Preparation method of high-performance sound insulation material based on waste biomass and organic modifier

Abstract

The invention belongs to the field of renewable resource environment-friendly materials, and particularly discloses a preparation method of a high-performance sound insulation material based on waste biomass and an organic modifier, which comprises the following steps: classifying, cleaning and crushing the waste biomass (such as plant fiber, wood, straw and the like); synthesizing an organic modifier containing a specific group; mixing the waste biomass particles, the organic modifier, the inorganic sound insulation filler, the plasticizer and the lubricant in proportion, and uniformly stirring in a high-speed mixer; and finally, extruding and molding by a double-screw extruder, cooling and pelletizing to obtain a finished product. According to the method, by means of the synergistic effect of the modifier and the biomass, the sound insulation, mechanical and processing properties are improved, waste biomass resource utilization is achieved, the defects of traditional sound insulation materials are effectively overcome, and the method is suitable for noise reduction requirements in multiple fields.

Description

Technical Field

[0001] The present invention relates to the field of preparation of environmentally friendly materials, and in particular to a method for preparing a high-performance sound insulation material based on waste biomass and an organic modifier. Background Art

[0002] At a time when the world is advocating sustainable development and circular economy, the output of waste biomass is increasing day by day with the vigorous development of agriculture, forestry and food processing industries. A large amount of biomass waste such as crop straw, waste wood, and fruit shells are piled up. If traditional incineration methods are used, not only will pollutants such as carbon dioxide, carbon monoxide, nitrogen oxides and particulate matter be released during the combustion process, aggravating air pollution, affecting air quality, and endangering human health, but also causing the rich organic resources contained in biomass to be wasted in vain; landfill disposal also has many disadvantages, occupying a large amount of land resources, and in the anaerobic environment of the landfill, biomass decomposes slowly, and may seep out organic acids and other substances, polluting the soil and surrounding water bodies, and destroying the ecological balance.

[0003] Looking at the current situation of the sound insulation material market, it is difficult for existing products to take into account multiple performance requirements. Traditional organic sound insulation materials such as polyvinyl chloride foam and phenolic foam, although they are easy to process and have good initial sound insulation effects, have poor long-term stability and are easily affected by environmental factors such as temperature and humidity, resulting in aging and deformation problems, leading to a decline in sound insulation performance. In addition, some materials have poor flame retardancy, and fire hazards cannot be ignored; inorganic sound insulation materials such as glass wool and asbestos, although they have high temperature resistance and flame retardancy, are brittle and hard, with poor flexibility. They are easy to break and shatter during installation, transportation and use, generating dust pollution. At the same time, they have poor low-frequency noise blocking effects and are difficult to cope with complex noise environments such as low-frequency vibrations of large equipment in factories and low-frequency tire noise on traffic arteries. Waste biomass is rich in natural polymer components such as cellulose, lignin, and hemicellulose. It has the advantages of wide sources, renewable, and low cost. After reasonable modification and processing, it is expected to become a high-quality raw material for new high-performance sound insulation materials, filling the market gap and conforming to the concept of green development. Summary of the invention

[0004] The present invention provides a method for preparing a high-performance sound insulation material based on waste biomass and an organic modifier, comprising the following steps: S1 waste biomass pretreatment step: collect crop straw, waste wood, fruit shell waste biomass raw materials, remove stones, soil, metal impurities through manual or mechanical sorting, break them into 0.5-2cm fragments, place them in a special cooking equipment containing 2%-5% dilute alkali solution, cook at 100-120℃ for 2-4 hours, rinse repeatedly with clean water until neutral, dry at 60-80℃ to constant weight, grind into 0.1-0.5mm biomass powder for standby use; S2 organic modifier synthesis step: in a reactor equipped with temperature control, stirring, condensation reflux and inert gas protection system, 3-amino-4-hydroxybenzoic acid and ethyl chloroacetate are added in a molar ratio of 1:1.3, and triethylamine is added as a catalyst which is 3% of the mass of 3-amino-4-hydroxybenzoic acid, and the temperature is raised to 55-65°C under nitrogen atmosphere and stirred for 8-12 hours to complete the esterification reaction to obtain an intermediate product esterified product, and then the esterified product and allyl alcohol are mixed in a dichloromethane solvent accounting for 40% of the total mass of the raw materials in a molar ratio of 1:1.1, and anhydrous sodium carbonate which is 1.2 times the mass of the esterified product is added as an acid binding agent, and allyl alcohol is added dropwise in an ice bath at 0-3°C, and then the temperature is raised to 45-55°C and stirred for 10-14 hours, and the impurities are filtered out, and the deionized water and ethanol are washed alternately, and the organic modifier 3-amino-4-hydroxybenzoic acid allyl ester with a purity of more than 90% is obtained. S3 material mixing and molding step: according to the mass proportions, 40-60 parts of the waste biomass powder, 5-10 parts of the organic modifier, 8-15 parts of the inorganic reinforcing filler, 2-4 parts of the plasticizer and 0.5-1.5 parts of the lubricant are added into a high-speed mixer in sequence, stirred at 90-110°C and 500-800 rpm for 30-40 minutes to form a premix, the premix is ​​input into a twin-screw extruder, the screw speed is 150-200 rpm, the temperature of each section of the extruder from the feed port to the die is set to 160-180°C, 180-200°C, 200-220°C and 220-240°C in sequence, and high-performance sound insulation material particles are obtained through extrusion, cooling and pelletizing.

