A sound insulating material composition

Abstract

The application discloses a sound insulation material composition, which comprises the following components in parts by weight: a composite base material 40-60 parts, an organic-inorganic composite damping agent 15-25 parts, a pore adjusting agent 8-15 parts, a compatilizer 4-8 parts, a lubricant 1-3 parts, and an antioxidant 0.5-2 parts; wherein the composite base material is mainly composed of polyvinyl chloride and is compounded with acetylated modified lignin to construct an environmentally-friendly mechanical skeleton; the organic-inorganic composite damping agent is compounded by butyl rubber and CTAB intercalated modified montmorillonite to strengthen the broadband damping performance; and the pore adjusting agent is compounded by modified hollow glass microbeads and alkali-treated modified corn straw to precisely control the pore structure. The sound insulation material composition produced by the application realizes the unification of broadband sound insulation, excellent mechanical properties and environmental protection, and the raw materials contain renewable biomass components, are green and pollution-free, and are widely applied.

Description

Technical Field

[0001] This invention relates to the field of sound insulation materials, and particularly to a sound insulation material composition. Background Technology

[0002] With the rapid development of industry, transportation, and urban construction, noise pollution has become a significant environmental problem affecting people's quality of life and health. Therefore, sound insulation materials are widely used in construction, transportation, and home appliances, with their core function being to reduce noise pollution by absorbing or blocking sound wave propagation. Currently, sound insulation materials on the market are mainly divided into three categories: polymer-based, inorganic-based, and composite-based. Among these, polymer materials are the most widely used due to their high plasticity, ease of processing, and low cost.

[0003] However, existing polymer-based sound insulation materials have technical drawbacks. First, they have poor sound insulation performance in the mid-to-low frequency range. Traditional single-substrate materials (such as pure PVC and PP) have low damping factors and are insufficient in blocking mid-to-low frequency sound waves in the range of 20-500Hz, with sound insulation generally below 25dB. Second, it is difficult to balance mechanical properties and sound insulation performance. In order to improve the sound insulation effect, a large amount of porosilicate is often added, which leads to a significant reduction in the tensile strength of the material and easy breakage. Third, they are not environmentally friendly. Most materials rely on all-petroleum-based substrates, and the added damping agents (such as phthalates) pose environmental risks, which do not meet the current requirements for green development.

[0004] Therefore, this application provides a polymer-based sound insulation material composition that combines wide-band sound insulation, excellent mechanical properties, and environmental friendliness. Summary of the Invention

[0005] The purpose of this invention is to provide a polymer-based sound insulation material composition that combines wide-band sound insulation, excellent mechanical properties, and environmental friendliness, and can be widely used in construction, transportation, home appliances and other fields.

[0006] The present invention provides a sound insulation material composition comprising the following components in parts by weight: 40-60 parts of composite substrate, 15-25 parts of organic-inorganic composite damping agent, 8-15 parts of pore regulator, 4-8 parts of compatibilizer, 1-3 parts of lubricant, and 0.5-2 parts of antioxidant;

[0007] The composite substrate is a mixture of polyvinyl chloride and modified lignin in a mass ratio of 2~3:1;

[0008] The organic-inorganic composite damping agent is a compound of butyl rubber and modified montmorillonite, with a mass ratio of 3~5:1.

[0009] The pore regulator is a mixture of modified hollow glass microspheres and modified corn stalks at a mass ratio of 1 to 2:1.

[0010] As a preferred technical solution of the present invention, the method for preparing the modified lignin is as follows: industrial lignin and deionized water are mixed at a mass ratio of 1:10, stirred for 30 minutes, and then filtered to obtain a filter cake. The filter cake is washed with deionized water 2-3 times, and then placed in a vacuum drying oven at 60-80℃ to dry for 8-12 hours. After pulverizing, it is passed through a 100-120 mesh sieve to obtain purified lignin. The purified lignin is mixed with acetic acid at a mass ratio of 1:5-8, stirred evenly, and then acetic anhydride is added dropwise. The mixture is stirred at 60-80℃ and a speed of 300-500 rpm for 2-4 hours. After the reaction is completed, the reaction solution is poured into ice water with a volume of 10 times that of the reaction solution, allowed to stand for 25-30 minutes, filtered, and the precipitate is collected. The precipitate is washed with deionized water 2-3 times, and then washed with a 50% ethanol solution 1-2 times. After washing, the precipitate is placed in a vacuum drying oven at 60-70℃ to dry for 6-10 hours, pulverized, and passed through a 100 mesh sieve to obtain modified lignin.

[0011] As a preferred embodiment of the present invention, the mass ratio of acetic anhydride to purified lignin is 1.5~2.5:1.

