Flame-retardant nuclear radiation protection sound-absorbing composite board and preparation method thereof

Abstract

The present application relates to the technical field of functional textiles, and particularly relates to a flame-retardant nuclear radiation protection sound-absorbing composite board and a preparation method thereof, which comprises a flame-retardant layer, a first sound-absorbing layer, a nuclear radiation protection layer and a second sound-absorbing layer, wherein the nuclear radiation protection layer is a gadolinium oxide nanofiber membrane prepared by using electrospinning technology with gadolinium acetate and polyvinyl alcohol as precursors; the flame-retardant nuclear radiation protection function is combined with the sound-absorbing board; the surface-modified gadolinium oxide fiber with high shielding performance for neutrons and gamma rays prepared by using electrospinning technology and the flame-retardant polyester fiber are added to make the sound-absorbing board achieve good nuclear radiation protection, flame-retardant effect and sound-absorbing effect at the same time, realize the integration of nuclear radiation protection, flame retardation and sound absorption, have multifunctionality, and have low preparation cost, green environmental protection, light weight and durability.

Description

Technical Field

[0001] This invention relates to the field of functional textile technology, and in particular to a flame-retardant nuclear radiation protection sound-absorbing composite board and its preparation method. Background Technology

[0002] As scientific research into the hazards of noise pollution deepens, people have gradually recognized its severity, leading to increased research into sound insulation and noise reduction measures. The most effective noise control method in practical applications is through the use of sound-absorbing materials. Sound-absorbing panels are ideal sound-absorbing and noise-reducing materials, widely used in schools, theaters, stadiums, and other public gathering places, as well as in car interiors, transportation tracks, hospitals, and military equipment. Simultaneously, higher and more demanding requirements have been placed on the performance of sound-absorbing materials. With the continuous development and application of nuclear technology in my country, and the increasing demand for flame-retardant materials from various sectors of society, the need for sound-absorbing materials with special properties has become more urgent. Sound-absorbing materials must evolve from a single sound-absorbing function to a multi-functional approach encompassing high efficiency, flame retardancy, moisture resistance, and nuclear radiation protection, providing people with a safer and more comfortable environment.

[0003] The working principle of sound-absorbing panels is that they have many small pores inside and on their surface. Sound energy is lost and its intensity attenuated during this process, resulting in sound absorption. Currently, sound-absorbing panels are mainly classified into the following categories: ① Mineral wool sound-absorbing panels (a new type of building sound insulation and decorative material made primarily of mineral wool, mixed with various appropriate additives in a certain proportion, and processed through specific procedures); ② Wood fiber sound-absorbing panels (made from wood fiber, mixed with various appropriate additives in a certain proportion, and produced through heating and pressurization); ③ Polyester fiber sound-absorbing panels (made from polyester fiber under hot-pressing conditions, and sound-absorbing panels of different densities can be produced by appropriately changing the processing conditions).

[0004] Sound-absorbing panels are used in various industries where many flammable and combustible materials are present, such as automotive interiors, nuclear plant facilities, and public gathering places, posing significant safety hazards. Therefore, flame-retardant fibers are becoming increasingly important for sound-absorbing panel applications. Combining sound-absorbing panels with flame-retardant fibers can slow the spread of flames, providing more escape time. Currently, commonly used flame-retardant fibers include flame-retardant fibers and fibers that have undergone flame-retardant finishing processes to achieve flame-retardant properties. Flame-retardant fibers are more expensive, while flame-retardant finishing processes are simple and can meet different levels of flame-retardant requirements, making it a widely used flame-retardant method.

