Flame-retardant sound-insulation cotton and preparation method thereof

Abstract

The invention relates to the field of sound insulation cotton, in particular to flame-retardant sound insulation cotton and a preparation method thereof. The flame-retardant sound insulation cotton is prepared from the following raw materials in parts by mass: 50 to 80 parts of polyether polyurethane, 10 to 20 parts of acrylic fiber, 1 to 5 parts of [3-(trimethoxysilyl) propyl] succinic anhydride, 5 to 15 parts of modified expanded vermiculite, 3 to 8 parts of binder, 2 to 5 parts of foaming agent, 0.5 to 3 parts of curing agent, 0.1 to 1 part of antioxidant and 0.1 to 0.5 part of initiator. According to the flame-retardant sound-insulation cotton, the sound insulation effect of the flame-retardant sound-insulation cotton is remarkably improved through multiple mechanisms of enhancing the damping performance of the material, improving reflection and scattering of sound waves, optimizing the porous structure, improving the mechanical property and stability, reducing the propagation speed of the sound waves and the like, and meanwhile the flame-retardant sound-insulation cotton has the excellent flame-retardant performance.

Description

Technical Field

[0001] The present invention relates to the field of sound insulation cotton, and specifically, to a flame-retardant sound insulation cotton and a preparation method thereof. Background Art

[0002] In today's society, with the rapid development of industrialization and urbanization, noise pollution has become an important environmental problem affecting people's quality of life and work efficiency. To effectively reduce noise, various sound insulation materials have emerged and been widely used. However, the existing sound insulation materials in the prior art often have some deficiencies and are difficult to meet the growing high-performance sound insulation requirements. On the one hand, many traditional sound insulation materials, such as polyether-type polyurethane foam, although having certain sound insulation performance, their damping performance and the ability to reflect and scatter sound waves are limited. When facing medium and high-frequency noise, the sound insulation effect is not ideal, and a part of the sound wave energy can still penetrate the material, resulting in poor sound insulation effect. On the other hand, although some enhanced sound insulation materials improve the sound insulation performance by adding fibers or particles, the compatibility of these materials with the matrix is often poor. This not only affects the processing performance of the material but also easily causes defects inside the material, instead reducing the sound insulation effect. In addition, some existing sound insulation materials also have deficiencies in mechanical properties, thermal stability, and durability, restricting their application in complex environments and long-term use. In addition, some sound insulation materials have deficiencies in mechanics, thermal stability, and durability, restricting their application scope.

[0003] Therefore, how to develop a high-performance sound insulation material that can effectively solve the above problems has become a difficult problem that needs to be overcome by those skilled in the art. Summary of the Invention

[0004] In view of this, the present invention is committed to providing a flame-retardant sound insulation cotton and a preparation method thereof, and the flame-retardant sound insulation cotton has excellent sound insulation and flame-retardant properties.

[0005] To solve the above technical problems, the present application is implemented as follows: The present invention provides a flame-retardant sound insulation cotton, comprising the following raw materials in parts by mass: 50 - 80 parts of polyether-type polyurethane, 10 - 20 parts of acrylic fiber, 1 - 5 parts of [3-(trimethoxysilyl)propyl] succinic anhydride, 5 - 15 parts of modified expanded vermiculite, 3 - 8 parts of binder, 2 - 5 parts of foaming agent, 0.5 - 3 parts of curing agent, 0.1 - 1 part of antioxidant, and 0.1 - 0.5 part of first initiator.

[0006] Preferably, in the above-mentioned flame-retardant sound insulation cotton, the preparation method of the modified expanded vermiculite comprises the following steps: S10. Calcinate vermiculite to obtain expanded vermiculite; S20. Mix expanded vermiculite and hydrochloric acid, then add an ethanol solution of sulfanilamide and mix for reaction to obtain an intermediate; S30. Mix piperazine pyrophosphate, boric acid diglyceride, the intermediate and toluene, then add a second initiator and toluene and mix for reaction to obtain modified expanded vermiculite.

[0007] Preferably, in the above-mentioned flame-retardant sound-insulating cotton, in step S10, the calcination temperature is 850 - 1000 °C, and the calcination time is 45 - 60 s.