[0012] As a preferred embodiment of the present invention, the modified montmorillonite is prepared by: mixing sodium-based montmorillonite with deionized water at a mass ratio of 1:10-15, stirring at 60-70°C and 300-500 rpm for 1 hour to form a uniform suspension; washing the suspension 2-3 times with deionized water, centrifuging the washed montmorillonite suspension at 8000 rpm for 10-15 minutes, collecting the lower solid layer to obtain purified montmorillonite; mixing the purified montmorillonite with deionized water at a mass ratio of 1:10-12, and stirring at 70-80°C for 30 minutes. After 35 minutes, a uniformly dispersed montmorillonite suspension is formed. A 1-1.5% CTAB solution is slowly added dropwise to the montmorillonite suspension while maintaining the temperature at 70-80℃ and stirring at 400-600 rpm for 2-3 hours. After the reaction is complete, the mixture is centrifuged at 8000 rpm for 10 minutes, and the lower solid layer is collected. The solid is then washed 2-3 times with deionized water, and the washed solid is dried in a vacuum drying oven at 60-70℃ for 10-12 hours. After grinding, it is passed through a 200-mesh sieve to obtain CTAB intercalated modified montmorillonite.

[0013] As a preferred embodiment of the present invention, the mass ratio of the CTAB solution with a mass concentration of 1~1.5% to the purified montmorillonite is 0.2~0.3:1.

[0014] As a preferred technical solution of the present invention, the method for preparing the modified hollow glass microspheres is as follows: prepare hollow glass microspheres with a particle size of 50~100μm for later use; add 0.5~2% by weight of silane coupling agent KH-550 to a 95% ethanol solution, wherein the amount of 95% ethanol solution is 15~20 times the weight of the hollow glass microspheres; then adjust the pH of the solution to 4~5.5 with glacial acetic acid; stir at room temperature for 20~30min; then add the hollow glass microspheres; place in a constant temperature water bath at 60~80℃; stir at 100~300rpm for 1.5~3h; after the reaction is complete, filter using a Buchner funnel; wash the filter cake 2~3 times with anhydrous ethanol; then place the filter cake in an oven and dry at 80~100℃ for 3~4h; after drying, gently stir to obtain surface-modified hollow glass microspheres.

[0015] As a preferred technical solution of the present invention, the preparation method of the modified corn stalk is as follows: the dried corn stalk is crushed and passed through an 80-mesh sieve, and mixed with a 5% sodium hydroxide aqueous solution at a mass ratio of 1:15~20. The mixture is stirred at 200 rpm for 2 hours in a constant temperature water bath at 70°C. After the reaction is complete, the mixture is filtered through a Buchner funnel to obtain a filter cake. The filter cake is washed 2~3 times with deionized water. The washed filter cake is placed in a forced-air drying oven and dried at 70~75°C for 24 hours until constant weight. The dried filter cake is ground and passed through a 100-mesh sieve to obtain the surface-modified corn stalk.

[0016] As a preferred embodiment of the present invention, the compatibilizer is maleic anhydride-grafted polypropylene.

[0017] As a preferred embodiment of the present invention, the lubricant is a mixture of stearic acid and zinc stearate in a mass ratio of 1:1.

[0018] As a preferred embodiment of the present invention, the antioxidant is obtained by compounding antioxidant 1010 and antioxidant 168 at a mass ratio of 1:0.5.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] 1. This invention uses a blend of polyvinyl chloride (PVC) and acetylated modified lignin to obtain a composite substrate. PVC, as a thermoplastic resin, possesses excellent mechanical rigidity, processing fluidity, and weather resistance, providing stable structural support for the sound insulation material and ensuring its morphological integrity during molding. It also imparts impact resistance and anti-aging properties, adapting to the environmental requirements of different application scenarios. Acetylation modification of lignin reduces surface polarity, significantly improving its interfacial compatibility with PVC. This effectively avoids the problem of easy separation between unmodified lignin and synthetic resin, resulting in a more uniform internal structure and fewer mechanical weaknesses in the composite substrate. The combination of these two materials creates a synergistic effect of "rigidity-reinforcement." The structural stability of PVC combined with the natural porous structure and rigidity of modified lignin enhances the tensile strength and dimensional stability of the material. Furthermore, the porous structure of lignin absorbs sound waves, enhancing the sound insulation and attenuation effect, especially for blocking low- and mid-frequency noise. Furthermore, lignin, as an industrial byproduct, can be recycled, which not only reduces the overall cost of materials but also reduces the amount of plastic used, aligning with environmental and sustainable trends and meeting the needs of large-scale production and practical applications.