[0005] CN104032845A discloses a flame-retardant sound-absorbing board, the preparation method of which includes: arranging a flame-retardant part, a material connecting part, a sound-absorbing part, and the material connecting part in sequence from top to bottom; molding under conditions of 160℃-195℃ and 1MPa-3MPa, causing the material connecting part to melt and connecting the flame-retardant part and the sound-absorbing part together to form a straw flame-retardant sound-absorbing board; wherein, the flame-retardant part includes flame-retardant fibers, the material connecting part includes chemical fibers; and the sound-absorbing part is made from raw materials including straw, waste fabrics, and hot-melt fibers. The product obtained by this invention not only has a high-efficiency sound absorption effect but also achieves flame retardancy, and the raw material selection and manufacturing cost are low, the process route is simple and environmentally friendly, bringing a breakthrough to the field of sound-absorbing materials.

[0006] Neutron shielding materials are a crucial component of radiation protection in many nuclear facilities. Various shielding materials are used to attenuate or absorb neutrons, such as concrete, polyethylene, heavy metals, boron, and boron-containing compounds (e.g., boron carbide, boron nitride, boron oxide). However, these materials have drawbacks that limit their application. Existing neutron and gamma-ray composite shielding materials, such as lead-boron polyethylene (PbPE), possess excellent overall shielding performance, are lightweight, small in size, and have a simplified shielding structure, leading to their widespread use in the shielding field. However, Pb's biological toxicity and environmental unfriendliness limit its application to some extent. Gadolinium (Gd), a rare earth element, possesses gamma-ray shielding capabilities as a high-z element. Its isotopes 155Gd and 157Gd also exhibit extremely high thermal neutron absorption cross-sections. Due to its thermal neutron absorption and gamma-ray shielding capabilities, it is widely used in shielding applications. In nature, it typically exists as gadolinium oxide (Gd2O3). Gd2O3 has excellent thermal stability, low toxicity, and is pollution-free, making it an excellent lead-free alternative material. Lead-free composite shielding materials have been successfully prepared using it, providing protection against nuclear radiation.

[0007] Existing technologies consist of single sound-absorbing panels or flame-retardant sound-absorbing panels, which cannot fully utilize the multi-functional characteristics of sound-absorbing panels. They do not integrate multiple functions such as flame retardancy, moisture resistance, antibacterial properties, and nuclear radiation protection, and cannot meet the needs of specific and special environments. For example, flame-retardant nuclear radiation protection sound-absorbing automotive interior materials that address the fire hazard of lithium batteries in new energy vehicles, and flame-retardant nuclear radiation protection sound-absorbing panels used in hospitals, nuclear reactors, nuclear power plants, nuclear fuel regeneration and processing plants, etc. Summary of the Invention

[0008] To address the shortcomings of existing technologies, a flame-retardant nuclear radiation protection sound-absorbing composite board and its preparation method are provided. This method combines flame retardancy and nuclear radiation protection functions with a sound-absorbing board. By incorporating surface-modified gadolinium oxide fibers with high shielding performance against neutrons and gamma rays, produced using electrospinning technology, and polyester fibers that have undergone flame-retardant finishing, the sound-absorbing board achieves good nuclear radiation protection and flame retardancy effects while absorbing sound and reducing noise. This integrates nuclear radiation protection, flame retardancy, and sound absorption, making it multifunctional, low-cost, environmentally friendly, lightweight, and durable.

[0009] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is a flame-retardant nuclear radiation protection sound-absorbing composite board, comprising a flame-retardant layer, a first sound-absorbing layer, a nuclear radiation protection layer, and a second sound-absorbing layer. The nuclear radiation protection layer is a gadolinium oxide nanofiber membrane prepared by electrospinning technology using gadolinium acetate and polyvinyl alcohol as precursors.

[0010] The flame-retardant nuclear radiation protection sound-absorbing composite board described above, wherein the flame-retardant layer, the first sound-absorbing layer, the nuclear radiation protection layer, the second sound-absorbing layer and the nuclear radiation protection layer are arranged sequentially from top to bottom. The first and second sound-absorbing layers are made of hemp fiber and low-melting-point polyester fiber, and the layers are tightly connected by thermal bonding of low-melting-point polyester fiber as the connecting part.

