CN113698701A - Sound insulation material and preparation method and application thereof - Google Patents
Sound insulation material and preparation method and application thereof Download PDFInfo
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- CN113698701A CN113698701A CN202110918188.8A CN202110918188A CN113698701A CN 113698701 A CN113698701 A CN 113698701A CN 202110918188 A CN202110918188 A CN 202110918188A CN 113698701 A CN113698701 A CN 113698701A
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- 239000004372 Polyvinyl alcohol Substances 0.000 claims abstract description 69
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- 239000002159 nanocrystal Substances 0.000 claims abstract description 68
- 229920000642 polymer Polymers 0.000 claims abstract description 29
- 238000002156 mixing Methods 0.000 claims abstract description 23
- 239000002270 dispersing agent Substances 0.000 claims abstract description 18
- 238000010525 oxidative degradation reaction Methods 0.000 claims abstract description 16
- 239000011810 insulating material Substances 0.000 claims abstract description 14
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 12
- 238000001746 injection moulding Methods 0.000 claims abstract description 7
- 238000000034 method Methods 0.000 claims description 35
- 238000006243 chemical reaction Methods 0.000 claims description 27
- JHJLBTNAGRQEKS-UHFFFAOYSA-M sodium bromide Chemical compound [Na+].[Br-] JHJLBTNAGRQEKS-UHFFFAOYSA-M 0.000 claims description 24
- SUKJFIGYRHOWBL-UHFFFAOYSA-N sodium hypochlorite Chemical compound [Na+].Cl[O-] SUKJFIGYRHOWBL-UHFFFAOYSA-N 0.000 claims description 24
- 239000000243 solution Substances 0.000 claims description 24
- 239000005708 Sodium hypochlorite Substances 0.000 claims description 23
- 239000000835 fiber Substances 0.000 claims description 19
- 238000009413 insulation Methods 0.000 claims description 17
- 239000002002 slurry Substances 0.000 claims description 16
- YAXWOADCWUUUNX-UHFFFAOYSA-N 1,2,2,3-tetramethylpiperidine Chemical compound CC1CCCN(C)C1(C)C YAXWOADCWUUUNX-UHFFFAOYSA-N 0.000 claims description 10
- RKMGAJGJIURJSJ-UHFFFAOYSA-N 2,2,6,6-Tetramethylpiperidine Substances CC1(C)CCCC(C)(C)N1 RKMGAJGJIURJSJ-UHFFFAOYSA-N 0.000 claims description 10
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 claims description 9
- 230000008569 process Effects 0.000 claims description 8
- 238000004519 manufacturing process Methods 0.000 claims description 6
- 239000004743 Polypropylene Substances 0.000 claims description 5
- 229920001155 polypropylene Polymers 0.000 claims description 5
- -1 polypropylene Polymers 0.000 claims description 4
- LBLYYCQCTBFVLH-UHFFFAOYSA-N 2-Methylbenzenesulfonic acid Chemical compound CC1=CC=CC=C1S(O)(=O)=O LBLYYCQCTBFVLH-UHFFFAOYSA-N 0.000 claims description 3
- OWQGBDSLJUVLKF-UHFFFAOYSA-N 2-dodecylpyridine Chemical compound CCCCCCCCCCCCC1=CC=CC=N1 OWQGBDSLJUVLKF-UHFFFAOYSA-N 0.000 claims description 3
- 239000007788 liquid Substances 0.000 claims description 3
- 229920002635 polyurethane Polymers 0.000 claims description 3
- 239000004814 polyurethane Substances 0.000 claims description 3
- 229920000915 polyvinyl chloride Polymers 0.000 claims description 3
- 239000004800 polyvinyl chloride Substances 0.000 claims description 3
- 229940077386 sodium benzenesulfonate Drugs 0.000 claims description 3
- MZSDGDXXBZSFTG-UHFFFAOYSA-M sodium;benzenesulfonate Chemical compound [Na+].[O-]S(=O)(=O)C1=CC=CC=C1 MZSDGDXXBZSFTG-UHFFFAOYSA-M 0.000 claims description 3
- DAJSVUQLFFJUSX-UHFFFAOYSA-M sodium;dodecane-1-sulfonate Chemical compound [Na+].CCCCCCCCCCCCS([O-])(=O)=O DAJSVUQLFFJUSX-UHFFFAOYSA-M 0.000 claims description 3
- 239000012295 chemical reaction liquid Substances 0.000 claims description 2
- JMGZBMRVDHKMKB-UHFFFAOYSA-L disodium;2-sulfobutanedioate Chemical compound [Na+].[Na+].OS(=O)(=O)C(C([O-])=O)CC([O-])=O JMGZBMRVDHKMKB-UHFFFAOYSA-L 0.000 claims description 2
- 239000000463 material Substances 0.000 abstract description 48
- 238000013016 damping Methods 0.000 abstract description 26
- 239000001257 hydrogen Substances 0.000 abstract description 19
- 229910052739 hydrogen Inorganic materials 0.000 abstract description 19
- 239000002861 polymer material Substances 0.000 abstract description 5
- 230000000694 effects Effects 0.000 description 16
- 238000007254 oxidation reaction Methods 0.000 description 12
- 230000003647 oxidation Effects 0.000 description 10
- 230000009286 beneficial effect Effects 0.000 description 7