[0021] 2. This invention combines organic butyl rubber with inorganic modified montmorillonite to obtain a composite damping agent. Through the synergistic effect of the organic and inorganic phases, the overall performance of the sound insulation material is comprehensively improved. Butyl rubber possesses excellent viscoelasticity and high damping characteristics. When its molecular chains are subjected to sound waves or vibrations, they can efficiently absorb energy through chain segment friction and deformation, achieving vibration attenuation and sound wave blocking. Meanwhile, the CTAB-intercalated modified montmorillonite has a fully extended interlayer structure and significantly improved dispersibility. It forms a stable interfacial bond with butyl rubber, and its nanoscale layered structure can also construct multiple physical barriers, further extending the transmission path of sound waves and vibrations and enhancing the damping and noise reduction effect. The combination of these two phases effectively broadens the damping temperature range and frequency band of the material, ensuring stable sound insulation performance under different operating temperatures and sound wave frequencies, solving the problem of limited applicability of single organic or inorganic damping agents. Meanwhile, the inorganic rigid skeleton of modified montmorillonite can compensate for the shortcomings of butyl rubber in mechanical properties, significantly improving the tensile strength, hardness, and dimensional stability of the sound insulation material, avoiding a decrease in sound insulation effect due to deformation during use, and extending the service life of the material. In addition, the intercalation modification of montmorillonite optimizes its compatibility with the organic phase, effectively preventing component agglomeration and ensuring the uniformity of the damping effect.

[0022] 3. This invention combines modified hollow glass microspheres with modified corn stalks. Through the synergistic effect of the two components, a uniform and well-connected porous structure can be constructed within the material. This porous morphology can effectively capture and attenuate sound waves of different frequencies, prolong the sound wave propagation path, and consume sound energy, significantly improving the overall sound absorption and sound insulation effect of the material and overcoming the limitations of single-substrate sound insulation bands. The hollow structure of the modified hollow glass microspheres also has lightweight characteristics. Combined with biomass-derived corn stalks, the overall density of the material can be reduced without compromising the sound insulation effect. At the same time, the resource utilization of corn stalks enhances the material's environmental friendliness and cost advantage. Furthermore, after targeted modification treatment, the surface activity of both components is enhanced, enabling them to form good compatibility with composite substrates, damping agents, and other components, avoiding agglomeration and ensuring uniform pore distribution. This maintains the mechanical stability of the material and further optimizes the vibration reduction and sound insulation synergy with the damping agent, making the material more flexible in application while maintaining practical performance. Detailed Implementation

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Corn stalks are widely available, renewable, and inexpensive. After modification, their surface hydrophilicity / hydrophobicity and interfacial bonding ability are optimized, resulting in uniform and easily dispersed particles. The addition of modified corn stalks and modified hollow glass microspheres forms a pore regulator that synergistically regulates the internal pore structure of the material, improving sound insulation performance through pore damping and sound absorption effects. Its lightweight properties reduce the overall density of the material, improving its processability. As a natural biomass component, it reduces the amount of chemical raw materials used, enhancing the material's environmental friendliness and lowering production costs. Working synergistically with composite substrates and organic-inorganic composite damping agents, it ensures that the sound insulation material possesses both excellent sound insulation performance and practical capabilities.

[0025] Montmorillonite is a natural layered silicate mineral. After CTAB intercalation modification, it is compounded with butyl rubber to form an organic-inorganic composite damping agent. Its core characteristic is its layered crystal structure. After modification, its oleophilicity is enhanced, and its compatibility with organic components is significantly improved, allowing for uniform dispersion in materials. The addition of montmorillonite synergistically optimizes sound insulation and damping performance. On one hand, its layered structure hinders the transmission of sound waves and vibrations, synergistically enhancing the damping effect of the material with butyl rubber, efficiently absorbing sound wave energy, and improving sound insulation. On the other hand, as an inorganic reinforcing phase, it improves the mechanical strength and thermal stability of the material. Working synergistically with composite substrates, pore regulators, and other components, it improves the overall compatibility and structural stability of the material, ensuring the durability of sound insulation performance, while enriching the material's functional properties to meet the application requirements of sound insulation materials.

[0026] Lignin is a natural aromatic polymer found in plant cell walls. Together with cellulose and hemicellulose, it forms the plant skeleton, exhibiting structural stability, high heat resistance, and excellent rigidity. Furthermore, it is widely available, renewable, and environmentally friendly, making it a typical green biomass material. In this sound insulation material composition, lignin, after acetylation modification, is compounded with polyvinyl chloride (PVC) as a composite matrix. Utilizing its porous structure and rigidity, it works synergistically with an organic-inorganic composite damping agent to enhance the material's sound insulation and damping performance, increasing sound wave absorption and attenuation. Simultaneously, it acts as a biomass filler, replacing some synthetic resins, reducing production costs and environmental impact, aligning with green environmental protection requirements. The modified lignin shows improved compatibility with PVC, enhancing the material's mechanical strength and processing stability. Its inherent properties also help regulate the material's internal pore structure, further optimizing the sound insulation effect.