[0011] The aforementioned flame-retardant nuclear radiation protection sound-absorbing composite material uses gadolinium oxide nanofiber membranes prepared by electrospinning and thermal oxidation of polymer PVP, metal salt Gd(CH3COO)3 as precursor, and anhydrous ethanol as solvent.

[0012] The aforementioned flame-retardant nuclear radiation protection sound-absorbing composite board has a combustion growth rate index of 23 W / s, a longitudinal heat release of 2.5 MJ within 600s, a flame tip height of less than or equal to 150mm within 60s, and no internal combustion drippings igniting within 60s.

[0013] The aforementioned flame-retardant nuclear radiation protection sound-absorbing composite material has an average sound absorption coefficient exceeding 0.3, achieving a noise reduction of 4-7 dB, with the highest sound absorption coefficient reaching over 0.6 within the 125-400 Hz noise range.

[0014] The aforementioned flame-retardant nuclear radiation protection sound-absorbing composite material has the following nuclear radiation protection effect: neutron protection coefficient (Kn) close to 7 and gamma ray protection coefficient (Kr) greater than 9.

[0015] The preparation method of the above-mentioned flame-retardant nuclear radiation protection sound-absorbing composite material includes the following steps:

[0016] (1) Preparation of flame retardant layer: After the polyester fiber is combed, laid into a web, hot melt bonded, hot rolled into shape, it is treated with phosphorus flame retardant, dipped and rolled twice, dried, baked, washed with water and dried to obtain polyester fiber web.

[0017] (2) Preparation of gadolinium oxide fibers:

[0018] Step 1: Preparation of spinning solution. Polymer PVP and metal salt Gd(CH3COO)3 are used as raw materials, and anhydrous ethanol is used as solvent. First, a certain amount of PVP is dissolved in anhydrous ethanol, sealed and magnetically stirred for 10 minutes. After complete and uniform dissolution, Gd(CH3COO)3 powder is added, so that the mass fraction of polymer PVP is 6-8% and the mass fraction of Gd(CH3COO)3 is 9-12%. Magnetic stirring is continued for 11-12 hours until a completely transparent and clear solution is obtained, thus preparing the spinning precursor solution.

[0019] Step 2: Electrospinning is performed. The precursor solution is injected into the syringe. Under the action of the injection pump, the precursor solution forms droplets at the capillary opening. The receiving distance is adjusted, and the voltage distribution during the spinning process is controlled between 5 and 30 kV. The ambient temperature is 20°C and the humidity is within the range of 10% to 20%. The charged precursor solution sprayed from the nozzle forms fibers under the action of the electric field and precipitates on the aluminum foil receiving device. Finally, PVP / Gd(CH3COO)3 composite nanofibers are collected.

[0020] Step 3: The PVP / Gd(CH3COO)3 composite fibers obtained in the above process are subjected to thermal oxidation treatment. The collected fibers are placed in a vacuum drying oven and dried for 11-12 hours. They are then taken out and placed in a medium-temperature tube furnace or muffle furnace for thermal oxidation treatment at a certain heating rate. Pre-oxidation treatment is carried out at 200-300℃, followed by oxidation at 600-800℃ for 3-4 hours to finally obtain Gd2O3 nanofiber membrane.

[0021] (3) Preparation of sound-absorbing panels:

[0022] A multilayer gadolinium oxide nanofiber membrane is laminated with a polyester fiber web and heated to a temperature higher than the melting point of the low-melting-point polyester fiber to melt it into an adhesive. The adhesive is then molded at 170℃ and 2-3 MPa, melted, and shaped to ensure a tight bond between the layers, forming a flame-retardant, nuclear radiation-protective, and sound-absorbing composite board.