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- GDOPTJXRTPNYNR-UHFFFAOYSA-N methyl-cyclopentane Natural products CC1CCCC1 GDOPTJXRTPNYNR-UHFFFAOYSA-N 0.000 description 6
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- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
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- 230000002378 acidificating effect Effects 0.000 description 2
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- JOXIMZWYDAKGHI-UHFFFAOYSA-N toluene-4-sulfonic acid Chemical compound CC1=CC=C(S(O)(=O)=O)C=C1 JOXIMZWYDAKGHI-UHFFFAOYSA-N 0.000 description 2
- 229920001046 Nanocellulose Polymers 0.000 description 1
- 230000009471 action Effects 0.000 description 1
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- 239000007864 aqueous solution Substances 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 238000010504 bond cleavage reaction Methods 0.000 description 1
- 230000003139 buffering effect Effects 0.000 description 1
- DUMIASQJCCZABP-UHFFFAOYSA-N butanedioic acid;sodium Chemical compound [Na].OC(=O)CCC(O)=O DUMIASQJCCZABP-UHFFFAOYSA-N 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
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- 229910052979 sodium sulfide Inorganic materials 0.000 description 1
- GRVFOGOEDUUMBP-UHFFFAOYSA-N sodium sulfide (anhydrous) Chemical compound [Na+].[Na+].[S-2] GRVFOGOEDUUMBP-UHFFFAOYSA-N 0.000 description 1
- 239000012257 stirred material Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- BDHFUVZGWQCTTF-UHFFFAOYSA-M sulfonate Chemical compound [O-]S(=O)=O BDHFUVZGWQCTTF-UHFFFAOYSA-M 0.000 description 1
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
- C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
- C08L23/10—Homopolymers or copolymers of propene
- C08L23/12—Polypropene
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G81/00—Macromolecular compounds obtained by interreacting polymers in the absence of monomers, e.g. block polymers
- C08G81/02—Macromolecular compounds obtained by interreacting polymers in the absence of monomers, e.g. block polymers at least one of the polymers being obtained by reactions involving only carbon-to-carbon unsaturated bonds
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2201/00—Properties
- C08L2201/08—Stabilised against heat, light or radiation or oxydation
Abstract
The invention discloses a sound insulation material and a preparation method and application thereof. The preparation method comprises the following steps: (1) carrying out oxidative degradation on cellulose under alkaline conditions so as to obtain cellulose nanocrystals; (2) mixing and reacting the cellulose nanocrystals, polyvinyl alcohol, a dispersing agent and water to obtain cellulose nanocrystal modified polyvinyl alcohol; (3) mixing the modified polyvinyl alcohol with a polymer and injection molding to obtain the sound insulating material. According to the preparation method, the hydrogen bond density of polymer molecules is improved by modifying the polymer material, so that the material use performance requirement is met, and a better damping characteristic is obtained, so that better NVH (noise vibration harshness) silence is obtained.
Description
Technical Field
The invention belongs to the field of materials, and particularly relates to a sound insulation material as well as a preparation method and application thereof.
Background
With the social development, the automobile holding capacity is gradually increased, and the influence of vehicle noise on the life of people is larger and larger, so that the general attention is attracted. It is shown by the relevant data that 75% of urban noise originates from traffic noise, which is mainly car noise. Noise not only affects work, study, rest, mood and the like of people, but also interferes with communication, and diseases and other hazards are easily caused. At present, reducing the influence of noise on people has become one of the important social concerns.
Disclosure of Invention
The present invention is directed to solving, at least to some extent, one of the technical problems in the related art. To this end, it is an object of the present invention to propose sound-insulating materials, a process for their preparation and their use. According to the preparation method, the hydrogen bond density of polymer molecules is improved by modifying the polymer material, so that the material use performance requirement is met, and a better damping characteristic is obtained, so that better NVH (noise vibration harshness) silence is obtained.