[0005] Furthermore, the waste biomass powder accounts for 40-60 parts by mass in the finished product, and the impurity content is less than 0.3% after being removed by a combination of screening, air separation and magnetic separation.

[0006] Furthermore, the organic modifier accounts for 5-10 parts by mass of the finished product, and an antioxidant is added in an amount of 0.5%-1% of the total mass of the raw materials during the synthesis process to prevent oxidation and deterioration.

[0007] Furthermore, the inorganic reinforcing filler accounts for 8-15 parts by mass of the finished product, and the inorganic reinforcing filler is one or more combinations of expanded vermiculite and mica powder.

[0008] Furthermore, the plasticizer is dibutyl phthalate, accounting for 2-4 parts by mass of the finished product; the lubricant is magnesium stearate, accounting for 0.5-1.5 parts by mass of the finished product.

[0009] On the other hand, the present invention also provides a high-performance sound insulation material obtained by the preparation method, which comprises, by mass, 40-60 parts of waste biomass powder, 5-10 parts of organic modifier, 8-15 parts of inorganic reinforcing filler, 2-4 parts of plasticizer, and 0.5-1.5 parts of lubricant. The material has the performance indicators of sound insulation performance of an average low-frequency sound insulation of not less than 28dB at 100-1000Hz, an average high-frequency sound insulation of not less than 36dB at 1000-5000Hz, a tensile strength of not less than 14MPa, an elongation at break of not less than 160%, and a bending strength of not less than 18MPa.

[0010] Beneficial technical effects: A large amount of waste plant fiber, wood, crop straw, etc. can be utilized as resources, reducing environmental pollution caused by landfill or incineration of waste, reducing carbon emissions, and conforming to the concept of green circular economy. From the perspective of performance, the sound insulation performance is excellent. Organic modifiers rely on the synergistic effect of hydroxyl, methoxy, amino, and nitro groups to strengthen the combination with waste biomass, optimize the internal structure, and make sound waves reflect and scatter multiple times. The sound insulation volume in the 800-1000Hz frequency band is significantly improved, effectively blocking the propagation of noise. Excellent mechanical properties, amino covalent bonds and hydroxyl hydrogen bonds enhance the strength and toughness of the material, and the tensile strength and impact strength are improved. The product's ability to resist external impact becomes stronger and its durability is improved. Good processing performance, methoxy groups give flexibility and steric hindrance, improve material fluidity, cooperate with precise process parameters, the material is fully filled into the mold, and the product appearance is smooth and flawless, which is conducive to large-scale production. In terms of application expansion, a variety of sound insulation products are made to meet the noise reduction needs of construction, transportation, and industrial equipment, reduce sound insulation costs, and improve the quality of industry sound insulation materials. The market prospects are broad and help sustainable development. DETAILED DESCRIPTION

[0011] Example 1

[0012] Widely collect waste biomass raw materials such as crop straw (such as wheat, rice, corn straw, etc.), waste wood (such as old furniture, construction waste wood, etc.), fruit shells (such as peanut shells, walnut shells, etc.), and remove foreign matter such as stones, soil, and metal impurities mixed in them through manual or mechanical sorting. Use a crusher to break the screened biomass into pieces of about 0.5 cm in size, then place it in a special cooking equipment, add an appropriate amount of dilute alkali solution (sodium hydroxide or potassium hydroxide solution, concentration 2%), and cook it at 100°C for 2 hours to remove impurities such as lignin and pectin, soften the biomass fiber structure, and enhance its subsequent processing performance. After cooking, rinse repeatedly with a large amount of clean water until neutral, put it in a drying oven and dry it at 60°C to constant weight, and finally process it into a biomass powder with a particle size of 0.1mm for standby use.

[0013] The synthesis of organic modifiers was carried out in a reactor equipped with precise temperature control, efficient stirring, condensation reflux and inert gas protection systems. 3-amino-4-hydroxybenzoic acid, ethyl chloroacetate, allyl alcohol, triethylamine, anhydrous sodium carbonate and the like were used as raw materials. First, an esterification reaction was carried out. The raw materials were accurately weighed according to the molar ratio of 3-amino-4-hydroxybenzoic acid to ethyl chloroacetate 1:1.3 and put into the reactor. Triethylamine was added as a catalyst (the amount was 3% of the mass of 3-amino-4-hydroxybenzoic acid). Under a nitrogen atmosphere, the temperature was slowly raised to 55°C, and the reaction was stirred for 8 hours to obtain an intermediate product esterification. Then, a substitution reaction was carried out. The above esterification and allyl alcohol were mixed in an appropriate amount of dichloromethane solvent (the amount of solvent was 40% of the total mass of the raw materials) at a molar ratio of 1:1.1, and an acid-binding agent anhydrous sodium carbonate (the amount was 1.2 times the mass of the esterification) was added. Allyl alcohol was slowly added dropwise under an ice bath at 0°C. After the addition was completed, the temperature was raised to 45°C, and the reaction was continued for 10 hours. After the reaction is completed, the generated salt impurities are removed by filtration, and the residual reactants are removed by alternating washing with deionized water and ethanol for multiple times. Finally, the product is dried in a vacuum drying oven to obtain an organic modifier 3-amino-4-hydroxybenzoic acid propylene ester with a purity of more than 90%.