[0027] This application provides a sound insulation material composition comprising the following components in parts by weight: 40-60 parts of composite substrate, 15-25 parts of organic-inorganic composite damping agent, 8-15 parts of pore conditioner, 4-8 parts of compatibilizer, 1-3 parts of lubricant, and 0.5-2 parts of antioxidant.

[0028] All raw materials used in this invention are commercially available.

[0029] Example 1:

[0030] A sound insulation material composition comprising the following components in parts by weight: 60 parts of composite substrate, 25 parts of organic-inorganic composite damping agent, 15 parts of pore conditioner, 8 parts of compatibilizer, 3 parts of lubricant, and 2 parts of antioxidant.

[0031] The composite substrate is a mixture of polyvinyl chloride and modified lignin in a mass ratio of 3:1.

[0032] The organic-inorganic composite damping agent is a compound of butyl rubber and modified montmorillonite, with a mass ratio of 5:1.

[0033] The pore conditioner is a mixture of modified hollow glass microspheres and modified corn stalks at a mass ratio of 2:1.

[0034] The compatibilizer is maleic anhydride-grafted polypropylene.

[0035] The lubricant is a mixture of stearic acid and zinc stearate in a mass ratio of 1:1.

[0036] The antioxidant is obtained by compounding antioxidant 1010 and antioxidant 168 at a mass ratio of 1:0.5.

[0037] The modified lignin is prepared as follows: Industrial lignin is mixed with deionized water at a mass ratio of 1:10, stirred for 30 minutes, and then filtered to obtain a filter cake. The filter cake is washed three times with deionized water, and then placed in a vacuum drying oven at 80℃ for 12 hours. After pulverizing, it is passed through a 120-mesh sieve to obtain purified lignin. The purified lignin is mixed with acetic acid at a mass ratio of 1:8, stirred evenly, and then acetic anhydride (the mass ratio of acetic anhydride to purified lignin is 2.5:1) is added dropwise. The mixture is stirred at 80℃ and 500 rpm for 4 hours. After the reaction is completed, the reaction solution is poured into ice water at a volume 10 times that of the reaction solution, allowed to stand for 30 minutes, filtered, and the precipitate is collected. The precipitate is washed three times with deionized water, and then washed twice with a 50% ethanol solution. After washing, the precipitate is placed in a vacuum drying oven at 70℃ for 10 hours, pulverized, and passed through a 100-mesh sieve to obtain modified lignin.

[0038] The preparation method of modified montmorillonite is as follows: Sodium-based montmorillonite and deionized water are mixed at a mass ratio of 1:15 and stirred at 70℃ and 500 rpm for 1 hour to form a uniform suspension; the suspension is washed three times with deionized water, and the washed montmorillonite suspension is centrifuged at 8000 rpm for 15 minutes, and the lower solid layer is collected to obtain purified montmorillonite; the purified montmorillonite is mixed with deionized water at a mass ratio of 1:12 and stirred at 80℃ for 35 minutes to form a uniformly dispersed montmorillonite suspension; the mass... A 1.5% CTAB solution (the mass ratio of CTAB solution to purified montmorillonite was 0.3:1) was slowly added dropwise to the montmorillonite suspension. The temperature was maintained at 80℃, and the mixture was stirred at 600 rpm for 3 hours. After the reaction was completed, the mixture was centrifuged at 8000 rpm for 10 minutes, and the lower solid layer was collected. The solid was then washed three times with deionized water. The washed solid was placed in a vacuum drying oven at 70℃ and dried for 12 hours. After grinding, it was passed through a 200-mesh sieve to obtain CTAB intercalated modified montmorillonite.

[0039] The modified hollow glass microspheres were prepared as follows: Hollow glass microspheres with a particle size of 100 μm were prepared for later use; 2% by weight of silane coupling agent KH-550 of the hollow glass microspheres was added to a 95% ethanol solution, wherein the amount of 95% ethanol solution was 20 times the weight of the hollow glass microspheres; then the pH of the solution was adjusted to 5.5 with glacial acetic acid; the mixture was stirred at room temperature for 30 min; then the hollow glass microspheres were added; the mixture was placed in a constant temperature water bath at 80℃ and stirred at 300 rpm for 3 h; after the reaction was completed, the mixture was filtered using a Buchner funnel and the filter cake was washed three times with anhydrous ethanol; then the filter cake was placed in an oven and dried at 100℃ for 4 h; after drying, the mixture was gently stirred to obtain surface-modified hollow glass microspheres.

