050] (4) The CPPC-based composite material sheet was placed in a high-pressure autoclave with a physical confinement thickness of 7 mm, and 14 MPa of CO2 gas was introduced, and then saturated at 50 °C for 24 h.

[0051] (5) The oil bath heating device was removed, and the pressure was rapidly released. A large amount of gas overflowed from the mesoporous ceramic / CPPC composite material and formed uniform pores. The foaming time was 12 s. Then the high-temperature autoclave was placed in an ice-water mixture and cooled to room temperature to obtain the mesoporous ceramic / CPPC microcellular foam material. The mesoporous ceramic / CPPC microcellular foam materials prepared in this example were subjected to performance tests.

[0052] The density of the prepared mesoporous ceramic / CPPC microcellular foam material is 0.57 g / cm 3 , the porosity is 63%, the average pore diameter of the pores is 5.9 μm, the compression modulus is 43 MPa, the compression strength is 3.3 MPa, the average transmission loss at 1000 - 6300 Hz is 51 dB, and its microscopic morphology is as shown in Figure 2 (f) in the figure. The pore structure has elliptical and circular shapes. The pore diameter decreases, and the pore wall becomes thinner. Both the sound insulation performance and mechanical properties are greatly improved.

[0053] Example 4

[0054] (1) Place the chlorinated polypropylene carbonate in an oven at 40 °C and dry it for 5 h, then take it out. Weigh 20 parts of mesoporous ceramics and 80 parts of chlorinated polypropylene carbonate, and mix them evenly in a mixer at a rotation speed of 2500 r / min for 60 s.

[0055] (2) Pour the mixture into a torque rheometer and melt-blend it at a temperature of 140 °C and a rotation speed of 70 r / min for 12 min to obtain a CPPC-based composite material.

[0056] (3) Press the CPPC-based composite material at a temperature of 140 °C, a pressure of 14 MPa, and a holding pressure of 10 min to obtain a CPPC-based composite material sheet with a thickness of 3 mm.

[0057] (4) Place the CPPC-based composite material sheet in a high-pressure reactor with a physical confinement thickness of 5 mm, introduce CO2 gas at 16 MPa, and then saturate it at 40 °C for 18 h.

[0058] (5) Remove the heating device of the oil bath, quickly release the pressure, and a large amount of gas overflows from the mesoporous ceramics / CPPC composite material and forms uniform foam cells. The foaming time is 17 s. Then place the high-temperature reactor in an ice-water mixture and cool it to room temperature to obtain the mesoporous ceramics / CPPC microcellular foam material. Perform performance tests on the mesoporous ceramics / CPPC microcellular foam material prepared in this example.

[0059] The density of the prepared mesoporous ceramics / CPPC microcellular foam material is 0.65 g / cm 3 , the porosity is 51%, the average pore diameter of the foam cells is 6.0 μm, the compression modulus is 48 MPa, the compression strength is 3.7 MPa, the average transmission loss at 1000 - 6300 Hz is 48 dB, and its micrograph is as shown in Figure 2 (g), the pore structure is circular, the shape is regular, the pore diameter decreases, the pore wall becomes thinner, and both the sound insulation performance and the mechanical performance are greatly improved.

[0060] Example 5

[0061] (1) Place the chlorinated polypropylene carbonate in an oven at 40 °C and dry it for 5 h, then take it out. Weigh 8 parts of mesoporous ceramics and 92 parts of chlorinated polypropylene carbonate, and mix them evenly in a mixer at a rotation speed of 2500 r / min for 60 s.

[0062] (2) Pour the mixture into a torque rheometer and melt-blend it at a temperature of 140 °C and a rotation speed of 70 r / min for 12 min to obtain a CPPC-based composite material.

[0063] (3) The CPPC-based composite material is hot-pressed into a CPPC-based composite material sheet at a temperature of 140 °C, a pressure of 12 MPa, a pressure holding time of 5 min, and a hot pressing thickness of 5 mm.