[0014] According to the mass percentage, accurately weigh 40 parts of pretreated waste biomass powder, 5 parts of synthetic organic modifier, 8 parts of inorganic reinforcing filler (such as expanded vermiculite, mica powder, etc.), 2 parts of plasticizer (such as dibutyl phthalate), and 0.5 parts of lubricant (such as magnesium stearate). Add the above raw materials to the high-speed mixer in turn, set the mixer temperature to 90°C, the stirring speed to 500 rpm, and continue stirring for 30 minutes until the material has uniform color and texture to form a premix. The premix is ​​then conveyed to the twin-screw extruder, the screw speed is controlled at 150 rpm, and the temperature of each section of the extruder is set to 160°C, 180°C, 200°C, and 220°C from the feed port to the head. The material is extruded, cooled, and pelletized to make high-performance sound insulation material particles. These particles can be further processed into various sound insulation products such as sound insulation panels and sound insulation pipes through molding processes such as injection molding and compression molding.

[0015] Furthermore, waste biomass powder accounts for 40 parts by mass in the finished product. The sources can be diversified and the impurity content should be guaranteed to be less than 0.3% (mass percentage). Efficient impurity removal can be achieved through composite means such as screening, air separation and magnetic separation.

[0016] Furthermore, the organic modifier accounts for 5 parts by mass of the finished product. During the synthesis process, an appropriate amount of antioxidant (such as ascorbic acid, tocopherol, etc., with an amount of 0.5% of the total mass of the raw materials) can be added as needed to prevent oxidation and deterioration during the reaction process and storage of the finished product.

[0017] Furthermore, the inorganic reinforcing fillers account for 8 parts by mass of the finished product. Single or multiple fillers can be flexibly selected according to the required sound insulation and mechanical properties. For example, if the emphasis is on sound insulation, the proportion of expanded vermiculite can be increased, and if strength is emphasized, the amount of mica powder can be increased.

[0018] Furthermore, the high-performance sound insulation material contains, by mass, 40 parts of waste biomass powder, 5 parts of organic modifier, 8 parts of inorganic reinforcing filler, 2 parts of plasticizer, and 0.5 parts of lubricant.

[0019] The organic modifier used plays a key role. The amino group (-NH2) in the molecule is highly reactive and can undergo covalent bonding reactions with the abundant hydroxyl (-OH), carboxyl (-COOH) and other functional groups on the surface of waste biomass, acting like a "chemical anchor point" to tightly link the modifier and the biomass matrix, greatly enhancing the interfacial bonding force, effectively preventing debonding and stratification during subsequent processing and use, and stabilizing the material structure; the hydroxyl (-OH) uses hydrogen bonding to enhance the affinity with biomass and other components, optimize the internal microstructure, and improve the flexibility and stability of the material; the acrylate group gives the molecular chain flexibility and cross-linking properties. When impacted by sound waves or external forces, the flexible chain segments can deform freely, buffer energy, and inhibit the generation of cracks. The cross-linked structure enhances the overall strength and ensures the mechanical properties of the material. The scientific formula has significant synergistic effects. Waste biomass powder lays the basic framework, giving the material the advantages of being renewable and lightweight. Inorganic reinforcing fillers reflect and scatter sound waves with their unique flaky and layered structures (such as expanded vermiculite expands when heated to form closed pores, and mica powder is stacked layer by layer), enhancing the sound insulation effect and improving mechanical strength. Plasticizers improve the processing fluidity and flexibility of materials, and lubricants reduce the friction coefficient to ensure smooth processing. The various components complement each other and achieve a delicate balance between sound insulation, mechanics, and processing performance. The comprehensive performance far exceeds that of traditional biomass-based sound insulation materials. The entire process of the adaptation process is precisely controlled, from the "removal of coarse and fine" of biomass pretreatment, the "fine grinding" of modifier synthesis, to the "uniform blending" of material mixing, and the "striking while the iron is hot" of extrusion molding. Each link is closely connected to fully tap the potential of the material. The sound insulation material produced is highly efficient in sound insulation, mechanically stable, and reliable in quality, which is suitable for multiple application scenarios, opening up a new path for the resource utilization of waste biomass and the innovation of sound insulation materials, and expanding broad market prospects.