[0008] Preferably, in the above-mentioned flame-retardant sound-insulating cotton, in step S20, the concentration of the hydrochloric acid is 35 - 37 wt%; In step S20, the dosage ratio of the expanded vermiculite to the hydrochloric acid is 50 - 60 g : 150 - 200 mL; In step S20, the mass ratio of the expanded vermiculite to sulfanilamide in the ethanol solution of sulfanilamide is 50 - 60 : 15 - 25; In step S20, the concentration of the ethanol solution of sulfanilamide is 15 - 20 wt%; In step S20, the reaction temperature is 50 - 60 °C, and the reaction time is 4 - 6 h.

[0009] Preferably, in the above-mentioned flame-retardant sound-insulating cotton, in step S30, the mass ratio of piperazine pyrophosphate to boric acid diglyceride is 10 : 5 - 8; In step S30, the dosage ratio of piperazine pyrophosphate to toluene is 10 g : 100 - 120 mL; In step S30, the mass ratio of piperazine pyrophosphate to the intermediate is 10 : 100 - 120; In step S30, the mass ratio of piperazine pyrophosphate to the second initiator is 10 : 0.1 - 0.3; In step S30, the second initiator includes azobisisobutyronitrile; In step S30, the reaction temperature is 70 - 80 °C, the reaction time is 8 - 10 h, and the reaction atmosphere is nitrogen.

[0010] Preferably, in the above-mentioned flame-retardant sound-insulating cotton, the binder includes at least one of polyvinyl alcohol, polyorthoester, polycaprolactone and polyglycerol sebacate; The foaming agent includes any one of cyclopentane, n-pentane, isopentane, hexane; The curing agent includes epoxy resin; The antioxidant includes n-octadecyl 3,5-di-tert-butyl-4-hydroxyhydrocinnamate and / or pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]; The initiator includes benzoyl peroxide.

[0011] The present invention also provides a preparation method of a flame-retardant sound-insulating cotton, comprising the following steps: S1. Mix [3-(trimethoxysilyl)propyl]succinic anhydride and toluene, then add a first initiator and mix to obtain a dispersion; soak acrylic fibers in the dispersion and react to obtain a first product; S2. Mix polyether-type polyurethane, a binder and an antioxidant and disperse them, then add modified expanded vermiculite and the first product and disperse to obtain a second product; S3. Mix the second product, a foaming agent and a curing agent and disperse them, then carry out foaming and curing to obtain the flame-retardant sound-insulating cotton.

[0012] Preferably, in the above-mentioned flame-retardant sound-insulating cotton, in step S1, the reaction temperature is 70-90°C and the reaction time is 4-6 h.

[0013] Preferably, in the above-mentioned flame-retardant sound-insulating cotton, in step S3, the foaming temperature is 80-100°C and the foaming time is 1-2 h; In step S3, the curing temperature is 100-120°C and the curing time is 2-4 h.

[0014] The mechanism of action in the present invention: 1. For the flame-retardant sound insulation cotton provided by the present invention, under the action of an initiator, acrylic fibers are activated, and [3-(trimethoxysilyl)propyl] succinic anhydride hydrolyzes to form silanol, which reacts with the hydroxyl groups on the surface of the activated acrylic fibers to form stable covalent bonds, enabling [3-(trimethoxysilyl)propyl] succinic anhydride to be grafted onto the acrylic fibers. The grafted acrylic fibers have better compatibility with polyether-type polyurethane, can form a more uniform dispersion in the composite material, and improve the overall performance of the material. At the same time, polyether-type polyurethane itself has certain elasticity and flexibility, which can cause the vibration of the material during the propagation of sound waves. After grafting [3-(trimethoxysilyl)propyl] succinic anhydride onto the acrylic fibers and subsequent foaming, a multiphase structure and pore structure are formed. When sound waves pass through the interfaces of different phases, due to the acoustic impedance difference between the phases, sound wave reflection, refraction, and scattering will occur, increasing the propagation path of the sound waves and prolonging the residence time of the sound waves in the material, thereby improving the energy dissipation efficiency of the sound waves. At the same time, there are strong intermolecular forces between the grafted chain segments and the molecular chains of polyether-type polyurethane, including hydrogen bonds and van der Waals forces. This strong interaction makes it easier to cause friction and movement of the molecular chains when sound waves propagate inside the material, thereby increasing internal friction and converting sound energy into heat energy. These polar groups can also interact with water molecules through hydrogen bonds and other interactions to form a thin hydration layer, further enhancing the absorption of sound waves. The strong interaction between the grafted acrylic fibers and polyether-type polyurethane improves the mechanical properties of the material, including tensile strength and modulus, etc. This enhanced mechanical property makes it more difficult for the material to deform under the action of sound waves, thereby reducing the transmission of sound waves. Therefore, the flame-retardant sound insulation cotton has excellent sound insulation effects.