The present invention is proposed mainly based on the following findings of the inventors:
the honeycomb material is a high-quality light material, has light weight, high strength and high rigidity, has the functions of buffering, heat insulation, sound insulation and the like, is widely applied to the building industry, furniture manufacturing, packaging and transportation industry, has higher economic value, can be recycled, can save a large amount of resources at the same time, protects and improves the ecological environment, and is an environment-friendly novel material which accords with the development theme of the century. The honeycomb material is composed of a plurality of honeycomb net structures, so that air vibration can be effectively controlled, and noise transmission generated when a vehicle runs on a road and an engine works is reduced; the composition materials of the honeycomb structure also have important influence on the performance of the honeycomb. Further, polymer materials are widely applied to damping materials due to inherent viscoelasticity, and the nature of the damping performance of the polymer is internal consumption caused by mutual friction of molecular chains in a forced vibration process, so that mechanical energy is converted into other forms of energy to be dissipated; in addition, the polymer can be self-assembled into a supramolecular polymer elastomer under the action of hydrogen bonds, so that the mutual friction among intramolecular chain segments is greatly increased, the dissipation of external mechanical energy is accelerated, the loss modulus of the material and the maximum value of a loss factor are improved, namely the improvement of the hydrogen bond density of the polymer is beneficial to optimizing the damping characteristic of the polymer. Therefore, the polymer material for the vehicle can be modified properly, the hydrogen bond density of polymer molecules is improved, the service performance requirement is met, and meanwhile, the better damping characteristic is obtained, so that the better NVH silent performance is obtained.
To this end, according to a first aspect of the invention, the invention proposes a method for preparing a sound-insulating material. According to an embodiment of the invention, the method comprises:
(1) carrying out oxidative degradation on cellulose under alkaline conditions so as to obtain cellulose nanocrystals;
(2) mixing and reacting the cellulose nanocrystals, polyvinyl alcohol, a dispersing agent and water to obtain cellulose nanocrystal modified polyvinyl alcohol;
(3) mixing the modified polyvinyl alcohol with a polymer and injection molding to obtain the sound insulating material.
The method for preparing the sound insulation material of the above embodiment of the present invention has at least the following beneficial effects: 1) by carrying out oxidative degradation on cellulose under an alkaline condition, the problem that hydrogen bonds in the cellulose are broken due to an acidic oxidation condition, and the modification effect of cellulose nanocrystals on polyvinyl alcohol is further reduced can be avoided; 2) the grafting concentration of the cellulose nanocrystals in the sound insulation material can be flexibly adjusted by adjusting the ratio of the cellulose nanocrystals to the polyvinyl alcohol and the ratio of the modified polyvinyl alcohol to the polymer, and the hydrogen bond density of polymer molecules is improved, so that excellent sound insulation performance is obtained; 3) the sound insulation material with an expected structure, such as a honeycomb network structure, can be obtained according to injection molding, so that the effects of improving the sound insulation performance and lightening the material are achieved; 4) the prepared sound insulation material has the advantages of high strength, good thermal stability, low expansion coefficient, good sound insulation performance and the like, can meet the requirements of material use performance and obtain better damping characteristic, thereby obtaining better NVH silent performance and having wide application prospect in the aspects of noise reduction in the field of automobiles.
In addition, the method of preparing the soundproof material according to the above embodiment of the present invention may further have the following additional technical features:
in some embodiments of the invention, step (1) comprises: dissociating the cellulose to obtain a dissociated fiber slurry; mixing the fiber slurry with sodium bromide, tetramethylpiperidine and sodium hypochlorite to obtain a reaction solution; and adjusting the pH value of the reaction solution to be alkaline to carry out oxidative degradation so as to obtain the cellulose nanocrystals.
In some embodiments of the invention, step (1) satisfies at least one of the following conditions: the mass concentration of the fiber slurry is 1-5 wt%, the sodium hypochlorite is a sodium hypochlorite solution with the concentration of 85-95 wt%, and the mass ratio of the fiber slurry to the sodium bromide to the tetramethyl piperidine is 100: (0.05-0.3): (0.005-0.1), wherein the solid-to-liquid ratio of the fiber pulp to the sodium hypochlorite solution is 100 g: (2-5) mL; controlling the pH value of the reaction liquid to be 9-11 all the time in the oxidative degradation process; the temperature of the oxidative degradation is 0-20 ℃, and the time is 6-48 h; the size of the cellulose nanocrystal is 0.3-2 mu m; the cellulose nanocrystal comprises 25-35% of carboxyl.
In some embodiments of the invention, step (2) comprises: mixing the polyvinyl alcohol with a dispersant and water to obtain a polyvinyl alcohol solution; and mixing and reacting the cellulose nanocrystals with the polyvinyl alcohol solution to obtain cellulose nanocrystal modified polyvinyl alcohol.
In some embodiments of the invention, step (2) satisfies at least one of the following conditions: the mass ratio of the polyvinyl alcohol to the dispersing agent to the cellulose nanocrystals is 10: (0.1-0.5): (0.5 to 5); the temperature of the mixing reaction is 50-70 ℃, and the time is 0.5-5 h; the dispersant is at least one selected from toluene sulfonic acid, sodium benzene sulfonate, sodium dodecyl sulfonate, sodium sulfosuccinate and dodecyl pyridine.
In some embodiments of the invention, step (3) satisfies at least one of the following conditions: the polymer is at least one selected from polypropylene, polyvinyl chloride and polyurethane; the proportion of the modified polyvinyl alcohol in the sound insulation material is 5-50 wt%; the sound insulation material is of a honeycomb net structure.