[0020] Example 2

[0021] Collect wheat straw and waste pine wood boards and pretreat them to make waste biomass powder with a particle size of 0.1 mm, and weigh 50 parts; synthesize the organic modifier 3-amino-4-hydroxybenzoic acid propylene ester according to the process, and weigh 8 parts; prepare 10 parts of expanded vermiculite (particle size 0.2 mm), 3 parts of dibutyl phthalate, and 1 part of magnesium stearate.

[0022] Waste biomass was operated according to the above pretreatment process. When the organic modifier was synthesized, the esterification reaction was heated to 60°C and reacted for 10 hours. The substitution reaction was heated to 50°C after ice bath addition and reacted for 12 hours. In the material mixing stage, the high-speed mixer was set at 100°C and 600 rpm. The basic material was mixed for 35 minutes, and then the material was input into the twin-screw extruder with a screw speed of 180 rpm. The temperature of each section was set to 170°C, 190°C, 210°C, and 230°C in turn. The finished product was obtained after extrusion, cooling, and pelletizing.

[0023] The sound insulation performance was tested by building a test platform according to ASTME90 standard, and the material of the present invention, commercially available common biomass-based sound insulation materials, and traditional phenolic foam sound insulation materials were prepared for testing. The material of the present invention has an average low-frequency sound insulation of 30dB at 100-1000Hz and an average high-frequency sound insulation of 38dB at 1000-5000Hz; the commercially available common biomass-based sound insulation materials have a low frequency of 22dB and a high frequency of 30dB; the traditional phenolic foam sound insulation materials have a low frequency of 18dB and a high frequency of 26dB, and the sound insulation advantage of the present invention is outstanding.

[0024] Mechanical properties were measured by a universal material testing machine to measure tensile strength and elongation at break, and by a bending test to measure bending strength. The tensile strength of the present invention is 16MPa, the elongation at break is 180%, and the bending strength is 20MPa; the tensile strength of common unmodified biomass sound insulation materials on the market is 10MPa, the elongation at break is 120%, and the bending strength is 14MPa. The mechanical properties of the present invention are significantly improved, and it is suitable for complex working conditions.

[0025] Example 3

[0026] Waste biomass powder is made of corn stalks and peanut shells mixed raw materials with a particle size of 0.5mm after treatment, and the dosage is increased to 60 parts, the corresponding organic modifier synthesis amount is adjusted to 10 parts, expanded vermiculite (particle size 0.6mm) 15 parts, dibutyl phthalate 4 parts, magnesium stearate 1.5 parts. Pretreatment of biomass powder by microwave irradiation (power 800W, time 5 minutes); organic modifier synthesis, esterification reaction molar ratio adjusted to 1:1.4, reaction temperature increased by 65℃, time extended to 12 hours, substitution reaction acid binding agent dosage 1.3 times, reaction temperature 55℃, time 14 hours; material mixing stage, high-speed mixer temperature 110℃, speed 800 rpm, mixing for 40 minutes, twin-screw extruder screw speed 200 rpm, each section temperature is 180℃, 200℃, 220℃, 240℃.

[0027] After testing, the average low-frequency sound insulation performance reached 33dB, and the high-frequency sound insulation increased to 41dB. The mechanical properties had a tensile strength of 20MPa, an elongation at break of 220%, and a bending strength of 24MPa. Compared with Example 1 and commercially available products, the comprehensive performance was better, which verified that the process adjustment was effective and highlighted the potential advantages of the invention.

[0028] Example 4

[0029] 40 parts of waste biomass powder with a particle size of 0.1 mm was prepared from discarded poplar and walnut shells; 5 parts of 3-amino-4-hydroxybenzoic acid propylene ester, a synthetic organic modifier; 8 parts of mica powder (particle size 0.1 mm), 2 parts of dibutyl phthalate, and 0.5 parts of magnesium stearate were selected.

[0030] Strictly follow the established process, the organic modifier esterification reaction is 55℃, the reaction is 8 hours, the substitution reaction is added dropwise in an ice bath and the temperature is raised to 45℃, and the reaction is 10 hours. The high-speed mixer is 90℃, the speed is 500 rpm, and after mixing for 30 minutes, it is put into the twin-screw extruder (screw speed is 150 rpm, and the temperature of each section is 160℃, 180℃, 200℃, and 220℃), extruded, cooled, and pelletized to obtain the finished product.

[0031] Performance testing and comparison

[0032] The sound insulation performance is as follows: the average low-frequency sound insulation of 100-1000Hz is 28dB, the average high-frequency sound insulation of 1000-5000Hz is 36dB, the mechanical performance is as follows: the tensile strength is 14MPa, the elongation at break is 160%, and the bending strength is 18MPa. Compared with similar products on the market, it still has advantages, demonstrating the universality and stability of the invention.

[0033] Example 5 The prepared high-performance sound insulation material is mainly composed of the following components (the content of each component is expressed in mass ratio): Waste biomass matrix: 35 samples, selected from various types of waste biomass, including but not limited to crop straw, rice husks, wood chips, bamboo chips, etc. These waste biomass need to be pre-treated and used as the main matrix component of the sound insulation material to provide basic structural support for the material.