[0023] In the preparation method of the above-mentioned flame-retardant nuclear radiation protection sound-absorbing composite board, in step (1), the rolling liquid rate is 80%, and the first-dip and first-rolling impregnation liquid is composed of the following components: flame retardant FRC-1: 100~150g / L, disodium hydrogen phosphate: 7~10g / L, softener: 10-30g / L, penetrant JFC: 1~2g / L, the impregnation liquid is adjusted to pH 6.5, and the second-dip and second-rolling impregnation liquid is composed of the following components: flame retardant FRC-1: 100~150g / L, disodium hydrogen phosphate: 7~10g / L, melamine etherified resin: 60~100g / L, ammonium chloride: 4~5g / L, softener: 10-30g / L, penetrant JFC: 1~2g / L; the baking conditions are: 175~200℃, 30s~1min.

[0024] The beneficial effects of this invention, a flame-retardant nuclear radiation protection sound-absorbing composite board and its preparation method, are as follows: The flame-retardant nuclear radiation protection sound-absorbing board is manufactured using a non-woven processing method. The sound-absorbing layer is made of hemp fiber and low-melting-point polyester fiber, resulting in good sound absorption, high structural bending strength, simple and convenient installation and maintenance, antibacterial and moisture-proof properties, energy saving and environmental protection, and a long service life. The nuclear radiation protection layer is made of surface-modified gadolinium with high shielding performance against neutrons and gamma rays, which is electrospun into a fiber membrane with nuclear radiation protection function, providing excellent nuclear radiation protection without pollution or environmental impact. The flame-retardant layer is made of polyester fiber after flame-retardant finishing, resulting in low cost and good flame retardancy, shape retention, wear resistance, strength, and non-lint adhesion. In summary, this multifunctional sound-absorbing board is flame-retardant, provides nuclear radiation protection, absorbs and reduces noise, and is low-cost, pollution-free, stable, and lightweight, making it worthy of widespread application.

[0025] This invention combines flame retardancy and nuclear radiation protection with sound-absorbing panels. By incorporating surface-modified gadolinium oxide fibers with high shielding performance against neutrons and gamma rays, produced using electrospinning technology, and polyester fibers that have undergone flame retardant finishing, the sound-absorbing panels achieve good nuclear radiation protection and flame retardancy while absorbing sound and reducing noise. This integrates nuclear radiation protection, flame retardancy, and sound absorption, making it a multifunctional, low-cost, environmentally friendly, lightweight, and durable nonwoven product with wide applications and excellent performance. Attached Figure Description

[0026] Figure 1 A schematic diagram showing the separation of each layer in a flame-retardant, nuclear radiation-protective, sound-absorbing composite panel.

[0027] Figure 2 This is a schematic diagram showing the location of the board peeling.

[0028] Figure 3 The graph shows the effect of tensile distance on peel strength. Detailed Implementation

[0029] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0030] like Figure 1-3 As shown, a flame-retardant nuclear radiation protection sound-absorbing composite board includes a flame-retardant layer 1, a first sound-absorbing layer 2, a nuclear radiation protection layer 3, and a second sound-absorbing layer 4. The nuclear radiation protection layer 3 is a gadolinium oxide nanofiber membrane prepared by electrospinning technology using gadolinium acetate and polyvinyl alcohol as precursors.

[0031] The flame-retardant nuclear radiation protection sound-absorbing composite board described above consists of a flame-retardant layer 1, a first sound-absorbing layer 2, a nuclear radiation protection layer 3, a second sound-absorbing layer 4, and a nuclear radiation protection layer 5 arranged sequentially from top to bottom. The first and second sound-absorbing layers are made of hemp fiber and low-melting-point polyester fiber, and the layers are tightly connected by thermal bonding of low-melting-point polyester fiber.

[0032] The aforementioned flame-retardant nuclear radiation protection sound-absorbing composite board uses gadolinium oxide nanofiber membranes prepared by electrospinning and thermal oxidation of polymer PVP, metal salt Gd(CHCOOH)3 as precursor, and anhydrous ethanol as solvent.