[0040] The modified corn stalk preparation method is as follows: dry corn stalks are crushed and passed through an 80-mesh sieve, and mixed with a 5% sodium hydroxide aqueous solution at a mass ratio of 1:20. The mixture is stirred at 200 rpm for 2 hours in a constant temperature water bath at 70℃. After the reaction is complete, the mixture is filtered through a Buchner funnel to obtain a filter cake. The filter cake is washed three times with deionized water. The washed filter cake is placed in a forced-air drying oven and dried at 75℃ for 24 hours until constant weight. The dried filter cake is ground and passed through a 100-mesh sieve to obtain surface-modified corn stalks.

[0041] Example 2:

[0042] A sound insulation material composition comprising the following components in parts by weight: 40 parts of composite substrate, 15 parts of organic-inorganic composite damping agent, 8 parts of pore conditioner, 4 parts of compatibilizer, 1 part of lubricant, and 0.5 parts of antioxidant.

[0043] The composite substrate is a mixture of polyvinyl chloride and modified lignin in a mass ratio of 2:1.

[0044] The organic-inorganic composite damping agent is a compound of butyl rubber and modified montmorillonite, with a mass ratio of 3:1.

[0045] The pore conditioner is a mixture of modified hollow glass microspheres and modified corn stalks at a mass ratio of 1:1.

[0046] The compatibilizer is maleic anhydride-grafted polypropylene.

[0047] The lubricant is a mixture of stearic acid and zinc stearate in a mass ratio of 1:1.

[0048] The antioxidant is obtained by compounding antioxidant 1010 and antioxidant 168 at a mass ratio of 1:0.5.

[0049] The modified lignin is prepared as follows: Industrial lignin is mixed with deionized water at a mass ratio of 1:10, stirred for 30 minutes, and then filtered to obtain a filter cake. The filter cake is washed twice with deionized water, and then placed in a vacuum drying oven at 60℃ for 8 hours. After pulverizing, it is passed through a 100-mesh sieve to obtain purified lignin. The purified lignin is mixed with acetic acid at a mass ratio of 1:5, stirred evenly, and then acetic anhydride (the mass ratio of acetic anhydride to purified lignin is 1.5:1) is added dropwise. The mixture is stirred at 60℃ and 300 rpm for 2 hours. After the reaction is completed, the reaction solution is poured into ice water at a volume 10 times that of the reaction solution, allowed to stand for 25 minutes, filtered, and the precipitate is collected. The precipitate is washed twice with deionized water, and then washed once with a 50% ethanol solution. After washing, the precipitate is placed in a vacuum drying oven at 60℃ for 6 hours, pulverized, and passed through a 100-mesh sieve to obtain modified lignin.

[0050] The preparation method of modified montmorillonite is as follows: Sodium-based montmorillonite and deionized water are mixed at a mass ratio of 1:10 and stirred at 60℃ and 300 rpm for 1 hour to form a uniform suspension; the suspension is washed twice with deionized water, and the washed montmorillonite suspension is centrifuged at 8000 rpm for 10 minutes, and the lower solid layer is collected to obtain purified montmorillonite; the purified montmorillonite is mixed with deionized water at a mass ratio of 1:10 and stirred at 70℃ for 30 minutes to form a uniformly dispersed montmorillonite suspension; A 1% CTAB solution (with a CTAB solution to purified montmorillonite mass ratio of 0.2:1) was slowly added dropwise to the montmorillonite suspension. The temperature was maintained at 70℃, and the mixture was stirred at 400 rpm for 2 hours. After the reaction was completed, the mixture was centrifuged at 8000 rpm for 10 minutes, and the lower solid layer was collected. The solid was then washed twice with deionized water, and the washed solid was dried in a vacuum drying oven at 60℃ for 10 hours. After grinding, the solid was passed through a 200-mesh sieve to obtain CTAB intercalated modified montmorillonite.

[0051] The modified hollow glass microspheres were prepared as follows: Hollow glass microspheres with a particle size of 50 μm were prepared for later use; 0.5% by weight of silane coupling agent KH-550 was added to a 95% ethanol solution, wherein the amount of 95% ethanol solution was 15 times the mass of the hollow glass microspheres; then the pH of the solution was adjusted to 4 with glacial acetic acid; the mixture was stirred at room temperature for 20 min; then the hollow glass microspheres were added; the mixture was placed in a constant temperature water bath at 60℃ and stirred at 100 rpm for 1.5 h; after the reaction was completed, the mixture was filtered using a Buchner funnel and the filter cake was washed twice with anhydrous ethanol; then the filter cake was placed in an oven and dried at 80℃ for 3 h; after drying, the mixture was gently stirred to obtain surface-modified hollow glass microspheres.

[0052] The modified corn stalk preparation method is as follows: dry corn stalks are crushed and passed through an 80-mesh sieve, and mixed with a 5% sodium hydroxide aqueous solution at a mass ratio of 1:15. The mixture is stirred at 200 rpm for 2 hours in a constant temperature water bath at 70℃. After the reaction is complete, the mixture is filtered through a Buchner funnel to obtain a filter cake. The filter cake is washed twice with deionized water. The washed filter cake is placed in a forced-air drying oven and dried at 70℃ for 24 hours until constant weight. The dried filter cake is ground and passed through a 100-mesh sieve to obtain surface-modified corn stalks.