[0034] New organic modifier: 12 parts, chemical name is 6-(3-hydroxy-4-methoxybutyl)-2-amino-4-nitrobenzoic acid ethyl ester). Composite sound insulation filler: 18 parts, composed of inorganic sound insulation filler and organic sound insulation filler. Inorganic sound insulation filler can be selected from expanded perlite powder, nano-silicon dioxide, etc.; organic sound insulation filler can be selected from waste rubber powder, waste plastic fiber, etc. This composite structure filler can more effectively enhance the sound insulation performance of the material. Plasticizer: 2-4 parts, such as dioctyl phthalate, etc., used to improve the flexibility of the material and make it easier to process and shape. Lubricant: 0.5 parts, such as calcium stearate, helps to reduce the friction of the material during processing and improve processing efficiency.

[0035] Synthesis method of novel organic modifier, raw material preparation: prepare the following raw materials, 2-amino-4-nitrobenzoic acid, 3-hydroxy-4-methoxybutanol, ethyl chloroformate, triethylamine, sodium carbonate, dichloromethane, etc., to ensure that each raw material meets the specified purity requirements to ensure the smooth progress of the synthesis reaction. Step 1: Esterification reaction: In the reactor, 2-amino-4-nitrobenzoic acid and ethyl chloroformate are added in a molar ratio of 1:1.25, and an appropriate amount of triethylamine is added as a catalyst (the amount of triethylamine is 4.5% of the mass of 2-amino-4-nitrobenzoic acid). Under nitrogen protection, the temperature is raised to 52 degrees Celsius for esterification reaction, and the reaction time is set to 6.5 hours. Through this reaction, an ester group is introduced at the carboxyl position of 2-amino-4-nitrobenzoic acid to obtain intermediate product A. Step 2: Substitution reaction: In another reaction device, the intermediate product A and 3-hydroxy-4-methoxybutanol are mixed in a solvent of dichloromethane, and an acid-binding agent sodium carbonate is added (the amount of sodium carbonate is 1.25 times the mass of the intermediate product A). The substitution reaction is carried out under ice bath conditions (the temperature is controlled at 0-3 degrees Celsius), and the reaction time is 8.5 hours. In this reaction, the hydroxyl group in 3-hydroxy-4-methoxybutanol replaces part of the groups on the intermediate product A to obtain a new organic modifier. Step 3: Purification treatment: After the reaction is completed, the solid impurities such as salts generated by the reaction are removed by filtration, and then washed with deionized water and an organic solvent (such as ethanol) for multiple times to remove residual impurities and unreacted raw materials. Finally, the washed product is dried in a vacuum drying oven to obtain a pure new organic modifier.

[0036] Synergistic mechanism of composite sound insulation filler: The composite sound insulation filler used in the present invention is composed of inorganic sound insulation filler and organic sound insulation filler. Inorganic sound insulation fillers such as expanded perlite powder, nano-silicon dioxide, etc. have high density and rigidity, and can effectively reflect and scatter sound waves, reducing the propagation path of sound waves in the material. Organic sound insulation fillers such as waste rubber powder and waste plastic fibers have good flexibility and damping characteristics. Under the action of sound waves, they can absorb sound wave energy through their own deformation and vibration, and convert it into other forms of energy such as heat energy and consume it. The composite structure formed by the combination of the two ensures that when sound waves propagate in the material, they will encounter reflection and scattering obstacles of inorganic fillers, and will also be absorbed by organic fillers, thereby greatly improving the sound insulation performance of the material.

[0037] Overall improvement effect on sound insulation materials: By adding this composite sound insulation filler, compared with traditional sound insulation materials that only use a single type of filler, under the same thickness and conditions, the sound insulation material prepared by the present invention can significantly improve the sound insulation volume and better meet the strict requirements for sound insulation effects in different environments.

[0038] Special group effects of new organic modifiers, amino (-NH2) group: The amino group in the compound has strong reactivity and can react chemically with certain functional groups (such as carboxyl, aldehyde, etc.) on the surface of the waste biomass matrix to form a covalent bond. The formation of this covalent bond greatly enhances the interfacial bonding force between the modifier and the waste biomass, allowing the modifier to firmly adhere to the surface of the waste biomass and prevent the modifier from falling off during subsequent processing or use. At the same time, this also helps to improve the mechanical properties of the sound insulation material, such as tensile strength and impact strength.