In some embodiments of the invention, the honeycomb is a regular hexagon.
In some embodiments of the invention, the thickness of the honeycomb is 5-100 mm, the side length of the inclined side of the honeycomb core is 2-50 mm, the wall thickness of the honeycomb core is 0.2-4 mm, and the thickness of the honeycomb panel is 0.5-10 mm.
According to a second aspect of the present invention, a sound insulating material is provided. According to an embodiment of the present invention, the soundproof material is manufactured by the method for manufacturing the soundproof material described above. Compared with the prior art, the sound insulation material has higher hydrogen bond concentration, can greatly increase the mutual friction among the chain segments in the polymer molecules through the breakage and recombination of the hydrogen bonds in the using process, accelerates the dissipation of external mechanical energy, and obviously improves the damping performance of the sound insulation material; in addition, the sound insulation material also has the advantages of high strength, good thermal stability, low expansion coefficient, good sound insulation performance and the like, can meet the requirements of material use performance and simultaneously obtain better damping characteristics, particularly can further improve the sound insulation performance and achieve the effect of light weight when the sound insulation material has a honeycomb network structure, and can be widely applied to the field of automobiles as the sound insulation material for vehicles.
According to a third aspect of the present invention, a vehicle is provided. According to an embodiment of the present invention, the vehicle includes the above-described soundproof material or the soundproof material produced by the above-described method of producing a soundproof material. In the prior art, the noise generated by the vehicle during road running and engine working is less spread, and the noise transmission method has very important significance for reducing traffic noise, urban noise and various hazards generated by noise.
Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Drawings
The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
FIG. 1 is a flow chart of a method of making an acoustic barrier material according to one embodiment of the present invention.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.
According to a first aspect of the present invention, a method of making an acoustic barrier material is presented. According to an embodiment of the invention, as shown in fig. 1, the method comprises: (1) carrying out oxidative degradation on cellulose under alkaline conditions so as to obtain cellulose nanocrystals; (2) mixing cellulose nanocrystals, polyvinyl alcohol, a dispersing agent and water for reaction so as to obtain cellulose nanocrystal modified polyvinyl alcohol; (3) the modified polyvinyl alcohol is mixed with a polymer and injection-molded to obtain a sound-insulating material. According to the method, the hydrogen bond density of polymer molecules is improved by modifying the polymer material, so that the material use performance requirement is met, and a better damping characteristic is obtained, and thus better NVH (noise vibration harshness) silence is obtained.
The method for preparing the soundproof material according to the above embodiment of the present invention will be described in detail with reference to fig. 1.
S100, carrying out oxidative degradation on cellulose under alkaline condition to obtain cellulose nanocrystals
According to the embodiment of the invention, the cellulose can be dissociated in advance to obtain dissociated fiber slurry; mixing the fiber slurry with sodium bromide, tetramethyl piperidine and sodium hypochlorite to obtain a reaction solution; and finally, adjusting the pH value of the reaction solution to be alkaline for oxidative degradation so as to obtain the cellulose nanocrystals. The sodium hypochlorite has stronger oxidizability in an alkaline environment, the cellulose contains a large number of hydroxyl groups, the sodium hypochlorite can oxidize a part of the hydroxyl groups to form carboxyl groups, the polarity of the carboxyl groups is stronger, more hydrogen bonds can be formed by combining water molecules, the molecular weight and the size of the cellulose are larger, and the sodium hypochlorite can also break macromolecular chains in the oxidation process to form micro-nano cellulose nanocrystals with smaller sizes; tetramethyl piperidine (TEMPO) and sodium hypochlorite are used cooperatively, can guarantee the oxidation effect on the one hand, can also form certain weak combination through sharing electron pair between on the other hand tetramethyl piperidine and the cellulose, more be favorable to controlling cellulose nanocrystal's size, and sodium bromide is used for providing certain polarity, maintains the oxidizing environment and promotes going on of oxidation reaction. The inventor finds that compared with other oxidation systems (such as sodium sulfide and the like), the oxidation system adopting sodium hypochlorite, sodium bromide and tetramethylpiperidine has the advantages of mild and easily controlled reaction and uniform size distribution of finally obtained cellulose nanocrystals.