[0015] 2. After obtaining expanded vermiculite by calcining vermiculite, it is treated with hydrochloric acid and reacted with an ethanol solution of sulfanilamide to insert sulfanilamide into the interlayer structure of the expanded vermiculite to form an intermediate. Subsequently, piperazine pyrophosphate, diglycerol borate, and toluene are mixed, and an initiator is added for reaction, so that the phosphate group of piperazine pyrophosphate reacts with the hydroxyl groups on the vermiculite surface to form stable P-O-Si bonds, and the borate group of diglycerol borate forms borate bonds with the hydroxyl groups. At the same time, piperazine pyrophosphate and diglycerol borate are crosslinked through bifunctional groups to form a network structure to wrap the vermiculite surface, improving the stability of the modified layer; a polymer film with a crosslinked structure is formed. The modified expanded vermiculite has good flame-retardant properties and can form a dense carbon layer at high temperatures to isolate oxygen and heat and inhibit the combustion reaction.

[0016] Through the above technical solutions, the beneficial technical effects of the present invention are as follows: The flame-retardant and sound-insulating cotton provided by the present invention introduces [3-(trimethoxysilyl)propyl] succinic anhydride grafted onto acrylic fibers in polyether-type polyurethane. Through multiple mechanisms such as enhancing the damping performance of the material, improving the reflection and scattering of sound waves, optimizing the porous structure, enhancing the mechanical properties and stability, and reducing the sound wave propagation speed, the sound insulation effect of the flame-retardant and sound-insulating cotton is significantly improved. This enables the flame-retardant and sound-insulating cotton to more effectively reduce noise propagation in various application scenarios and provide better sound insulation performance. Moreover, piperazine pyrophosphate and diglycerol borate in the modified expanded vermiculite decompose when heated to generate incombustible gases and carbonaceous residues, forming a dense carbon layer that isolates oxygen and heat, effectively inhibiting the combustion reaction. At the same time, the grafted acrylic fibers can maintain good stability at high temperatures and do not produce molten droplets, further enhancing the flame-retardant effect. Detailed Embodiments

[0017] The present invention discloses a flame-retardant and sound-insulating cotton and its preparation method. Those skilled in the art can draw on the content of this article and appropriately modify the process parameters to achieve it. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art, and they are all considered to be included in the present invention. The method and application of the present invention have been described through preferred embodiments, and those related can obviously make changes or appropriate alterations and combinations to the methods and applications described herein without departing from the content, spirit, and scope of the present invention to implement and apply the technology of the present invention.

[0018] The present invention is further described in detail below through examples. All raw materials used in the examples can be obtained through commercial channels.

[0019] Example 1 Flame-retardant and sound-insulating cotton and its preparation method, including the following raw materials in parts by mass: 65 parts of polyether-type polyurethane, 15 parts of acrylic fibers, 3 parts of [3-(trimethoxysilyl)propyl] succinic anhydride, 10 parts of modified expanded vermiculite, 8 parts of binder polyvinyl alcohol, 3 parts of foaming agent cyclopentane, 2 parts of curing agent epoxy resin, 0.5 part of antioxidant β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid n-octadecyl ester, and 0.3 part of initiator benzoyl peroxide; Among them, the preparation method of the modified expanded vermiculite includes the following steps: S10. Calcinate vermiculite at 900 °C for 50 s to obtain expanded vermiculite; S20. Mix the expanded vermiculite and hydrochloric acid with a concentration of 37 wt% according to a dosage ratio of 60 g:200 mL, and then add an ethanol solution of sulfanilamide with a concentration of 20 wt%. The mass ratio of sulfanilamide in the expanded vermiculite and the ethanol solution of sulfanilamide is 60:15, and react at 60 °C for 5 h to obtain an intermediate; S30. Disperse piperazine pyrophosphate and diglycerol borate in toluene according to a mass ratio of 10:6, then add the intermediate. The dosage ratio of piperazine pyrophosphate to toluene is 10 g:120 mL. Add the initiator azobisisobutyronitrile and mix with toluene. The mass ratio of piperazine pyrophosphate to the intermediate is 10:120, and the mass ratio of piperazine pyrophosphate to the initiator is 10:0.3. React at 80 °C under nitrogen for 10 h to obtain modified expanded vermiculite.