[0039] Nitro (-NO2) group: Nitro has a strong electron-withdrawing effect, which can change the electron cloud distribution of the modifier molecule, thereby affecting its interaction with the waste biomass matrix and other additives (such as composite sound insulation fillers, plasticizers, etc.). In sound insulation materials, the electron-withdrawing effect of nitro can enhance the electrostatic attraction between the modifier and the matrix, and promote the uniform dispersion of the modifier in the sound insulation material. At the same time, the presence of nitro helps to improve the thermal stability of the sound insulation material, inhibit the excessive movement and degradation reaction of the material at high temperature, so that the sound insulation material can maintain good performance under different environmental conditions. Hydroxyl (-OH) group: Hydroxyl has a unique role in the present invention. On the one hand, hydroxyl and oxygen-containing functional groups (such as hydroxyl, carboxyl, etc.) on the surface of the waste biomass matrix attract each other through hydrogen bonding, which enhances the affinity between the modifier and the matrix, so that the modifier can be more evenly distributed on the surface of the matrix; on the other hand, when the material is impacted by sound waves, the hydrogen bonds between the hydroxyl groups can change dynamically, play a certain buffering role, absorb and disperse the sound wave energy, and help improve the sound insulation performance of the sound insulation material. Methoxy (-OCH3) group: The presence of methoxy increases the flexibility and steric hindrance effect of the compound. In terms of flexibility, it enables the modifier molecules to better adapt to the morphological changes of biomass particles when interacting with waste biomass, thereby forming a flexible connection network inside the material, which helps to improve the flexibility and processing performance of the sound insulation material (such as improving fluidity). The steric hindrance effect can prevent excessive aggregation between modifier molecules, ensure their uniform dispersion in the matrix of sound insulation materials, and thus improve the overall performance of sound insulation materials. Comprehensive impact on sound insulation materials: Through the synergistic effect of the above groups, the new organic modifier can improve the performance of sound insulation materials from multiple aspects. In terms of sound insulation performance, on the one hand, the good combination of the modifier and the waste biomass matrix helps to form a tighter structure, reduce the propagation path of sound waves in the material, and make the sound waves constantly reflect and scatter inside the material, thereby improving the sound insulation effect of the sound insulation material; on the other hand, factors such as the hydrogen bond buffering effect of the hydroxyl group and the electron-withdrawing effect of the nitro group may affect the sound wave propagation characteristics inside the material, further enhancing the sound insulation effect. In terms of mechanical properties, the covalent bond formed by the amino group and the flexible connection network of the methoxy group jointly improve the tensile strength and toughness of the sound insulation material, enabling it to withstand certain external forces without being easily damaged. In terms of processing performance, the flexibility and steric hindrance effect of the methoxy group improve the fluidity of the sound insulation material, making it easier to operate during the molding process, thereby improving the processing quality and production efficiency of the sound insulation material.

[0040] Step 1: Pretreatment of waste biomass: Collect various types of waste biomass and classify them first to separate different types of biomass for subsequent treatment. Then clean them to remove dirt, labels and other impurities on the surface. Then crush them into particles with a particle size within 0.5mm for later use.

[0041] Step 2: Raw material mixing: Add the pre-treated waste biomass matrix, the synthesized new organic modifier, the composite sound insulation filler, the plasticizer and the lubricant into the high-speed mixer according to the above mass ratio. Mix for 20-30 minutes at a temperature of 80 degrees Celsius and a stirring speed of 400 rpm to fully mix the components.

[0042] Step 3: Molding: Add the mixed materials to a twin-screw extruder for extrusion molding. The screw speed of the extruder can be adjusted between 150 rpm, and the extrusion temperature can be adjusted from the feed port to the die head between 160 degrees Celsius, 180 degrees Celsius, 200 degrees Celsius, 220 degrees Celsius, and 200 degrees Celsius. According to the melt viscosity and molding requirements of the material, the extruder parameters are reasonably adjusted to ensure the extrusion molding quality and production efficiency of the material. The extruded material is cooled and pelletized to obtain high-performance sound insulation material particles prepared based on waste biomass and organic modifiers. These particles can be further used to manufacture various sound insulation products, such as sound insulation panels, sound insulation pipes, sound insulation injection molding products, etc. The new organic modifier is used to modify the waste biomass-based material, and combined with the unique composite sound insulation filler structure, through its unique molecular structure and mechanism of action, it effectively overcomes the shortcomings of traditional sound insulation materials in sound insulation performance, mechanical properties and processing performance. In terms of sound insulation performance, the sound insulation effect of sound insulation materials is significantly improved, which can better block the propagation of sound waves and meet higher sound insulation requirements; in terms of mechanical properties, the tensile strength, impact strength and other indicators of sound insulation materials are enhanced, so that they can withstand external impact without being easily damaged; in terms of processing performance, the fluidity of sound insulation materials is improved, and the quality and efficiency of molding processing are improved. At the same time, by recycling and reusing waste biomass, resource waste and environmental pollution are reduced, which is in line with the concept of sustainable development, provides an effective solution for the treatment of waste biomass, and expands the application possibilities of sound insulation materials in more fields.

[0043] Example 6 Waste biomass matrix: Collect crop straw, and after pretreatment processes such as classification, cleaning, and crushing, obtain a waste biomass matrix with a particle size between 0.5 mm, and prepare 100 kg. New organic modifier: Prepare according to the above synthesis method to obtain 15 kg. Composite sound insulation filler: Select expanded perlite micropowder as an inorganic sound insulation filler 12 kg and waste rubber powder as an organic sound insulation filler 6 kg to form a composite sound insulation filler, and prepare 18 kg. Plasticizer: Select dioctyl phthalate, the amount is 3 kg. Lubricant: Select calcium stearate, the amount is 1 kg.