[0033] Example 1

[0034] The preparation method of the above-mentioned flame-retardant nuclear radiation protection sound-absorbing composite material includes the following steps:

[0035] (1) Preparation of flame retardant layer: After the polyester fiber is combed, laid into a web, hot melt bonded, hot rolled into shape, it is treated with phosphorus flame retardant, dipped and rolled twice, dried, baked, washed with water and dried to obtain polyester fiber web.

[0036] (2) Preparation of gadolinium oxide fibers:

[0037] Step 1: Preparation of spinning solution. Polymer PVP and metal salt Gd(CH3COO)3 are used as raw materials, and anhydrous ethanol is used as solvent. First, a certain amount of PVP is dissolved in anhydrous ethanol, sealed and magnetically stirred for 10 minutes. After complete and uniform dissolution, Gd(CH3COO)3 powder is added, so that the mass fraction of polymer PVP is 6% and the mass fraction of Gd(CH3COO)3 is 9%. Magnetic stirring is continued for 11 hours until a completely transparent and clear solution is obtained, thus preparing the spinning precursor solution.

[0038] Step 2: Electrospinning is performed. The precursor solution is injected into the syringe. Under the action of the injection pump, the precursor solution forms droplets at the capillary opening. The receiving distance is adjusted to about 12 cm. The voltage distribution during the spinning process is controlled to be between 5KV, the ambient temperature is 20℃, and the humidity is within 10%. The charged precursor solution sprayed from the nozzle forms fibers under the action of the electric field and precipitates on the aluminum foil receiving device. Finally, PVP / Gd(CH3COO)3 composite nanofibers are collected.

[0039] Step 3: The PVP / Gd(CH3COO)3 composite fibers obtained in the above process are subjected to thermal oxidation treatment. The collected fibers are placed in a vacuum drying oven and dried for 11 hours. They are then taken out and placed in a medium-temperature tube furnace or muffle furnace for thermal oxidation treatment at a certain heating rate. Pre-oxidation treatment is carried out at 200℃, and then oxidation is carried out at 600℃ for 3 hours to finally obtain Gd2O3 nanofiber membrane.

[0040] (3) Preparation of sound-absorbing panels:

[0041] A multilayer gadolinium oxide nanofiber membrane is laminated with a polyester fiber web and heated to a temperature higher than the melting point of the low-melting-point polyester fiber to melt it into an adhesive. The adhesive is then molded at 170°C and 2 MPa, melted, and shaped to ensure a tight bond between the layers, forming a flame-retardant nuclear radiation protection sound-absorbing composite board.

[0042] In the preparation method of the above-mentioned flame-retardant nuclear radiation protection sound-absorbing composite board, in step (1), the rolling liquid rate is 80%, and the first-dip and first-rolling impregnation liquid is composed of the following components: flame retardant FRC-1: 100g / L, disodium hydrogen phosphate: 7g / L, softener: 10g / L, penetrant JFC: 1g / L, the impregnation liquid is adjusted to pH 6.5, and the second-dip and second-rolling impregnation liquid is composed of the following components: flame retardant FRC-1: 100g / L, disodium hydrogen phosphate: 7g / L, melamine etherified resin: 60g / L, ammonium chloride: 4g / L, softener: 10g / L, penetrant JFC: 1g / L; the baking conditions are: 175℃, 1min.

[0043] Example 2

[0044] The preparation method of the above-mentioned flame-retardant nuclear radiation protection sound-absorbing composite material includes the following steps:

[0045] (1) Preparation of flame retardant layer: After the polyester fiber is combed, laid into a web, hot melt bonded, hot rolled into shape, it is treated with phosphorus flame retardant, dipped and rolled twice, dried, baked, washed with water and dried to obtain polyester fiber web.