[0020] The preparation method of the flame-retardant sound insulation cotton comprises the following steps: S1. Mix [3-(trimethoxysilyl)propyl] succinic anhydride and toluene according to a mass ratio of 3 g:50 mL, then add the initiator and mix to obtain a dispersion; soak acrylic fiber in the dispersion and react at 80 °C for 5 h to obtain the first product; S2. Mix polyether-type polyurethane, binder and antioxidant and disperse them, then add modified expanded vermiculite and the first product and disperse them to obtain the second product; S3. Mix and disperse the second product, foaming agent and curing agent, and foam at 90 °C for 2 h. Then cure at 120 °C for 3 h to obtain the flame-retardant sound insulation cotton.

[0021] Example 2 The flame-retardant sound insulation cotton and its preparation method, comprising the following raw materials in parts by mass: 60 parts of polyether-type polyurethane, 12 parts of acrylic fiber, 3 parts of [3-(trimethoxysilyl)propyl] succinic anhydride, 8 parts of modified expanded vermiculite, 3 parts of binder polyvinyl alcohol, 3 parts of foaming agent cyclopentane, 0.5 part of curing agent epoxy resin, 0.1 part of antioxidant β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid octadecyl alcohol ester and 0.1 part of initiator benzoyl peroxide; Among them, the preparation method of the modified expanded vermiculite comprises the following steps: S10. Calcinate vermiculite at 900 °C for 60 s to obtain expanded vermiculite; S20. Mix expanded vermiculite and 37 wt% hydrochloric acid according to a dosage ratio of 50 g:150 mL, then add a 20 wt% ethanol solution of sulfanilamide and mix. The mass ratio of expanded vermiculite to sulfanilamide in the ethanol solution of sulfanilamide is 50:15. React at 50 °C for 5 h to obtain the intermediate; S30. Disperse piperazine pyrophosphate and diglycerol borate in toluene according to a mass ratio of 10:6, then add the intermediate. The dosage ratio of piperazine pyrophosphate to toluene is 10 g:120 mL. Add the initiator azobisisobutyronitrile and mix with toluene. The mass ratio of piperazine pyrophosphate to the intermediate is 10:120, and the mass ratio of piperazine pyrophosphate to the initiator is 10:0.1. React at 75 °C under nitrogen for 9 h to obtain modified expanded vermiculite.

[0022] Preparation method of flame-retardant sound insulation cotton, comprising the following steps: S1. Mix [3-(trimethoxysilyl)propyl] succinic anhydride and toluene in a mass ratio of 3 g:50 mL, add an initiator and mix to obtain a dispersion; soak acrylic fiber in the dispersion and react at 80 °C for 5 h to obtain a first product; S2. Mix polyether-type polyurethane, binder and antioxidant for dispersion, then add modified expanded vermiculite and the first product for dispersion to obtain a second product; S3. Mix the second product, foaming agent and curing agent for dispersion, and perform foaming at 900 °C for 2 h. Then cure at 120 °C for 4 h to obtain the flame-retardant sound insulation cotton.

[0023] Example 3 Flame-retardant sound insulation cotton and its preparation method, comprising the following raw materials in parts by mass: 70 parts of polyether-type polyurethane, 10 parts of acrylic fiber, 5 parts of [3-(trimethoxysilyl)propyl] succinic anhydride, 5 parts of modified expanded vermiculite, 8 parts of binder polyvinyl alcohol, 3 parts of foaming agent cyclopentane, 2 parts of curing agent epoxy resin, 1 part of antioxidant β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid n-octadecyl alcohol ester and 0.5 part of initiator benzoyl peroxide; Among them, the preparation method of the modified expanded vermiculite comprises the following steps: S10. Calcinate vermiculite at 900 °C for 50 s to obtain expanded vermiculite; S20. Mix expanded vermiculite and hydrochloric acid with a concentration of 37 wt% in a dosage ratio of 55 g:200 mL, then add an ethanol solution of sulfanilamide with a concentration of 20 wt%, and the mass ratio of sulfanilamide in the expanded vermiculite and the ethanol solution of sulfanilamide is 55:20, react at 60 °C for 6 h to obtain an intermediate; S30. Disperse piperazine pyrophosphate and diglycerol borate in toluene in a mass ratio of 10:8, then add the intermediate, the dosage ratio of piperazine pyrophosphate and toluene is 10 g:120 mL, add initiator azobisisobutyronitrile and toluene and mix, the mass ratio of piperazine pyrophosphate and the intermediate is 10:120, the mass ratio of piperazine pyrophosphate and the initiator is 10:0.3, react at 70 °C under nitrogen for 10 h to obtain the modified expanded vermiculite.

