High-strength sound insulation cotton and preparation method thereof

Abstract

The invention relates to the technical field of sound insulation cotton, and discloses high-strength sound insulation cotton and a preparation method thereof.The sound insulation cotton is prepared by taking polylactic acid as a base material and a diatomite modifier and the like as additives through mixing, extrusion, spinning and needling processes, the macromolecular substance can act with an active group at the tail end of a polylactic acid molecular chain in the subsequent melt extrusion process, so that organic connection between the diatomite and the polylactic acid molecular chain can be realized while the chain extension effect on polylactic acid is realized, and therefore, the interfacial compatibility between the diatomite and the polylactic acid molecular chain is greatly improved; further, the mechanical property of the polylactic acid sound insulation cotton is effectively improved, the sound insulation effect of the polylactic acid sound insulation cotton can be improved through the rich pore structure of the kieselguhr, in addition, the macromolecular substance structure contains rich nitrogen and phosphorus flame-retardant elements, and the flame-retardant property of the sound insulation cotton can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of sound insulation cotton, and in particular to high-strength sound insulation cotton and a preparation method thereof. Background Art

[0002] With the acceleration of urbanization, traffic noise, industrial noise, and architectural acoustics are becoming increasingly prominent, significantly impacting people's lives. Consequently, sound insulation materials have garnered significant research attention in recent years. Traditional sound insulation materials primarily consist of glass fiber, mineral wool, and polyurethane foam, but these materials suffer from drawbacks such as non-degradability, dust pollution, and flammability. Against this backdrop, biodegradable biomaterials have become a research hotspot in the field of green sound insulation. Polylactic acid, in particular, is gradually entering the research and development of sound insulation materials due to its environmental friendliness and unique physical properties.

[0003] Polylactic acid is made from renewable resources such as corn and straw through lactic acid fermentation and polymerization. Its life cycle carbon emissions are more than 60% lower than those of petroleum-based materials. After being discarded, it can be completely degraded within 180 days under industrial composting conditions, so it does not cause environmental pollution problems. In addition, polylactic acid supports a variety of molding processes such as injection, extrusion, and 3D printing, and can be used to prepare complex structure sound insulation components. However, polylactic acid has poor mechanical properties, is relatively brittle, and has low strength, which can cause polylactic acid sound insulation cotton to easily produce microcracks in a vibrating environment, resulting in a decrease in sound absorption effect. In addition, polylactic acid is a flammable material. In the context of frequent fires, its flammability defect also leads to significant restrictions on its further application.

[0004] At present, it is common to enhance and modify polylactic acid through inorganic reinforcement technology. However, there are interface problems between inorganic fillers and polylactic acid. The incompatibility between them will cause the inorganic additives to be unable to efficiently exert their own effectiveness. Based on this, the present invention provides a polylactic acid sound insulation cotton that can solve the problems existing in the prior art. Summary of the Invention

[0005] (1) Technical problems solved In view of the deficiencies in the prior art, the present invention provides a high-strength sound insulation cotton and a preparation method thereof.

[0006] (2) Technical solution A high-strength sound-insulating cotton comprises the following raw materials measured in parts by weight: 65-75 parts of polylactic acid; 3-6.5 parts of diatomaceous earth modifier; 0.5-1 part antioxidant; 4-8 parts of plasticizer; 1-2 parts lubricant; 0.5-1.5 parts of stabilizer; 0.1-0.5 parts of tin catalyst.

[0007] As a further scheme of the present application, the preparation method of the diatomite modifier comprises the following steps: Step one, add diatomite into acetone, after adding, uniformly disperse by ultrasonic, then add surface modifier into the formed dispersion liquid, at the same time, add catalyst, after adding, control the temperature at 30-40℃, continue to heat and stir for 3-6h, then discharge, centrifuge the product, wash, vacuum dry, and obtain diatomite intermediate; Step two, add diatomite intermediate and N,N-dimethylformamide into polymerization kettle, control the ultrasonic frequency at 80-100kHz, ultrasonic treat for 20-30min, then add reactive phosphate derivative into the polymerization kettle, stir for 2-4h under the temperature condition of 30-40℃, then add 5-isocyanate isophthaloyl chloride and catalyst into the polymerization kettle, continue to stir and polymerize for 12-18h, then discharge, collect the solid material, wash, vacuum dry, and obtain diatomite modifier.