According to an embodiment of the invention, the mass concentration of the fiber slurry may be 1-5 wt%, the sodium hypochlorite may be a sodium hypochlorite solution with a concentration of 85-95 wt%, and the mass ratio of the fiber slurry, the sodium bromide and the Tetramethylpiperidine (TEMPO) may be 100: (0.05-0.3): (0.005-0.1), the solid-to-liquid ratio of the fiber pulp to the sodium hypochlorite solution can be 100 g: (2 to 5) mL, for example, the mass concentration of the fiber slurry may be 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, or 5 wt%, etc., and the sodium hypochlorite solution may be a commercially available product, and the concentration thereof may be 87 wt%, 89 wt%, 91 wt%, 93 wt%, or 95 wt%, etc.; the sodium bromide may be used in an amount of 0.05, 0.1, 0.15, 0.2, 0.25, or 0.3, etc. parts by weight, the tetramethylpiperidine may be used in an amount of 0.005, 0.008, 0.01, 0.03, 0.05, 0.07, or 0.09, etc. parts by weight, and the sodium hypochlorite solution may be used in an amount of 2mL, 2.5mL, 3mL, 3.5mL, 4mL, 4.5mL, or 5mL, etc. by volume, based on 100 parts by weight of the fiber slurry. The inventors found that if the concentration of cellulose in the fiber slurry is too high, the polymer chains tend to agglomerate or curl, which is not conducive to obtaining cellulose nanocrystals with smaller size or uniform size distribution; if the amount of sodium hypochlorite is too small, the oxidation effect on cellulose is not obvious, and more carboxyl groups are difficult to obtain; if the amount of the sodium bromide is too small, the effect of promoting the oxidation reaction is not obvious; if the TEMPO dosage is too small, the TEMPO is not favorable for forming a stable oxidation system with sodium hypochlorite; if the amount of sodium hypochlorite, TEMPO or sodium bromide is too much, the raw materials are easily wasted. According to the invention, by controlling the raw material ratio, the content of carboxyl in the cellulose nanocrystal can be obviously improved, the size of the cellulose nanocrystal can be more uniform and stable, and specifically, the cellulose nanocrystal with the carboxyl content of 25-35% and the size of 0.3-2 μm can be obtained, so that when the cellulose nanocrystal is used for modifying polyvinyl alcohol and preparing a polymer sound insulation material, the mutual friction among chain segments in molecules can be greatly increased, the dissipation of external mechanical energy is accelerated, and the damping performance of the polymer can be improved.
According to another embodiment of the present invention, the pH of the reaction solution can be controlled to be 9-11, for example, the pH of the reaction solution can be controlled to be 9.5, 10 or 10.5, etc. in the oxidative degradation process, the inventors have found that the control of the alkaline condition can further increase the electrode potential, and maintain the stability of the oxidation environment of the oxidation system and the strong oxidizing property of sodium hypochlorite, thereby being more beneficial to obtaining cellulose nanocrystals with higher carboxyl content and uniform size.
According to another embodiment of the present invention, the temperature of the oxidative degradation may be 0 to 20 ℃, for example, 0 ℃, 5 ℃, 10 ℃ or 15 ℃, and the time may be 6 to 48 hours, for example, 8 hours, 16 hours or 24 hours, and the inventors found that if the reaction temperature is too high, the reaction is too violent, the reaction degree is not easy to control, if the reaction time is too short, the reaction is difficult to sufficiently proceed, and if the reaction time is too long, the reaction efficiency is affected.
According to another embodiment of the present invention, the cellulose in the present invention is not particularly limited, and those skilled in the art can select the cellulose according to actual needs, for example, the cellulose may be lignocellulose, etc.
S200, mixing and reacting the cellulose nanocrystals, polyvinyl alcohol, a dispersing agent and water to obtain cellulose nanocrystal modified polyvinyl alcohol
According to the embodiment of the invention, polyvinyl alcohol (PVA) can provide a framework for the sound insulation polymer on one hand, and on the other hand, PVA also contains a certain free radical which can interact with oxygen in the hydroxyl group of the cellulose nanocrystal to strengthen the acting force between molecules. In addition, carboxyl groups in cellulose nanocrystals can combine with water to form a large number of hydrogen bonds, which are relatively rigid and consume a large amount of energy when subjected to external forces by hydrogen bond cleavage and recombination. Therefore, after the polyvinyl alcohol is modified by the cellulose nanocrystals, when the polyvinyl alcohol is subjected to an external force, the conversion of the external mechanical energy and the friction force between the intramolecular segments can be realized through the fracture recombination of the hydrogen bonds and the intermolecular acting force, so that the damping performance is greatly improved.
According to an embodiment of the present invention, the polyvinyl alcohol may be mixed with the dispersant and water to obtain a polyvinyl alcohol solution, for example, the polyvinyl alcohol may be heated to 90 ℃ and fully dissolved in water under stirring, and then the cellulose nanocrystals and the polyvinyl alcohol solution are mixed and reacted to obtain the cellulose nanocrystal modified polyvinyl alcohol, which may be more beneficial to fully and uniformly mixing the cellulose nanocrystals and the polyvinyl alcohol. It should be noted that the kind of the dispersant in the present invention is not particularly limited, and may be selected by those skilled in the art according to actual needs, for example, the dispersant may be at least one selected from the group consisting of toluene sulfonic acid, sodium benzene sulfonate, sodium dodecyl sulfonate, sodium succinic acid sulfonate, and dodecyl pyridine.