[0064] (4) The CPPC-based composite material sheet is placed in a high-pressure reactor with a physical confinement thickness of 8 mm, and CO2 gas at 16 MPa is introduced, and then saturated at 32 °C for 20 h.

[0065] (5) Remove the oil bath heating device, quickly release the pressure. A large amount of gas overflows from the mesoporous ceramic / CPPC composite material and forms uniform pores, and the foaming time is 13 s. Then, the high-temperature reactor is placed in an ice-water mixture and cooled to room temperature to obtain the mesoporous ceramic / CPPC microcellular foam material. The performance of the mesoporous ceramic / CPPC microcellular foam material prepared in this example is tested.

[0066] The density of the prepared mesoporous ceramic / CPPC microcellular foam material is 0.61 g / cm 3 , the porosity is 59%, the average pore diameter of the pores is 5.8 μm, the compression modulus is 44 MPa, the compression strength is 3.4 MPa, the average transmission loss at 1000 - 6300 Hz is 49 dB, and its microscopic morphology is shown in Figure 2 as shown in (h) in it. The pore structure is circular, with regular shape, decreasing pore diameter, uniform distribution, and significant improvements in sound insulation performance and mechanical properties.

[0067] Comparative Example 1

[0068] (1) The chlorinated polypropylene carbonate is taken out after being dried in an oven at 40 °C for 5 h. Weigh 100 parts of chlorinated polypropylene carbonate and mix it evenly in a mixer at a rotation speed of 1500 r / min for 30 s.

[0069] (2) Pour the mixture into a torque rheometer and melt-blend it at a temperature of 120 °C and a rotation speed of 50 r / min for 12 min to obtain a CPPC-based composite material.

[0070] (3) The CPPC-based composite material is hot-pressed into a CPPC-based composite material sheet at a temperature of 120 °C, a pressure of 12 MPa, a pressure holding time of 5 min, and a hot pressing thickness of 5 mm.

[0071] (4) The CPPC-based composite material sheet is placed in a high-pressure reactor with a physical confinement thickness of 7 mm, and CO2 gas at 12 MPa is introduced, and then saturated at 60 °C for 18 h.

[0072] (5) Remove the oil bath heating device, quickly release the pressure, a large amount of gas overflows in the CPPC and homogeneous pores are formed, with a foaming time of 10 s. Then place the high-temperature reaction kettle in an ice-water mixture and cool it to room temperature to obtain the CPPC microcellular foam material. The density of the CPPC microcellular foam material prepared in the comparative example is 0.49 g / cm 3 , the porosity is 45%, the average pore diameter of the pores is 7.2 μm, the compression modulus is 32 MPa, the compression strength is 2.1 MPa, the transmission loss at 1000 - 6300 Hz is 31 dB, and its microscopic morphology is as shown in Figure 2 (a) in, the pore diameter is relatively large, most of the pore structures are elliptical closed pores, the pore walls are relatively thick, and the pore distribution is relatively uniform.

[0073] Comparative Example 2

[0074] (6) Place the poly(propylene carbonate) chloride in an oven at 40 °C and dry it for 5 h, then take it out, weigh 10 parts of mesoporous ceramics, 90 parts of poly(propylene carbonate) chloride, and mix them evenly in a mixer at a rotation speed of 1800 r / min for 40 s.

[0075] (7) Pour the mixture into a torque rheometer and melt-blend it at a temperature of 130 °C and a rotation speed of 50 r / min for 12 min to obtain the CPPC-based composite material.

[0076] (8) Press the CPPC-based composite material at a temperature of 130 °C, a pressure of 13 MPa, and a holding pressure of 10 min to obtain a CPPC-based composite material sheet with a thickness of 2 mm.

[0077] (9) Place the CPPC-based composite material sheet in a high-pressure reaction kettle with a physical confinement thickness of 5 mm, introduce CO2 gas at 12 MPa, and then saturate it at 50 °C for 20 h.