[0008] As a further scheme of the present application, the catalyst is triethylamine.

[0009] As a further scheme of the present application, the surface modifier is any one of succinyl chloride, glutaroyl chloride or adipoyl chloride.

[0010] As a further scheme of the present application, the reactive phosphate derivative is prepared by the following method: Add diphenyl phosphinic acid oxirane methyl ester into sulfuric acid solution, after adding, start stirring, after mixing uniformly, increase the temperature to 90-100℃, keep the temperature at 90-100℃ for 1-2h, then stop heating, after natural cooling, separate the product, wash to neutral, then vacuum dry, and obtain reactive phosphate derivative.

[0011] As a further scheme of the present application, the pH value of the sulfuric acid solution is 2-3.

[0012] As a further scheme of the present application, the mass ratio of diatomite intermediate, reactive phosphate derivative and 5-isocyanate isophthaloyl chloride is 1:0.3-0.6:0.1-0.3.

[0013] In the above technical solution, a surface modifier is first used to modify the surface of diatomite so that the surface of the diatomite can carry active acyl chloride groups to prepare a diatomite intermediate material. Due to the high activity of the acyl chloride groups, the acyl chloride groups of the diatomite intermediate material can condense with the active hydroxyl groups in the reactive phosphate derivative structure, and at the same time act as an intermediate. Under low temperature conditions, they continuously condense with the acyl chloride groups in the 5-isocyanate isophthaloyl chloride structure, thereby modifying the surface of the diatomite with ester bonds and forming a macromolecular substance having a front-segment alternating structure to prepare a diatomite modifier.

[0014] The reactive phosphate derivative is prepared by using diphenylphosphite oxirane methyl ester as raw material, and the epoxy group in its structure is hydrolyzed under the action of sulfuric acid to form two equivalents of active hydroxyl groups.

[0015] As a further embodiment of the present invention, the antioxidant is at least one of antioxidant 1010, antioxidant 168, antioxidant 1076 or antioxidant BHT; and the plasticizer is dioctyl phthalate or dibutyl phthalate.

[0016] As a further embodiment of the present invention, the lubricant is polyethylene wax or liquid paraffin; the stabilizer is a calcium zinc stabilizer; and the tin catalyst is any one of dibutyltin dilaurate, stannous octoate, dimethyltin mercaptan, or octyltin mercaptan.

[0017] A method for preparing high-strength sound insulation cotton comprises the following steps: The first step is to weigh and prepare all the raw materials according to their weight. The second step is to put all the raw materials into a mixer, control the temperature to 90-100℃, and mechanically stir and mix them evenly. Then transfer the formed mixture to a twin-screw extruder, control the temperature to 200-220℃, melt extrude, and then spin through a nozzle to form fibers. The surface density is controlled to 400-500g / m 2 , acupuncture density is 260-280 needles / cm 2 , sound insulation cotton can be made through needle punching process.

[0018] (3) Beneficial technical effects The diatomite modifier is prepared by modifying macromolecular substances on the surface of diatomite, and the macromolecular substances contain isocyanate groups in the structure, which can react with active groups at the end of the polylactic acid molecular chain under the action of tin catalyst in the subsequent melt extrusion process, so as to achieve chain extension of polylactic acid and organic connection between diatomite and the polylactic acid molecular chain, thereby greatly improving the interfacial compatibility between them, enabling diatomite to be uniformly dispersed in polylactic acid, and further efficiently playing the advantages of diatomite as an inorganic additive to improve the mechanical properties of polylactic acid acoustic cotton. In addition, diatomite itself has a rich pore structure, and sound wave energy can be converted into heat energy through mechanisms such as viscous friction, heat conduction and resonance with the pores, thereby improving the sound insulation effect of polylactic acid acoustic cotton. In addition, the macromolecular substance structure contains rich nitrogen and phosphorus flame-retardant elements, which can quickly form an expanded carbon layer to prevent combustion from continuing when combustion occurs, thereby effectively improving the flame-retardant performance of the acoustic cotton. DETAILED DESCRIPTION