According to still another embodiment of the present invention, the mass ratio of the polyvinyl alcohol, the dispersing agent and the cellulose nanocrystals may be 10: (0.1-0.5): (0.5 to 5), for example, the dispersant may be used in an amount of 0.1, 0.2, 0.3, 0.4, or 0.5 parts by weight, etc., and the cellulose nanocrystals may be used in an amount of 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, or 5 parts by weight, etc., based on 10 parts by weight of the polyvinyl alcohol, and the inventors have found that, if the dispersant is used in an amount too small, it is not favorable for sufficient mixing of the polyvinyl alcohol and the cellulose nanocrystals; if the dosage of the cellulose nanocrystals is too small, the effect of improving the hydrogen bond concentration in the polymer is not obvious, and the damping performance of the sound insulation material is not favorably improved, and if the dosage of the cellulose nanocrystals is too large, the cellulose nanocrystals are easy to agglomerate, the dispersibility of the cellulose nanocrystals is poor, and the uniform dispersion and reaction of the cellulose nanocrystals and polyvinyl alcohol are difficult to realize, so that the micro-nano characteristics of the cellulose nanocrystals are difficult to realize, the mechanical performance of the polymer is easy to influence, and the damping performance of the material is difficult to improve. According to the invention, the uniform modification of the polyvinyl alcohol by the cellulose nanocrystals and the improvement of the damping performance of the material are more favorably realized by controlling the dosage ranges of the dispersing agent and the cellulose nanocrystals.
According to another embodiment of the present invention, the temperature of the mixing reaction may be 50 to 70 ℃, for example, 55 ℃, 60 ℃ or 65 ℃, and the time may be 0.5 to 5 hours, for example, 1 hour, 2 hours, 3 hours, 4 hours or 5 hours, and the inventors found that under the reaction conditions, not only the reaction is milder and controllable, but also the polyvinyl alcohol and the cellulose nanocrystals can be fully reacted, and uniformly modified polyvinyl alcohol can be obtained.
S300, mixing the modified polyvinyl alcohol with the polymer and performing injection molding to obtain the sound insulation material
According to the embodiment of the present invention, the shape of the sound insulation material is not particularly limited, and those skilled in the art can select the sound insulation material according to actual needs, for example, the sound insulation material may have a honeycomb network structure, so that on one hand, the damping characteristic of the material can be improved by utilizing the mutual friction between the chain segments in the sound insulation material molecules, and on the other hand, the honeycomb network structure can be utilized to effectively control the air vibration, reduce the propagation of noise, and achieve the light weight effect of the sound insulation material.
According to a specific embodiment of the present invention, the kind of the polymer used for preparing the sound-proofing material in the present invention is not particularly limited, and can be selected by those skilled in the art according to actual needs, for example, the polymer can be at least one selected from polypropylene, polyvinyl chloride and polyurethane, thereby ensuring the damping performance of the sound-proofing material and improving the mechanical strength and thermal stability of the damping material.
According to another embodiment of the present invention, the proportion of the modified polyvinyl alcohol in the sound insulation material may be 5 to 50 wt%, for example, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, or 50 wt%, etc., and the inventors have found that if the proportion of the modified polyvinyl alcohol in the sound insulation material is too small, the improvement of the damping performance of the sound insulation material is not significant, and if the proportion of the modified polyvinyl alcohol in the sound insulation material is too large, the moldability, mechanical strength, and temperature resistance of the sound insulation material are easily affected, which greatly limits the practical application of the sound insulation material. The sound insulation material can simultaneously give consideration to the formability, the mechanical property and the damping property of the sound insulation material by controlling the proportion of the modified polyvinyl alcohol in the sound insulation material, so that the sound insulation material can be widely applied to various noise reduction devices, such as automobile materials.
According to another embodiment of the present invention, the honeycomb (top view) may be a regular hexagon, and the thickness of the honeycomb may be 5-100 mm, such as 10mm, 20mm, 30mm, 40mm, 50mm, 60mm, 70mm, 80mm, or 90 mm; the length of the bevel edge of the bee core can be 2-50 mm, for example, 5mm, 10mm, 15mm, 20mm, 25mm, 30mm, 35mm, 40mm, 45mm or 50 mm; the thickness of the bee core wall can be 0.2-4 mm, for example, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm or 4 mm; the thickness of the honeycomb panel may be 0.5 to 10mm, and for example, may be 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, or 9 mm. In fact, the thickness of the honeycomb is the total height of the honeycomb core and the thickness of the panel, the side length of the inclined honeycomb core is the side length of a regular hexagon, the wall thickness of the honeycomb core is the thickness of the side edge of the hexagon, the thickness of the panel of the honeycomb is the thickness of the upper surface and the lower surface of the honeycomb, and the thickness of the honeycomb, the side length of the inclined honeycomb core and the wall thickness of the honeycomb core have larger influence on the damping performance of the sound insulation material, wherein the length of the inclined honeycomb edge is lower, which is equivalent to that the density of the honeycomb is higher, and is more beneficial to improving the damping performance of the sound insulation material; the larger the thickness of the honeycomb is, the larger the thickness of the sound insulation material is, and the larger the wall thickness of the honeycomb core is, the larger the thickness of each single honeycomb core is, which is beneficial to improving the damping performance of the material. According to the invention, the size range of the honeycomb sound insulation material is controlled, so that the sound insulation effect of the sound insulation material is improved.