[0044] Preparation process, raw material mixing: 100kg pre-treated waste biomass matrix, 15kg new organic modifier, 18kg composite sound insulation filler, 3kg dioctyl phthalate and 1kg calcium stearate are added to a high-speed mixer. Mix for 25 minutes at a temperature of 90 degrees Celsius and a stirring speed of 500 rpm to fully mix the components.

[0045] Molding: The mixed materials are added to a twin-screw extruder for extrusion molding. The screw speed of the extruder is 170 rpm, and the extrusion temperature is set to 165 degrees Celsius, 185 degrees Celsius, 205 degrees Celsius, 225 degrees Celsius, and 205 degrees Celsius from the feed port to the die head. The extruded materials are cooled and pelletized to obtain high-performance sound insulation material particles prepared based on waste biomass and organic modifiers.

[0046] Performance test and comparative test, sound insulation performance test: the sound insulation performance test of the prepared high-performance sound insulation material particles was carried out by the standing wave tube method. The results show that at a frequency of 1000Hz, the sound insulation volume increased by 25dB, indicating that the sound insulation effect was significantly improved. Comparative test: a common sound insulation material based on crop straw on the market that has not been treated with the modifier of the present invention was selected for the same sound insulation performance test. The results show that the sound insulation volume of the product at a frequency of 1000Hz is low, and the sound insulation effect is relatively poor. The high-performance sound insulation material prepared by the present invention is significantly superior to the common unmodified products on the market in terms of sound insulation performance. Mechanical property test: The tensile strength and impact strength test of the prepared high-performance sound insulation material particles were carried out by a universal material testing machine. The results show that the tensile strength reaches 28MPa and the impact strength reaches 12kJ / m². Comparative test: a common sound insulation material based on crop straw on the market that has not been treated with the modifier of the present invention was selected for the same mechanical property test. The results show that the tensile strength of the product is 20MPa and the impact strength is 8kJ / m². The high-performance sound insulation material prepared by the present invention is significantly superior to the common unmodified products on the market in terms of mechanical properties. Processing performance test: observe the mold filling during the molding process and the appearance quality of the product. The results show that the high-performance sound insulation material prepared by the present invention is completely molded in the twin-screw extruder, and the product appearance is smooth and has no obvious defects. Comparative test: A common crop straw-based sound insulation material on the market that has not been treated with the modifier of the present invention was selected for the same processing performance test. The results show that the product has incomplete mold filling during the molding process and the product appearance has defects. The high-performance sound insulation material prepared by the present invention is significantly superior to the common unmodified products on the market in terms of processing performance.

[0047] Example 7 Waste biomass matrix: collect sawdust, and after pretreatment processes such as classification, cleaning, and crushing, obtain a waste biomass matrix with a particle size between 1mm, and prepare 80kg. New organic modifier: Prepare according to the above synthesis method to obtain 12kg. Composite sound insulation filler: Select nano-silicon dioxide as an inorganic sound insulation filler 10kg and waste plastic fiber as an organic sound insulation filler 8kg to form a composite sound insulation filler, and prepare 18kg. Plasticizer: Select dioctyl phthalate, the amount is 2.5kg. Lubricant: Select calcium stearate, the amount is 0.8kg.

[0048] Preparation process, step 1: raw material mixing: add 80kg of pretreated waste biomass matrix, 12kg of new organic modifier, 18kg of composite sound insulation filler, 2.5kg of dioctyl phthalate and 0.8kg of calcium stearate into a high-speed mixer. Mix for 22 minutes at a temperature of 85 degrees Celsius and a stirring speed of 450 rpm to fully mix the components. Step 2: Molding: Add the mixed materials to a twin-screw extruder for extrusion molding. The screw speed of the extruder is 160 rpm, which should be "the screw speed of the extruder is 160 rpm, and the extrusion temperature is set to 160 degrees Celsius, 180 degrees Celsius, 200 degrees Celsius, 220 degrees Celsius, and 200 degrees Celsius from the feed port to the head. Step 3: Result acquisition: The extruded material is cooled and pelletized to obtain high-performance sound insulation material particles prepared based on waste biomass and organic modifiers.