[0053] Example 3:

[0054] A sound insulation material composition comprising the following components in parts by weight: 50 parts of composite substrate, 20 parts of organic-inorganic composite damping agent, 12 parts of pore conditioner, 6 parts of compatibilizer, 2 parts of lubricant, and 1.3 parts of antioxidant.

[0055] The composite substrate is a mixture of polyvinyl chloride and modified lignin at a mass ratio of 2.5:1.

[0056] The organic-inorganic composite damping agent is a compound of butyl rubber and modified montmorillonite, with a mass ratio of 4:1.

[0057] The pore conditioner is a mixture of modified hollow glass microspheres and modified corn stalks at a mass ratio of 1.5:1.

[0058] The compatibilizer is maleic anhydride-grafted polypropylene.

[0059] The lubricant is a mixture of stearic acid and zinc stearate in a mass ratio of 1:1.

[0060] The antioxidant is obtained by compounding antioxidant 1010 and antioxidant 168 at a mass ratio of 1:0.5.

[0061] The modified lignin is prepared as follows: Industrial lignin is mixed with deionized water at a mass ratio of 1:10, stirred for 30 minutes, and then filtered to obtain a filter cake. The filter cake is washed three times with deionized water, and then placed in a vacuum drying oven at 70℃ for 10 hours. After pulverizing, it is passed through a 120-mesh sieve to obtain purified lignin. The purified lignin is mixed with acetic acid at a mass ratio of 1:6, stirred evenly, and then acetic anhydride (the mass ratio of acetic anhydride to purified lignin is 2:1) is added dropwise. The mixture is stirred at 70℃ and 400 rpm for 3 hours. After the reaction is completed, the reaction solution is poured into 10 times the volume of ice water, allowed to stand for 27 minutes, filtered, and the precipitate is collected. The precipitate is washed three times with deionized water, and then washed twice with a 50% ethanol solution. After washing, the precipitate is placed in a vacuum drying oven at 65℃ for 8 hours, pulverized, and passed through a 100-mesh sieve to obtain modified lignin.

[0062] The preparation method of modified montmorillonite is as follows: Sodium-based montmorillonite and deionized water are mixed at a mass ratio of 1:12 and stirred at 65℃ and 400 rpm for 1 hour to form a uniform suspension; the suspension is washed three times with deionized water, and the washed montmorillonite suspension is centrifuged at 8000 rpm for 12 minutes, and the lower solid layer is collected to obtain purified montmorillonite; the purified montmorillonite is mixed with deionized water at a mass ratio of 1:11 and stirred at 75℃ for 32 minutes to form a uniformly dispersed montmorillonite suspension; the mass concentration is... A 1.2% CTAB solution (the mass ratio of CTAB solution to purified montmorillonite was 0.25:1) was slowly added dropwise to the montmorillonite suspension. The temperature was maintained at 75℃, and the mixture was stirred at 500 rpm for 2.5 h. After the reaction was completed, the mixture was centrifuged at 8000 rpm for 10 min, and the lower solid layer was collected. The solid was then washed three times with deionized water. The washed solid was placed in a vacuum drying oven at 65℃ and dried for 11 h. After grinding, it was passed through a 200-mesh sieve to obtain CTAB intercalated modified montmorillonite.

[0063] The modified hollow glass microspheres were prepared as follows: Hollow glass microspheres with a particle size of 100 μm were prepared for later use; 1.5% by weight of silane coupling agent KH-550 was added to a 95% ethanol solution, wherein the amount of 95% ethanol solution was 17 times the mass of the hollow glass microspheres; then the pH of the solution was adjusted to 5 with glacial acetic acid; the mixture was stirred at room temperature for 25 min; then the hollow glass microspheres were added; the mixture was placed in a constant temperature water bath at 70℃ and stirred at 200 rpm for 2.5 h; after the reaction was completed, the mixture was filtered using a Buchner funnel and the filter cake was washed three times with anhydrous ethanol; then the filter cake was placed in an oven and dried at 90℃ for 3.5 h; after drying, the mixture was gently stirred to obtain surface-modified hollow glass microspheres.

[0064] The modified corn stalk preparation method is as follows: dry corn stalks are crushed and passed through an 80-mesh sieve, and mixed with a 5% sodium hydroxide aqueous solution at a mass ratio of 1:17. The mixture is stirred at 200 rpm for 2 hours in a constant temperature water bath at 70℃. After the reaction is complete, the mixture is filtered through a Buchner funnel to obtain a filter cake. The filter cake is washed three times with deionized water. The washed filter cake is placed in a forced-air drying oven and dried at 72℃ for 24 hours until constant weight. The dried filter cake is ground and passed through a 100-mesh sieve to obtain surface-modified corn stalks.