[0078] (10) Remove the oil bath heating device, quickly release the pressure, a large amount of gas overflows in the mesoporous ceramic / CPPC composite material and uniform pores are formed, with a foaming time of 18 s. Then place the high-temperature reaction kettle in an ice-water mixture and cool it to room temperature to obtain the mesoporous ceramic / CPPC microcellular foam material. Perform performance tests on the mesoporous ceramic / CPPC microcellular foam material prepared in this example.

[0079] The density of the prepared mesoporous ceramic / CPPC microcellular foam material is 0.42 g / cm 3 , the porosity is 46%, the average pore diameter of the pores is 7.5 μm, the compression modulus is 23 MPa, the compression strength is 1.5 MPa, the average transmission loss at 1000 - 6300 Hz is 32 dB, and its microscopic morphology is as shown in Figure 2 (b) in, the pore structure is circular closed pores, the pore diameter is relatively large, and both the sound insulation performance and the mechanical properties are average.

[0080] Comparative Example 3

[0081] (11) The chlorinated polypropylene carbonate was placed in an oven at 40 °C and dried for 5 h, then taken out. 13 parts of mesoporous ceramics and 87 parts of chlorinated polypropylene carbonate were weighed and mixed evenly in a mixer at a rotation speed of 2500 r / min for 60 s.

[0082] (12) The mixture was poured into a torque rheometer and melt-blended at a temperature of 120 °C and a rotation speed of 60 r / min for 12 min to obtain a CPPC-based composite material.

[0083] (13) The CPPC-based composite material was hot-pressed into a CPPC-based composite material sheet at a temperature of 120 °C, a pressure of 15 MPa, and a pressure holding time of 8 min, with a thickness of 5 mm.

[0084] (14) The CPPC-based composite material sheet was placed in a high-pressure reactor with a physical confinement thickness of 6 mm, and CO2 gas at 12 MPa was introduced, and then saturated at 40 °C for 22 h.

[0085] (15) The oil bath heating device was removed, and the pressure was rapidly released. A large amount of gas overflowed from the mesoporous ceramic / CPPC composite material and formed uniform pores, and the foaming time was 10 s. Then the high-temperature reactor was placed in an ice-water mixture and cooled to room temperature to obtain the mesoporous ceramic / CPPC microcellular foam material. The performance of the mesoporous ceramic / CPPC microcellular foam material prepared in this example was tested.

[0086] The density of the prepared mesoporous ceramic / CPPC microcellular foam material is 0.57 g / cm 3 , the porosity is 45%, the average pore diameter of the pores is 6.1 μm, the compression modulus is 36 MPa, the compression strength is 2.7 MPa, the average transmission loss at 1000 - 6300 Hz is 34 dB, and its microscopic morphology diagram is as shown in Figure 2 (c), the pore structure is elliptical closed pores, the pore size distribution is relatively wide, there are many large pores and small pores, and the sound insulation performance and mechanical properties are average.

[0087] Table 1 Performance parameter table of sound insulation microcellular foams prepared in Comparative Examples 1 - 3 and Examples 1 - 5

[0088]

[0089]

[0090] Table 2 Transmission loss performance parameter table of sound insulation microcellular foams prepared in Comparative Examples 1 - 3 and Examples 1 - 5

[0091]

[0092] Based on the data analysis of Comparative Examples 1-3 and Examples 1-5 in Table 1, it can be seen that the mesoporous ceramic / chlorinated polypropylene carbonate sound-insulating microporous foam material developed by the present invention exhibits significant comprehensive performance advantages. The density is in the range of 0.51-0.65 g / cm 3 ; in terms of acoustic performance in the medium and high frequency bands (1000-6300 Hz), the average sound wave transmission loss value is increased to the range of 46-51 dB. Compared with CPPC foam, an acoustic performance optimization of 48%-65% is achieved; in terms of mechanical properties, the compression modulus reaches 38-48 MPa, with an increase of 19%-50% compared to CPPC foam, and the compression strength index is increased to 2.6-3.7 MPa, with an increase of 24%-76%. This multi-scale structure design enables the material to successfully achieve the synergistic improvement of acoustic protection performance and mechanical load-bearing capacity while maintaining its lightweight characteristics.