[0024] Preparation method of flame-retardant sound insulation cotton, comprising the following steps: S1. Mix [3-(trimethoxysilyl)propyl] succinic anhydride and toluene in a mass ratio of 3 g:50 mL, add an initiator and mix to obtain a dispersion; soak acrylic fiber in the dispersion and react at 90 °C for 4 h to obtain a first product; S2. After mixing polyether-type polyurethane, binder, and antioxidant and dispersing them, add modified expanded vermiculite and the first product and disperse to obtain the second product; S3. After mixing and dispersing the second product, foaming agent, and curing agent, conduct foaming at 100 °C for 2 h. Then cure at 120 °C for 4 h to obtain the flame-retardant sound insulation cotton.

[0025] Comparative Example 1 Flame-retardant sound insulation cotton, which is different from Example 1 in that: The vermiculite was not modified, that is, the vermiculite was calcined at 900 °C for 50 s to obtain expanded vermiculite.

[0026] The rest are the same as in Example 1.

[0027] Comparative Example 2 Flame-retardant sound insulation cotton, which is different from Example 1 in that: The preparation method of the modified expanded vermiculite includes the following steps: S10. Calcinate the vermiculite at 900 °C for 50 s to obtain expanded vermiculite; S20. After mixing the expanded vermiculite and hydrochloric acid with a concentration of 37 wt% according to a dosage ratio of 60 g:200 mL, add an ethanol solution of sulfanilamide with a concentration of 20 wt%. The mass ratio of sulfanilamide in the expanded vermiculite and the ethanol solution of sulfanilamide is 60:15, and react at 60 °C for 5 h to obtain the modified expanded vermiculite.

[0028] Comparative Example 3 Flame-retardant sound insulation cotton, which is different from Example 1 in that: [3-(Trimethoxysilyl)propyl] succinic anhydride was not added.

[0029] The rest are the same as in Example 1.

[0030] Comparative Example 4 Flame-retardant sound insulation cotton, which is different from Example 1 in that: Acrylic fiber was not added.

[0031] The rest are the same as in Example 1.

[0032] Test Example (1) Tensile strength, elongation at break: Test according to the GB / T1040.1-2018 standard, and the tensile rate is 50 mm / min; (2) Thermal conductivity: Test according to ASTM D5470; (3) Flame retardancy (limiting oxygen index): Test according to the GB / T2406.2-2009 standard, and use an oxygen index meter to measure the limiting oxygen index of the specimen. The sample size is 100 mm × 6.5 mm × 3.2 mm; (4)Sound absorption coefficient: Tested in accordance with GB / T18696.1-2004; The above test results are shown in Table 1:

[0033] As can be seen from Table 1, the flame-retardant sound-absorbing cotton of Examples 1-3 performs excellently in terms of mechanical properties, thermal conductivity, flame retardancy, and sound absorption coefficient, which benefits from the synergistic effect of components such as polyether-type polyurethane, modified expanded vermiculite, and grafted acrylic fiber. Each component cooperates with each other to achieve balance and improvement in various performance aspects of the material. The comparative examples did not add or modify the key components, resulting in a significant decline in performance, highlighting the superiority of the technical solutions of the examples.

[0034] In the ranges disclosed herein, the endpoints and any values are not limited to the exact ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values or individual point values of each range, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0035] If there is no special instruction, all embodiments and optional embodiments of the present application can be combined with each other to form new technical solutions.

[0036] If there is no special instruction, all technical features and optional technical features of the present application can be combined with each other to form new technical solutions.

[0037] If there is no special instruction, the "including" and "comprising" mentioned in the present application mean open-ended, and can also be closed-ended. For example, the "including" and "comprising" can mean that other components not listed can also be included or comprised, or only the components listed can be included or comprised.