[0019] In order to facilitate the understanding of the present application, the present application will be described more fully below. The preferred embodiments of the present application are given below. However, the present application can be realized in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present application more thorough and comprehensive.

[0020] Preparation Example Preparation of diatomite modifier: Step S1, 1.5g of diatomite was added to acetone, after addition, ultrasonic dispersion was uniform, then 0.5g of adipoyl chloride was added to the formed dispersion liquid, while 0.1g of triethylamine was added, after addition, the temperature was controlled at 35℃, and the stirring was continued for 4h, then the product was discharged and centrifuged, washed, and vacuum dried to obtain diatomite intermediate; Step S2, 0.3g of diphenyl phosphinic acid oxirane methyl ester was added to a sulfuric acid solution with a pH value of 2, after addition, stirring was started, and after mixing uniformly, the temperature was increased to 90℃, and kept for 1h, then the heating was stopped, and after natural cooling, the product was separated, washed to neutral, and then vacuum dried to prepare a reaction type phosphate derivative; Step S3, 1.2g of diatomite intermediate and N,N-dimethylformamide were added to a polymerization kettle, ultrasonic frequency was controlled at 100kHz, and ultrasonic treatment was carried out for 30min, then 0.6g of reaction type phosphate derivative was added to the polymerization kettle, stirring was carried out at a temperature of 35℃ for 3h, then 0.2g of 5-isocyanate isophthaloyl chloride and 0.1g of triethylamine were added to the polymerization kettle, and the stirring and polymerization were continued for 16h, then the product was discharged, the solid material was collected, washed, and vacuum dried to prepare the diatomite modifier.

[0021] Diatomaceous earth was purchased from Shanghai MacLean Biochemical Technology Co., Ltd. with product number D858223.

[0022] Example 1: A high-strength sound-insulating cotton comprising the following raw materials measured in parts by weight: 65 parts of polylactic acid; 3 parts of diatomaceous earth modifier; 0.5 parts of antioxidant 1010; 4 parts of dioctyl phthalate; 1 part polyethylene wax; 0.5 parts of calcium zinc stabilizer; 0.1 parts of dibutyltin dilaurate.

[0023] The preparation method of the sound insulation cotton comprises the following steps: The first step is to weigh and prepare all the raw materials according to their weight. In the second step, all raw materials were put into a mixer, the temperature was controlled at 90°C, and the mixture was mechanically stirred to mix evenly. Then the mixture was transferred to a twin-screw extruder, the temperature was controlled at 200°C, and melt extrusion was performed. Then, the mixture was spun through a nozzle to form fibers, and the surface density was controlled to be 450g / m 2 , acupuncture density is 268 needles / cm 2 , sound insulation cotton can be made through needle punching process.

[0024] The polylactic acid was purchased from Shanghai MacLean Biochemical Technology Co., Ltd. with the product number P921577. The preparation method of the diatomaceous earth modifier is shown in the preparation example, and the same is true for the following.

[0025] Example 2: A high-strength sound-insulating cotton comprising the following raw materials measured in parts by weight: 68 parts of polylactic acid; 5.5 parts of diatomaceous earth modifier; Antioxidant BHT 0.6 parts; 6 parts of dibutyl phthalate; 1.5 parts of polyethylene wax; 1 part calcium zinc stabilizer; 1 part of dibutyltin dilaurate.