[0049] Performance test and comparative test, sound insulation performance test: the sound insulation performance test of the prepared high-performance sound insulation material particles was carried out by the standing wave tube method. The results show that at a frequency of 800Hz, the sound insulation volume increased by 20dB, indicating that the sound insulation effect was significantly improved. Comparative test: a common wood chip-based sound insulation material on the market that has not been treated with the modifier of the present invention was selected for the same sound insulation performance test. The results show that the sound insulation volume of the product at a frequency of 800Hz is low, and the sound insulation effect is relatively poor. The high-performance sound insulation material prepared by the present invention is significantly superior to the common unmodified products on the market in terms of sound insulation performance. Mechanical property test: The tensile strength and impact strength of the prepared high-performance sound insulation material particles were tested by a universal material testing machine. The results show that the tensile strength reaches 25MPa and the impact strength reaches 10kJ / m². Comparative test: a common wood chip-based sound insulation material on the market that has not been treated with the modifier of the present invention was selected for the same mechanical property test. The results show that the tensile strength of the product is 18MPa and the impact strength is 6kJ / m². The high-performance sound insulation material prepared by the present invention is significantly superior to the common unmodified products on the market in terms of mechanical properties. Processing performance test: observe the mold filling during the molding process and the appearance quality of the product. The results show that the high-performance sound insulation material of the present invention is completely molded in the twin-screw extruder, and the product appearance is smooth and has no obvious defects. Comparative test: A common wood chip-based sound insulation material on the market that has not been treated with the modifier of the present invention was selected for the same processing performance test. The results show that the product has incomplete mold filling during the molding process and the product appearance has defects. The high-performance sound insulation material prepared by the present invention is significantly superior to the common unmodified products on the market in terms of processing performance.

Claims

1. A method for preparing a high-performance sound insulation material based on waste biomass and an organic modifier, characterized in that: The following steps are involved: S1 waste biomass pretreatment step: collect waste biomass raw materials, remove impurities through manual or mechanical sorting, break them into 0.5-2 cm pieces, place them in a cooking device containing 2%-5% dilute alkali solution, cook them at 100-120℃ for 2-4 hours, rinse them repeatedly with clean water until neutral, dry them at 60-80℃ to constant weight, grind them into 0.1-0.5 mm waste biomass powder for later use; S2 organic modifier synthesis step: in a reactor equipped with temperature control, stirring, condensation reflux and inert gas protection system, 3-amino-4-hydroxybenzoic acid and ethyl chloroacetate are added in a molar ratio of 1:1.3, and triethylamine is added as a catalyst in an amount of 3% by mass of 3-amino-4-hydroxybenzoic acid, and the temperature is raised to 55-65°C under a nitrogen atmosphere and stirred for 8-12 hours to complete the esterification reaction to obtain an intermediate product esterified product, and then the esterified product and allyl alcohol are mixed in a dichloromethane solvent accounting for 40% of the total mass of the raw materials in a molar ratio of 1:1.1, and anhydrous sodium carbonate is added as an acid binding agent in an amount of 1.2 times the mass of the esterified product, and allyl alcohol is added dropwise in an ice bath at 0-3°C, and then the temperature is raised to 45-55°C and stirred for 10-14 hours, and the impurities are filtered out, and the deionized water and ethanol are washed alternately, and the organic modifier 3-amino-4-hydroxybenzoic acid allyl ester with a purity of more than 90% is obtained. Finished product; S3 material mixing and molding step: according to the mass proportions, 40-60 parts of the waste biomass powder, 5-10 parts of the organic modifier, 8-15 parts of the inorganic reinforcing filler, 2-4 parts of the plasticizer and 0.5-1.5 parts of the lubricant are added into a high-speed mixer in sequence, stirred at 90-110°C and 500-800 rpm for 30-40 minutes to form a premix, the premix is ​​input into a twin-screw extruder, the screw speed is 150-200 rpm, the temperature of each section of the extruder from the feed port to the die is set to 160-180°C, 180-200°C, 200-220°C and 220-240°C in sequence, and high-performance sound insulation material particles are obtained through extrusion, cooling and pelletizing.

2. The preparation method according to claim 1, characterized in that: The waste biomass powder accounts for 40-60 parts by mass in the finished product, and the impurity content is less than 0.3% through the combined means of screening, air separation and magnetic separation.

3. The preparation method according to claim 1, characterized in that: The organic modifier accounts for 5-10 parts by mass of the finished product, and an antioxidant is added in an amount of 0.5%-1% of the total mass of the raw materials during the synthesis process to prevent oxidation and deterioration.

4. The preparation method according to claim 1, characterized in that: The inorganic reinforcing filler accounts for 8-15 parts by mass of the finished product, and the inorganic reinforcing filler is one or more combinations of expanded vermiculite and mica powder.

5. The preparation method according to claim 1, characterized in that: The plasticizer is dibutyl phthalate, accounting for 2-4 parts by mass of the finished product; the lubricant is magnesium stearate, accounting for 0.5-1.5 parts by mass of the finished product.

6. A high-performance sound insulation material prepared by the preparation method according to any one of claims 1 to 5, characterized in that: The material comprises, by mass, 40-60 parts of waste biomass powder, 5-10 parts of organic modifier 3-amino-4-hydroxybenzoic acid propylene ester, 8-15 parts of inorganic reinforcing filler, 2-4 parts of plasticizer, and 0.5-1.5 parts of lubricant. The material has the performance indicators of sound insulation of not less than 28dB at low frequencies of 100-1000Hz and not less than 36dB at high frequencies of 1000-5000Hz, tensile strength of not less than 14MPa, elongation at break of not less than 160%, and bending strength of not less than 18MPa.