[0038] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A flame-retardant sound-insulating cotton, characterized in that, It comprises raw materials in the following parts by mass: 50 - 80 parts of polyether-type polyurethane, 10 - 20 parts of acrylic fiber, 1 - 5 parts of [3-(trimethoxysilyl)propyl] succinic anhydride, 5 - 15 parts of modified expanded vermiculite, 3 - 8 parts of binder, 2 - 5 parts of foaming agent, 0.5 - 3 parts of curing agent, 0.1 - 1 part of antioxidant and 0.1 - 0.5 part of first initiator.

2. The flame-retardant sound-insulating cotton according to claim 1, characterized in that, The preparation method of the modified expanded vermiculite comprises the following steps: S10. Calcinate vermiculite to obtain expanded vermiculite; S20. Mix the expanded vermiculite and hydrochloric acid, then add an ethanol solution of sulfanilamide and mix to react to obtain an intermediate; S30. Mix piperazine pyrophosphate, boric acid diglyceride, the intermediate and toluene, then add a second initiator and toluene and mix to react to obtain modified expanded vermiculite.

3. The flame-retardant sound insulation cotton according to claim 2, wherein In step S10, the calcination temperature is 850 - 1000 °C and the calcination time is 45 - 60 s.

4. The flame-retardant sound insulation cotton according to claim 2, characterized in that, In step S20, the concentration of the hydrochloric acid is 35 - 37 wt%. In step S20, the dosage ratio of the expanded vermiculite to the hydrochloric acid is 50 - 60 g: 150 - 200 mL. In step S20, the mass ratio of the expanded vermiculite to sulfanilamide in the ethanol solution of sulfanilamide is 50 - 60: 15 - 25. In step S20, the concentration of the ethanol solution of sulfanilamide is 15 - 20 wt%. In step S20, the reaction temperature is 50 - 60 °C and the reaction time is 4 - 6 h.

5. The flame-retardant and sound-insulating cotton according to claim 2, wherein, In step S30, the mass ratio of piperazine pyrophosphate to boric acid diglyceride is 10: 5 - 8. In step S30, the dosage ratio of piperazine pyrophosphate to toluene is 10 g: 100 - 120 mL. In step S30, the mass ratio of piperazine pyrophosphate to the intermediate is 10: 100 - 120. In step S30, the mass ratio of piperazine pyrophosphate to the second initiator is 10: 0.1 - 0.

3. In step S30, the second initiator includes azobisisobutyronitrile. In step S30, the reaction temperature is 70 - 80 °C, the reaction time is 8 - 10 h, and the reaction atmosphere is nitrogen.

6. The flame-retardant sound-insulating cotton according to claim 1, wherein The binder includes at least one of polyvinyl alcohol, polyorthoester, polycaprolactone and polyglycerol sebacate; The foaming agent includes any one of cyclopentane, n-pentane, isopentane and hexane.

7. The flame-retardant and sound-insulating cotton according to claim 1, wherein The curing agent includes epoxy resin; The antioxidant includes n-octadecyl 3,5-di-tert-butyl-4-hydroxybenzoate and / or pentaerythritol tetra[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]; The initiator includes benzoyl peroxide.

8. A method for preparing a flame-retardant sound-insulating cotton, which is used to prepare the flame-retardant sound-insulating cotton according to any one of claims 1 to 7, characterized in that, It comprises the following steps: S1. Mix [3-(trimethoxysilyl)propyl] succinic anhydride and toluene, then add the first initiator and mix to obtain a dispersion; soak the acrylic fiber in the dispersion and react to obtain a first product; S2. Mix polyether-type polyurethane, binder and antioxidant and disperse, then add modified expanded vermiculite and the first product and disperse to obtain a second product; S3. After mixing and dispersing the second product, the foaming agent and the curing agent, carry out foaming and curing to obtain the flame-retardant sound insulation cotton.

9. The preparation method of the flame-retardant sound insulation cotton according to claim 8, characterized in that, In step S1, the temperature of the reaction is 70-90 °C, and the time of the reaction is 4-6 h.

10. The preparation method of the flame-retardant sound insulation cotton according to claim 7, characterized in that, In step S3, the temperature of the foaming is 80-100 °C, and the time of the foaming is 1-2 h; In step S3, the temperature of the curing is 100-120 °C, and the time of the curing is 2-4 h.

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