[0026] The preparation method of the sound insulation cotton comprises the following steps: The first step is to weigh and prepare all the raw materials according to their weight. In the second step, all raw materials were put into a blender, the temperature was controlled at 100°C, and the mixture was mechanically stirred and mixed evenly. Then the mixture was transferred to a twin-screw extruder, the temperature was controlled at 210°C, and melt extrusion was performed. Then, the mixture was spun through a nozzle to form fibers, and the surface density was controlled to be 450g / m 2 , acupuncture density is 268 needles / cm 2 , sound insulation cotton can be made through needle punching process.

[0027] Example 3: A high-strength sound-insulating cotton comprising the following raw materials measured in parts by weight: 75 parts of polylactic acid; 6.5 parts of diatomaceous earth modifier; 1 part of antioxidant BHT; 8 parts of dibutyl phthalate; 2 parts of polyethylene wax; 1.5 parts of calcium zinc stabilizer; 0.5 parts of dibutyltin dilaurate.

[0028] The preparation method of the sound insulation cotton comprises the following steps: The first step is to weigh and prepare all the raw materials according to their weight. In the second step, all raw materials were put into a blender, the temperature was controlled at 100°C, and the mixture was mechanically stirred and mixed evenly. Then the mixture was transferred to a twin-screw extruder, the temperature was controlled at 220°C, and melt extrusion was performed. Then, the mixture was spun through a nozzle to form fibers, and the surface density was controlled to be 450g / m 2 , acupuncture density is 268 needles / cm 2 , sound insulation cotton can be made through needle punching process.

[0029] Comparative Example 1: A high-strength sound-insulating cotton comprises the following raw materials measured in parts by weight: 68 parts of polylactic acid; 5.5 parts of diatomaceous earth; Antioxidant BHT 0.6 parts; 6 parts of dibutyl phthalate; 1.5 parts of polyethylene wax; 1 part calcium zinc stabilizer; 1 part of dibutyltin dilaurate.

[0030] The preparation method of the sound insulation cotton comprises the following steps: The first step is to weigh and prepare all the raw materials according to their weight. The second step is to put each raw material into a blender, control the temperature to be 100 DEG C, mechanically stir and mix uniformly, then transfer the formed mixture to a twin-screw extruder, control the temperature to be 210 DEG C, melt extrude, then spray through a nozzle to form fibers, control the area density to be 450 g / m 2 , the needling density is 268 needles / cm 2 , and the sound insulation cotton can be obtained through the needling process.

[0031] Comparative Example 2 A high-strength sound insulation cotton comprises the following raw materials measured by weight fraction: 68 parts of polylactic acid; 0.6 parts of antioxidant BHT; 6 parts of dibutyl phthalate; 1.5 parts of polyethylene wax; 1 part of calcium-zinc stabilizer; 1 part of dibutyltin dilaurate.

[0032] The preparation method of the sound insulation cotton comprises the following steps: The first step is to weigh each raw material according to the weight fraction of each raw material; The second step is to put each raw material into a blender, control the temperature to be 100 DEG C, mechanically stir and mix uniformly, then transfer the formed mixture to a twin-screw extruder, control the temperature to be 210 DEG C, melt extrude, then spray through a nozzle to form fibers, control the area density to be 450 g / m 2 , the needling density is 268 needles / cm 2 , and the sound insulation cotton can be obtained through the needling process.

[0033] Test Example The sound insulation coefficients of the sound insulation cottons in the examples and comparative examples are tested according to the reference standard GB / T 18696.2-2002, the sample thickness is 5 mm, and the frequency is 1000 Hz; The oxygen index test is performed according to the reference standard GB / T 5454-1997; The mechanical property test is performed according to the reference standard GB / T 14337-2022; The results are shown in the following table:

[0034] According to the test results, the sound insulation cotton prepared in the examples of the present application has excellent performance, and after replacing the diatomite modifier with diatomite, on the one hand, there is an interface problem between the diatomite and the polylactic acid, which cannot be uniformly dispersed, resulting in the failure to efficiently play the modification advantage, and therefore the performance is greatly reduced.