[0046] (2) Preparation of gadolinium oxide fibers:

[0047] Step 1: Preparation of spinning solution. Polymer PVP and metal salt Gd(CH3COO)3 are used as raw materials, and anhydrous ethanol is used as solvent. First, a certain amount of PVP is dissolved in anhydrous ethanol, sealed and magnetically stirred for 10 minutes. After complete and uniform dissolution, Gd(CH3COO)3 powder is added, so that the mass fraction of polymer PVP is 7% and the mass fraction of Gd(CH3COO)3 is 10%. Magnetic stirring is continued for 11.5 hours until a completely transparent and clear solution is obtained, thus preparing the spinning precursor solution.

[0048] Step 2: Electrospinning is performed. The precursor solution is injected into the syringe. Under the action of the injection pump, the precursor solution forms droplets at the capillary opening. The receiving distance is adjusted to about 12 cm. The voltage distribution during the spinning process is controlled to be between 15 KV, the ambient temperature is 20℃, and the humidity is within 15%. The charged precursor solution sprayed from the nozzle forms fibers under the action of the electric field and precipitates on the aluminum foil receiving device. Finally, PVP / Gd(CH3COO)3 composite nanofibers are collected.

[0049] Step 3: The PVP / Gd(CH3COO)3 composite fibers obtained in the above process are subjected to thermal oxidation treatment. The collected fibers are placed in a vacuum drying oven and dried for 11.5 hours. They are then taken out and placed in a medium-temperature tube furnace or muffle furnace for thermal oxidation treatment at a certain heating rate. Pre-oxidation treatment is carried out at 260℃, and then oxidation is carried out at 700℃ for 3.5 hours to finally obtain Gd2O3 nanofiber membrane.

[0050] (3) Preparation of sound-absorbing panels:

[0051] The multilayer gadolinium oxide nanofiber membrane is laminated with a polyester fiber web and heated to a temperature higher than the melting point of the low-melting-point polyester fiber to melt it into an adhesive. The adhesive is then molded at 170℃ and 2.5 MPa, melted, and shaped to ensure a tight bond between the layers, forming a flame-retardant nuclear radiation protection sound-absorbing composite board.

[0052] In the preparation method of the above-mentioned flame-retardant nuclear radiation protection sound-absorbing composite board, in step (1), the rolling liquid rate is 80%, and the first-dip and first-rolling impregnation liquid is composed of the following components: flame retardant FRC-1: 130g / L, disodium hydrogen phosphate: 8g / L, softener: 20g / L, penetrant: JFC: 1.5g / L, the impregnation liquid is adjusted to pH 6.5, and the second-dip and second-rolling impregnation liquid is composed of the following components: flame retardant FRC-1: 130g / L, disodium hydrogen phosphate: 8g / L, melamine etherified resin: 80g / L, ammonium chloride: 4.5g / L, softener: 20g / L, penetrant: JFC: 1.5g / L; the baking conditions are: 185℃, 45s.

[0053] Example 3

[0054] The preparation method of the above-mentioned flame-retardant nuclear radiation protection sound-absorbing composite material includes the following steps:

[0055] (1) Preparation of flame retardant layer: After the polyester fiber is combed, laid into a web, hot melt bonded, hot rolled into shape, it is treated with phosphorus flame retardant, dipped and rolled twice, dried, baked, washed with water and dried to obtain polyester fiber web.

[0056] (2) Preparation of gadolinium oxide fibers:

[0057] Step 1: Preparation of spinning solution. Polymer PVP and metal salt Gd(CH3COO)3 are used as raw materials, and anhydrous ethanol is used as solvent. First, a certain amount of PVP is dissolved in anhydrous ethanol, sealed and magnetically stirred for 10 minutes. After complete and uniform dissolution, Gd(CH3COO)3 powder is added, so that the mass fraction of polymer PVP is 8% and the mass fraction of Gd(CH3COO)3 is 12%. Magnetic stirring is continued for 12 hours until a completely transparent and clear solution is obtained, thus preparing the spinning precursor solution.