[0065] Comparative Example 1:

[0066] The difference from Example 1 is that the modified lignin in the composite substrate is removed.

[0067] Comparative Example 2:

[0068] The difference from Example 1 is that the modified montmorillonite in the organic-inorganic composite damping agent is removed.

[0069] Comparative Example 3:

[0070] The difference from Example 1 is that the modified corn stalks in the pore conditioner are removed.

[0071] The performance of the sound insulation material compositions prepared in Examples 1, 2, and 3 and Comparative Examples 1, 2, and 3 was tested.

[0072] The sound insulation material compositions prepared in Examples 1, 2, and 3 and Comparative Examples 1, 2, and 3 were melt-blended in a twin-screw extruder at 150°C and extruded into granules. The granules were then molded into sheets at 160°C and 15 MPa, held at that temperature and pressure for 6 minutes, and then cooled and demolded to obtain sound insulation sheet materials. The sound insulation performance of the sound insulation sheets of the examples and comparative examples was tested according to standard GB / T18696.2-2002, and the test results are shown in Table 1. The tensile strength of the sound insulation sheet materials prepared in the examples and comparative examples was tested using standard GB / T1040.1-2025. The combustion behavior of the sound insulation sheets of the examples and comparative examples was determined using the oxygen index method for plastics disclosed in standard GB / T2406.3-2022. High temperature resistance: After maintaining at 80°C for 100 hours, the product was observed for obvious deformation or softening; no deformation or softening indicated excellent quality; deformation or softening indicated failure. Low-temperature resistance: After maintaining at -20℃ for 2 hours and bending at this temperature 180°, observe whether the product cracks; if the product does not crack, it is excellent; if the product cracks, it is unqualified. The test results are shown in Table 2.

[0073] Table 1: Sound insulation performance tests of the sound insulation sheets prepared in the examples and comparative examples

[0074]

[0075] As can be seen from Table 1, the sound insulation sheet prepared by adding modified lignin, modified montmorillonite and modified corn stalk to the sound insulation material composition of the present invention has a good sound insulation effect, and the sound insulation sheet prepared by the example group has a significantly greater sound insulation volume than the sound insulation sheet in the comparative example group.

[0076] Table 2: Performance Tests of Sound Insulation Sheets Prepared in Examples and Comparative Examples

[0077]

[0078] As can be seen from Table 2, the sound insulation material composition prepared in the example group of the present invention not only has a good sound insulation effect, but also maintains good high oxygen content, mechanical strength and weather resistance.

[0079] After acetylation, modified lignin exhibits significantly improved compatibility with PVC. As a composite substrate, it enhances interfacial bonding, improving tensile strength and preventing breakage. Its porous structure also helps absorb mid-to-low frequency sound waves, compensating for the sound insulation shortcomings of traditional substrates. Furthermore, it uses industrial biomass waste as raw material, replacing some petroleum-based PVC and reducing the material's dependence on non-renewable resources. Modified montmorillonite, after CTAB intercalation modification, exhibits better dispersibility. The organic-inorganic composite damping agent formed with butyl rubber significantly increases the material's damping factor, strengthening its ability to absorb broadband sound waves, particularly improving mid-to-low frequency sound insulation. Inorganic montmorillonite also enhances the material's structural stability and weather resistance (anti-aging, resistance to heat and oxygen degradation), while synergistically maintaining a balance of mechanical properties with the organic phase. The surface activity of modified corn stalks is enhanced after alkali treatment, which, in conjunction with modified hollow glass microspheres, constructs a rational porous structure. This structure improves sound insulation through sound wave scattering and adsorption while avoiding the decrease in tensile strength caused by excessive porosity. Furthermore, its recycling as agricultural waste further reduces the environmental impact of the material. Combined with modified lignin, it promotes the green and environmentally friendly transformation of materials, mitigating the environmental risks of traditional materials and aligning with the needs of green development. The synergistic effect of these three elements achieves a balance between mechanical properties, sound insulation, and weather resistance, while maximizing the material's environmental attributes.

[0080] In summary, the sound insulation material composition produced by this invention combines wide-band sound insulation, excellent mechanical properties, and environmental friendliness.

[0081] The above are merely specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions, or modifications made based on the present invention to solve essentially the same technical problems and achieve essentially the same technical effects are all covered within the protection scope of the present invention.