In summary, the method for preparing the sound insulation material according to the above embodiment of the present invention has at least the following beneficial effects: 1) by carrying out oxidative degradation on cellulose under an alkaline condition, the problem that hydrogen bonds in the cellulose are broken due to an acidic oxidation condition, and the modification effect of cellulose nanocrystals on polyvinyl alcohol is further reduced can be avoided; 2) the grafting concentration of the cellulose nanocrystals in the sound insulation material can be flexibly adjusted by adjusting the ratio of the cellulose nanocrystals to the polyvinyl alcohol and the ratio of the modified polyvinyl alcohol to the polymer, and the hydrogen bond density of polymer molecules is improved, so that excellent sound insulation performance is obtained; 3) the sound insulation material with an expected structure, such as a honeycomb network structure, can be obtained according to injection molding, so that the effects of improving the sound insulation performance and lightening the material are achieved; 4) the prepared sound insulation material has the advantages of high strength, good thermal stability, low expansion coefficient, good sound insulation performance and the like, can meet the requirements of material use performance and obtain better damping characteristic, thereby obtaining better NVH silent performance and having wide application prospect in the aspects of noise reduction in the field of automobiles.
According to a second aspect of the present invention, a sound insulating material is provided. According to an embodiment of the present invention, the soundproof material is manufactured by the method for manufacturing the soundproof material described above. Compared with the prior art, the sound insulation material has higher hydrogen bond concentration, can greatly increase the mutual friction among the chain segments in the polymer molecules through the breakage and recombination of the hydrogen bonds in the using process, accelerates the dissipation of external mechanical energy, and obviously improves the damping performance of the sound insulation material; in addition, the sound insulation material also has the advantages of high strength, good thermal stability, low expansion coefficient, good sound insulation performance and the like, can meet the requirements of material use performance and simultaneously obtain better damping characteristics, particularly can further improve the sound insulation performance and achieve the effect of light weight when the sound insulation material has a honeycomb network structure, and can be widely applied to the field of automobiles as the sound insulation material for vehicles. It should be noted that the features and effects described for the above-mentioned method for preparing the sound insulation material are also applicable to the sound insulation material, and are not described in detail herein.
According to a third aspect of the present invention, a vehicle is provided. According to an embodiment of the present invention, the vehicle includes the above-described soundproof material or the soundproof material produced by the above-described method of producing a soundproof material. In the prior art, the noise generated by the vehicle during road running and engine working is less spread, and the noise transmission method has very important significance for reducing traffic noise, urban noise and various hazards generated by noise. It should be noted that the features and effects described for the sound-insulating material and the method for preparing the sound-insulating material are also applicable to the vehicle, and are not described in detail herein.
The following examples are illustrative only and are not to be construed as limiting the invention. The examples, where specific techniques or conditions are not indicated, are to be construed according to the techniques or conditions described in the literature in the art or according to the product specifications. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available.
Example 1
1. Cellulose nanocrystal preparation
100g of the 3% strength by weight dissociated fiber slurry was charged into a 300ml vessel, 0.1g of NaBr and 0.01g of TEMPO reagent were added, the reaction was stirred under magnetic stirring, 4ml of NaClO solution was further added, and the pH of the reaction solution was continuously adjusted to 10.0 with NaOH. The reaction temperature is maintained at 20 ℃ and the reaction time is 12 h. And after the reaction is finished, performing membrane filtration on the reaction product, and washing the reaction product to be neutral to obtain the cellulose nanocrystal.
2. Cellulose nanocrystal modified PVA (polyvinyl alcohol)
Adding 10g of polyvinyl alcohol into a three-neck flask provided with a stirring and refluxing device, adding 200ml of water and 0.2g of p-toluenesulfonic acid, stirring, heating to 90 ℃, fully dispersing and dissolving, and reacting for 1h under heat preservation to obtain a polyvinyl alcohol aqueous solution. And cooling to 50-70 ℃, accelerating the stirring speed, adding 2g of cellulose nanocrystals, and continuing to perform heat preservation reaction for 2 hours to obtain the cellulose nanocrystal modified polyvinyl alcohol.
3. Preparation of modified polyvinyl alcohol honeycomb material
Mixing and stirring the prepared modified polyvinyl alcohol honeycomb material and a polypropylene (PP) material for 2 hours at a mixing speed of 300 r/min; and (3) performing injection molding on the mixed and stirred material at the temperature of 110-130 ℃, wherein the honeycomb is a regular hexagon honeycomb, the thickness of the honeycomb is 10mm, the side length of a honeycomb core slant is 10mm, the wall thickness of the honeycomb core is 0.5mm, and the thickness of a honeycomb panel is 3 mm. Wherein the mass ratio of the modified polyvinyl alcohol material is 30%.