[0058] Step 2: Electrospinning is performed. The precursor solution is injected into the syringe. Under the action of the injection pump, the precursor solution forms droplets at the capillary opening. The receiving distance is adjusted to about 12 cm. The voltage distribution during the spinning process is controlled to be between 30 KV, the ambient temperature is 20℃, and the humidity is within 20%. The charged precursor solution sprayed from the nozzle forms fibers under the action of the electric field and precipitates on the aluminum foil receiving device. Finally, PVP / Gd(CH3COO)3 composite nanofibers are collected.

[0059] Step 3: The PVP / Gd(CH3COO)3 composite fibers obtained in the above process are subjected to thermal oxidation treatment. The collected fibers are placed in a vacuum drying oven and dried for 12 hours. They are then taken out and placed in a medium-temperature tube furnace or muffle furnace for thermal oxidation treatment at a certain heating rate. Pre-oxidation treatment is carried out at 300℃, and then oxidation is carried out at 800℃ for 4 hours to finally obtain Gd2O3 nanofiber membrane.

[0060] (3) Preparation of sound-absorbing panels:

[0061] A multilayer gadolinium oxide nanofiber membrane is laminated with a polyester fiber web and heated to a temperature higher than the melting point of the low-melting-point polyester fiber to melt it into an adhesive. The adhesive is then molded at 170°C and 3 MPa, melted, and shaped to ensure a tight bond between the layers, forming a flame-retardant, nuclear radiation-protective, and sound-absorbing composite board.

[0062] In the preparation method of the above-mentioned flame-retardant nuclear radiation protection sound-absorbing composite board, in step (1), the rolling liquid rate is 80%, and the first-dip and first-rolling impregnation liquid is composed of the following components: flame retardant FRC-1: 150g / L, disodium hydrogen phosphate: 10g / L, softener: 30g / L, penetrant JFC: 2g / L, the impregnation liquid is adjusted to pH 6.5, and the second-dip and second-rolling impregnation liquid is composed of the following components: flame retardant FRC-1: 150g / L, disodium hydrogen phosphate: 10g / L, melamine etherified resin: 100g / L, ammonium chloride: 5g / L, softener: 30g / L, penetrant JFC: 2g / L; the baking conditions are: 200℃, 30s.

[0063] The flame-retardant nuclear radiation protection sound-absorbing composite board prepared by the above preparation method has a combustion growth rate index of 23W / S, a longitudinal heat release of 2.5 MJ within 600s, a flame tip height of less than or equal to 150mm within 60s, and no phenomenon of internal combustion dripping igniting filter paper within 60s.

[0064] Its average sound absorption coefficient exceeds 0.3, which can achieve a noise reduction of 4-7dB. The highest sound absorption coefficient reaches more than 0.6 in the 125-400Hz noise range, and the sound absorption performance is good in the 400~800HZ frequency band.

[0065] Its nuclear radiation protection effect is: neutron protection coefficient (Kn) close to 7, gamma ray protection coefficient (Kr) greater than 9.

[0066] Flame-retardant, nuclear radiation-protective, sound-absorbing composite panels, 0.5-1cm thick. (Example:) Figure 2 , 3 As shown, the peel force of the board is 10N, the peel point is at 1 / 2, and there is good adhesion between the layers. It achieves integrated nuclear radiation protection, flame retardancy, and sound absorption, possessing multiple functions, low manufacturing cost, being environmentally friendly, lightweight, and durable. It is a widely used and high-performance nonwoven product.