Claims

1. A sound insulating material composition, characterized by, The composite base material is prepared by mixing polyvinyl chloride and acetylated modified lignin at a mass ratio of 2-3:

1. The organic-inorganic composite damping agent is a compound of butyl rubber and CTAB intercalated modified montmorillonite, and the mass ratio of the two is 3-5:

1. The pore adjusting agent is prepared by mixing modified hollow glass microbeads and modified corn stalks at a mass ratio of 1-2:

1. The preparation method of the modified hollow glass microbeads is as follows: prepare hollow glass microbeads with a particle size of 50-100 μm; add 0.5-2% of silane coupling agent KH-550 to an ethanol solution with a mass concentration of 95%, wherein the amount of the ethanol solution with a mass concentration of 95% is 15-20 times the mass of the hollow glass microbeads, then adjust the pH of the solution to 4-5.5 using glacial acetic acid, stir at room temperature for 20-30 min, then add the hollow glass microbeads, stir at a speed of 100-300 rpm in a constant-temperature water bath at 60-80°C for 1.5-3 h, after the reaction is completed, perform suction filtration using a Buchner funnel, wash the filter cake with anhydrous ethanol for 2-3 times, then place the filter cake in an oven and dry at 80-100°C for 3-4 h, and after drying, gently stir to obtain the surface-modified hollow glass microbeads. The preparation method of the modified corn stalks is as follows: grind the dried corn stalks and pass them through an 80-mesh sieve, mix the ground corn stalks with a 5% sodium hydroxide aqueous solution at a mass ratio of 1:15-20, and stir the mixture in a constant-temperature water bath at 70°C at a speed of 200 rpm for 2 h. After the reaction is completed, perform suction filtration using a Buchner funnel to obtain a filter cake, wash the filter cake with deionized water for 2-3 times, place the washed filter cake in a forced air drying oven and dry at 70-75°C for 24 h until the weight is constant, grind the dried filter cake and pass it through a 100-mesh sieve to obtain the modified corn stalks. The preparation method of the acetylated modified lignin is as follows: mix industrial lignin with deionized water at a mass ratio of 1:10, stir for 30 min, perform suction filtration to obtain a filter cake, wash the filter cake with deionized water for 2-3 times, then place the filter cake in a vacuum drying oven at 60-80°C and dry for 8-12 h, grind and pass through a 100-120 mesh sieve to obtain purified lignin; mix the purified lignin with acetic acid at a mass ratio of 1:5-8, stir uniformly, then add acetic anhydride dropwise, stir at a speed of 300-500 rpm at 60-80°C for 2-4 h; after the reaction is completed, pour the reaction solution into 10 times the volume of ice water, stand for 25-30 min, then filter to collect the precipitate, wash the precipitate with deionized water for 2-3 times, then wash the precipitate with a 50% ethanol solution for 1-2 times, after the washing is completed, place the precipitate in a vacuum drying oven at 60-70°C and dry for 6-10 h, grind and pass through a 100-mesh sieve to obtain the acetylated modified lignin.

2. A soundproofing material composition according to claim 1, wherein ​ 3. A soundproofing material composition according to claim 2, wherein The mass ratio of the acetic anhydride to the purified lignin is 1.5-2.5:

1.

4. A soundproofing material composition according to claim 1, wherein The preparation method of the CTAB intercalation modified montmorillonite is as follows: sodium-based montmorillonite and deionized water are mixed at a mass ratio of 1:10-15, stirred at 60-70 DEG C at a rotation speed of 300-500 rpm for 1 h to form a uniform suspension; The suspension is washed with deionized water for 2-3 times, the washed montmorillonite suspension is centrifuged at 8000 rpm for 10-15 min, and the lower solid is collected to obtain purified montmorillonite; the purified montmorillonite and deionized water are mixed at a mass ratio of 1:10-12, stirred at 70-80 DEG C for 30-35 min to form a uniformly dispersed montmorillonite suspension; a CTAB solution with a mass concentration of 1-1.5% is slowly added to the montmorillonite suspension, the temperature is kept at 70-80 DEG C, and the reaction is carried out at a stirring speed of 400-600 rpm for 2-3 h; after the reaction, the mixture is centrifuged at 8000 rpm for 10 min, and the lower solid is collected; then the solid is washed with deionized water for 2-3 times, dried in a vacuum drying oven at 60-70 DEG C for 10-12 h, ground and sieved through a 200-mesh screen to obtain the CTAB intercalation modified montmorillonite.

5. A soundproofing material composition according to claim 4, wherein The mass ratio of the CTAB solution with a mass concentration of 1-1.5% to the purified montmorillonite is 0.2-0.3:

1.

6. A soundproofing material composition according to claim 1, wherein The compatilizer is maleic anhydride grafted polypropylene.

7. A soundproofing material composition according to claim 1, wherein The lubricant is a compound of stearic acid and zinc stearate at a mass ratio of 1:

1.

8. The acoustical material composition of claim 1 wherein, The antioxidant is a compound of antioxidant 1010 and antioxidant 168 at a mass ratio of 1:0.5.

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