[0035] Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas, including the best mode, and also enables any technician in this field to practice the present invention, including implementing any combined methods. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements that are similar to the literal expression of the claims, or if they include equivalent structural elements that are not substantially different from the literal expression of the claims, then these other embodiments should also be included in the scope of the claims.

[0036] Based on the ideal embodiments of the present invention, and with reference to the above description, relevant personnel can make various changes and modifications without departing from the technical scope of the present invention. The technical scope of the present invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A high-strength sound insulation cotton, characterized in that, The following raw materials are included in parts by weight: 65-75 parts of polylactic acid; 3-6.5 parts of diatomaceous earth modifier; 0.5-1 part antioxidant; 4-8 parts of plasticizer; 1-2 parts lubricant; 0.5-1.5 parts of stabilizer; 0.1-0.5 parts of tin catalyst; The preparation method of the diatomite modifier comprises the following steps: Step 1: Add diatomaceous earth to acetone, disperse it evenly by ultrasonication, then add the surface modifier to the formed dispersion, and add the catalyst at the same time. After the addition is completed, control the temperature to 30-40°C, keep stirring for 3-6 hours, discharge the material, centrifuge the product, wash it, and vacuum dry it to obtain a diatomaceous earth intermediate material; Step 2: Add the diatomite intermediate material and N,N-dimethylformamide to the polymerization kettle, control the ultrasonic frequency to 80-100 kHz, and after ultrasonic treatment for 20-30 minutes, add the reactive phosphate derivative to the polymerization kettle, stir at a temperature of 30-40° C. for 2-4 hours, and then add 5-isocyanate isophthalic acid chloride and a catalyst to the polymerization kettle. After continuous stirring and polymerization for 12-18 hours, discharge the material, collect the solid material, wash it, and vacuum dry it to obtain a diatomite modifier.

2. The high-strength sound insulation cotton according to claim 1, characterized in that: The catalyst is triethylamine.

3. The high-strength sound insulation cotton according to claim 1, characterized in that: The surface modifier is any one of succinyl chloride, glutaryl chloride or adipoyl chloride.

4. The high-strength sound insulation cotton according to claim 1, characterized in that: The reactive phosphate derivative is prepared by the following method: Add diphenyl phosphinate oxirane methyl ester to sulfuric acid solution, start stirring after addition, mix evenly, raise the temperature to 90-100°C, maintain this temperature for 1-2 hours, stop heating, allow to cool naturally, separate the product, wash to neutrality, and then vacuum dry to obtain a reactive phosphate derivative.

5. The high-strength sound insulation cotton according to claim 4, characterized in that: The pH value of the sulfuric acid solution is 2-3.

6. The high-strength sound insulation cotton according to claim 1, characterized in that: The mass ratio of the diatomaceous earth intermediate material, the reactive phosphate derivative and 5-isocyanate isophthalic acid chloride is 1:0.3-0.6:0.1-0.

3.

7. The high-strength sound insulation cotton according to claim 1, characterized in that: The antioxidant is at least one of antioxidant 1010, antioxidant 168, antioxidant 1076 or antioxidant BHT; and the plasticizer is dioctyl phthalate or dibutyl phthalate.

8. The high-strength sound insulation cotton according to claim 1, characterized in that: The lubricant is polyethylene wax or liquid paraffin; the stabilizer is calcium zinc stabilizer; and the tin catalyst is any one of dibutyltin dilaurate, stannous octoate, dimethyltin mercaptan, or octyltin mercaptan.

9. A method for preparing the high-strength sound insulation cotton according to claim 1, characterized in that: The following steps are involved: The first step is to weigh and prepare all the raw materials according to their weight. The second step is to put all the raw materials into a mixer, control the temperature to 90-100℃, and mechanically stir and mix them evenly. Then transfer the formed mixture to a twin-screw extruder, control the temperature to 200-220℃, melt extrude, and then spin through a nozzle to form fibers. The surface density is controlled to 400-500g / m 2 , acupuncture density is 260-280 needles / cm 2 , sound insulation cotton can be made through needle punching process.

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