[0067] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A method for preparing a flame-retardant nuclear radiation protection sound-absorbing composite panel, characterized in that, The flame-retardant nuclear radiation protection sound-absorbing composite board includes a flame-retardant layer, a first sound-absorbing layer, a nuclear radiation protection layer, and a second sound-absorbing layer. The nuclear radiation protection layer is a gadolinium oxide nanofiber membrane prepared using electrospinning technology. The flame-retardant layer, the first sound-absorbing layer, the nuclear radiation protection layer, the second sound-absorbing layer, and the nuclear radiation protection layer are arranged sequentially from top to bottom. The first and second sound-absorbing layers are made of hemp fiber and low-melting-point polyester fiber, and the layers are tightly connected by thermal bonding of low-melting-point polyester fiber. The gadolinium oxide nanofiber membrane is prepared by electrospinning and thermal oxidation using polymer PVP, metal salt Gd(CH3COO)3 as a precursor, and anhydrous ethanol as a solvent. The preparation method includes the following steps: (1) Preparation of flame retardant layer: After the polyester fiber is combed, laid into a web, hot melt bonded, hot rolled into shape, it is treated with phosphorus flame retardant, dipped and rolled twice, dried, baked, washed with water and dried to obtain polyester fiber web. (2) Preparation of gadolinium oxide fibers: Step 1: Preparation of spinning solution. Using polymer PVP and metal salt Gd(CH3COO)3 as raw materials and anhydrous ethanol as solvent, a certain amount of PVP is first dissolved in anhydrous ethanol. After sealing, the solution is magnetically stirred for 10 minutes. After complete and uniform dissolution, Gd(CH3COO)3 powder is added, so that the mass fraction of polymer PVP is 6-8% and the mass fraction of Gd(CH3COO)3 is 9-12%. The solution is then magnetically stirred for 11-12 hours until a completely transparent and clear solution is obtained, thus preparing the spinning precursor solution. Step 2: Electrospinning is performed. The precursor solution is injected into the syringe. Under the action of the injection pump, the precursor solution forms droplets at the capillary opening. The receiving distance is adjusted, and the voltage distribution during the spinning process is controlled between 5-30KV. The ambient temperature is 20℃ and the humidity is within the range of 10%-20%. The charged precursor solution sprayed from the nozzle forms fibers under the action of the electric field and precipitates on the aluminum foil receiving device. Finally, PVP and Gd(CH3COO)3 composite nanofibers are collected. Step 3: The PVP and Gd(CH3COO)3 composite fibers obtained in the above process are subjected to thermal oxidation treatment. The collected fibers are placed in a vacuum drying oven and dried for 11-12 hours. They are then taken out and placed in a medium-temperature tube furnace or muffle furnace for thermal oxidation treatment at a certain heating rate. Pre-oxidation treatment is carried out at 200-300℃, followed by oxidation at 600-800℃ for 3-4 hours to finally obtain Gd2O3 nanofiber membrane. (3) Preparation of sound-absorbing panels: A multilayer gadolinium oxide nanofiber membrane is laminated with a polyester fiber web and heated to a temperature higher than the melting point of the low-melting-point polyester fiber to melt it into an adhesive. The adhesive is then molded at 170℃ and 2-3 MPa, melted, and shaped to ensure a tight bond between the layers, forming a flame-retardant, nuclear radiation-protective, and sound-absorbing composite board.

2. The method for preparing the flame-retardant nuclear radiation protection sound-absorbing composite material according to claim 1, characterized in that, In step (1), the rolling yield is 80%, and the first-dip and first-nip rolling solution consists of the following components: flame retardant FRC-1: 100-150g / L, disodium hydrogen phosphate: 7-10g / L, softener: 10-30g / L, penetrant JFC: 1-2g / L, and the rolling solution is adjusted to pH 6.

5. The second-dip and second-nip rolling solution consists of the following components: flame retardant FRC-1: 100-150g / L, disodium hydrogen phosphate: 7-10g / L, melamine etherified resin: 60-100g / L, ammonium chloride: 4-5g / L, softener: 10-30g / L, penetrant JFC: 1-2g / L; the baking conditions are: 175-200℃, 30s-1min.

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