[0093] The above is the preferred implementation manner of the present invention. Of course, the scope of the rights of the present invention cannot be limited thereby. It should be pointed out that for those of ordinary skill in the art in this technical field, without departing from the principle of the present invention, several improvements and changes can still be made, and these improvements and changes are also regarded as the protection scope of the present invention.

Claims

1. A mesoporous ceramic / chlorinated polypropylene carbonate sound insulation microporous foam material, characterized in that: The invention is prepared from the following raw materials in parts by weight: 2-20 parts of mesoporous ceramics and 80-98 parts of chlorinated polypropylene carbonate.

2. The mesoporous ceramic / chlorinated polypropylene carbonate sound insulation microporous foam material according to claim 1, characterized in that: The mesoporous ceramic is prepared by mixing alkaline sodium bentonite, asphalt with water-soluble starch, silver citrate and ferrous citrate aqueous solution, drying under air-tight conditions, calcining at 800-1200° C. for 7-8 hours, and then cooling and grinding. The prepared mesoporous ceramic has a particle size of 100-1000 nm and a pore size of 20-30 nm.

3. The mesoporous ceramic / chlorinated polypropylene carbonate sound insulation microporous foam material according to claim 1, characterized in that: The chlorinated polypropylene carbonate is prepared by modifying polypropylene carbonate through a water phase suspension chlorination reaction.

4. A method for preparing a mesoporous ceramic / chlorinated polypropylene carbonate sound insulation microporous foam material according to any one of claims 1 to 3, characterized in that: The mesoporous ceramic / chlorinated polypropylene carbonate sound insulation microporous foam material is prepared from mesoporous ceramic and chlorinated polypropylene carbonate by adopting physical restraint supercritical fluid foaming technology.

5. The method for preparing the mesoporous ceramic / chlorinated polypropylene carbonate sound insulation microporous foam material according to claim 4, characterized in that: The following steps are involved: (1) uniformly mixing the raw materials according to the required mass fractions to obtain a mixed raw material; (2) melt-blending the mixed raw materials in step (1) to obtain a chlorinated polypropylene carbonate-based composite material; (3) hot pressing the chlorinated polypropylene carbonate-based composite material after melt blending in step (2) to prepare a chlorinated polypropylene carbonate-based composite material sheet; (4) The composite material sheet is subjected to supercritical CO2 foaming by controlling the foaming temperature, foaming pressure and physical constraint size to obtain a mesoporous ceramic / chlorinated polypropylene carbonate microporous foam material.

6. The method for preparing the mesoporous ceramic / chlorinated polypropylene carbonate sound insulation microporous foam material according to claim 5, characterized in that: In step (1), during mixing, the rotation speed is 1500-2500 r / min.

7. The method for preparing the mesoporous ceramic / chlorinated polypropylene carbonate sound insulation microporous foam material according to claim 5, characterized in that: In step (2), during melt blending, the rotation speed is 50-70 r / min and the temperature is 120-140°C.

8. The method for preparing the mesoporous ceramic / chlorinated polypropylene carbonate sound insulation microporous foam material according to claim 5, characterized in that: In step (3), the hot pressing conditions are as follows: a hot pressing temperature of 120-140° C., a pressure of 12-16 MPa, a holding time of 5-15 min, and a thickness of the chlorinated polypropylene carbonate-based composite material sheet of 2-5 mm.

9. The method for preparing the mesoporous ceramic / chlorinated polypropylene carbonate sound insulation microporous foam material according to claim 5, characterized in that: In step (4), the foaming conditions are as follows: foaming temperature 32-60° C., foaming pressure 12-16 MPa, saturation time 18-24 h, and foaming time 10-20 s.

10. The method for preparing the mesoporous ceramic / chlorinated polypropylene carbonate sound insulation microporous foam material according to claim 5, characterized in that: In step (4), physical restraint causes the thickness of the composite material sheet to increase by 1.5 to 2 times after foaming.

Images