Example 2
The difference from example 1 is that: in step 2, 1.5g of cellulose nanocrystals are added; the adding mass percentage of the modified PVA material in the step 3 is 25%.
Example 3
The difference from example 1 is that: in the step 3, the adding mass percent of the modified PVA material is 15%, and the length of the inclined side of the honeycomb core is 8 mm.
Example 4
The difference from example 1 is that: in the step 3, the length of the inclined side of the honeycomb core is 8mm, and the thickness of the panel is 2 mm.
Comparative example
The honeycomb was prepared as in example 1, except that no PVA modifying material was added.
The sound-deadening and noise-reducing performances of the sound-insulating materials prepared in examples 1 to 4 and comparative example 1 were evaluated, and the test results are shown in table 1, specifically according to GB/T19889.3. It can be seen from table 1 that the sound insulation performance is deteriorated due to the reduction of the addition amount of the cellulose nanocrystals in the modified polyvinyl alcohol and the addition amount of the modified PVA material in the sound insulation material, and the reduction of the length of the beveled edge of the honeycomb core can compensate for the negative effect of the reduction of the thickness of the panel on the sound insulation and noise reduction effect to a certain extent.
TABLE 1 comparison of the Performance of examples 1-4 and comparative example 1
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.
Claims (10)
1. A method of making an acoustical insulation comprising:
(1) carrying out oxidative degradation on cellulose under alkaline conditions so as to obtain cellulose nanocrystals;
(2) mixing and reacting the cellulose nanocrystals, polyvinyl alcohol, a dispersing agent and water to obtain cellulose nanocrystal modified polyvinyl alcohol;
(3) mixing the modified polyvinyl alcohol with a polymer and injection molding to obtain the sound insulating material.
2. The method of claim 1, wherein step (1) comprises:
dissociating the cellulose to obtain a dissociated fiber slurry;
mixing the fiber slurry with sodium bromide, tetramethylpiperidine and sodium hypochlorite to obtain a reaction solution;
and adjusting the pH value of the reaction solution to be alkaline to carry out oxidative degradation so as to obtain the cellulose nanocrystals.
3. The method of claim 2, wherein step (1) satisfies at least one of the following conditions:
the mass concentration of the fiber slurry is 1-5 wt%, the sodium hypochlorite is a sodium hypochlorite solution with the concentration of 85-95 wt%, and the mass ratio of the fiber slurry to the sodium bromide to the tetramethyl piperidine is 100: (0.05-0.3): (0.005-0.1), wherein the solid-to-liquid ratio of the fiber pulp to the sodium hypochlorite solution is 100 g: (2-5) mL;
controlling the pH value of the reaction liquid to be 9-11 all the time in the oxidative degradation process;
the temperature of the oxidative degradation is 0-20 ℃, and the time is 6-48 h;
the size of the cellulose nanocrystal is 0.3-2 mu m;
the cellulose nanocrystal comprises 25-35% of carboxyl.
4. The method of claim 1 or 3, wherein step (2) comprises:
mixing the polyvinyl alcohol with a dispersant and water to obtain a polyvinyl alcohol solution;
and mixing and reacting the cellulose nanocrystals with the polyvinyl alcohol solution to obtain cellulose nanocrystal modified polyvinyl alcohol.
5. The method of claim 4, wherein step (2) satisfies at least one of the following conditions:
the mass ratio of the polyvinyl alcohol to the dispersing agent to the cellulose nanocrystals is 10: (0.1-0.5): (0.5 to 5);
the temperature of the mixing reaction is 50-70 ℃, and the time is 0.5-5 h;
the dispersant is at least one selected from toluene sulfonic acid, sodium benzene sulfonate, sodium dodecyl sulfonate, sodium sulfosuccinate and dodecyl pyridine.
6. The method according to claim 1 or 5, wherein step (3) satisfies at least one of the following conditions:
the polymer is at least one selected from polypropylene, polyvinyl chloride and polyurethane;
the proportion of the modified polyvinyl alcohol in the sound insulation material is 5-50 wt%;
the sound insulation material is of a honeycomb net structure.
7. The method of claim 6, wherein the honeycomb is a regular hexagon.
8. The method of claim 7, wherein the honeycomb has a thickness of 5 to 100mm, a core diagonal length of 2 to 50mm, a core wall thickness of 0.2 to 4mm, and a honeycomb panel thickness of 0.5 to 10 mm.
9. A sound insulating material produced by the method according to any one of claims 1 to 8.
10. A vehicle comprising the sound-insulating material according to claim 9 or the sound-insulating material produced by the method according to any one of claims 1 to 8.
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Application publication date: 20211126 |