Sound insulation bamboo powder magnesium sulfide composite material and preparation method thereof

Abstract

The application discloses a sound insulation bamboo powder magnesium oxysulfate cement composite material and a preparation method, and belongs to the technical field of building materials. The composite material takes magnesium oxysulfate cement as a matrix, and is mixed with alkali-treated bamboo powder and rubber powder as functional components. By alkali treatment of the bamboo powder, more active hydroxyl groups are exposed on the surface of the bamboo powder, the chemical bonding force between the bamboo powder and the cement matrix is enhanced, the interface compatibility is improved, the bamboo powder surface is roughened, and then a mechanical interlocking structure is formed with the rubber powder, and the uniform dispersion and synergistic effect of the two in the cement are promoted. On the basis of improving the mechanical properties of the composite material, the porous sound wave absorption characteristics of the alkali-treated bamboo powder and the viscoelastic damping effect of the rubber powder are utilized to construct a multi-scale sound wave dissipation system, so that the sound insulation performance of the material in the full frequency range is optimized.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, and in particular to a sound-insulating bamboo powder magnesium oxysulfate composite material and its preparation method. Background Technology

[0002] In the built environment, sound insulation performance is one of the important indicators for evaluating the functionality of building materials. Traditional sound insulation materials such as gypsum board and concrete, while possessing certain sound insulation effects, generally suffer from high density, poor toughness, inconvenient construction, and insufficient environmental performance, making it difficult to meet the demands of modern buildings for lightweight, efficient, and green building materials. Magnesium oxysulfate cement, as a new type of cementitious material, has received widespread attention in recent years due to its advantages such as lightweight, high strength, fire resistance, and environmental friendliness. However, the relatively weak sound insulation performance of magnesium oxysulfate cement limits its application in scenarios with high sound insulation requirements. Therefore, to further optimize the performance of magnesium oxysulfate cement, it is necessary to simultaneously consider its sound insulation performance, mechanical properties, and environmental friendliness. Summary of the Invention

[0003] To further optimize the performance of magnesium oxysulfate cement, this invention introduces bamboo powder and rubber powder to provide a magnesium oxysulfate cement that combines excellent sound insulation performance, good mechanical properties, and environmental friendliness.

[0004] The present invention provides a sound-insulating bamboo powder magnesium oxysulfate composite material and its preparation method, which adopts the following technical solution:

[0005] A sound-insulating bamboo powder magnesium sulfate composite material is composed of the following raw materials in parts by weight: 100-130 parts of lightly calcined magnesium oxide, 30-40 parts of magnesium sulfate heptahydrate, 20-40 parts of water, 3-7 parts of alkali-treated bamboo powder, 1-5 parts of rubber powder, and 1-2 parts of additives.

[0006] Preferably, the bamboo powder is nan bamboo powder.

[0007] Preferably, the particle size of the bamboo powder is 50-70 mesh and the aspect ratio is 100-180.

[0008] It should be noted that, due to the large aspect ratio of its fibers, bamboo powder is more likely to interlock within the matrix, forming a more effective three-dimensional network structure. This improves stress transfer efficiency and achieves superior toughening and crack resistance. Simultaneously, its high density and porous structure give bamboo powder superior sound insulation performance compared to other bamboo powder materials. This invention also limits the particle size of the bamboo powder because excessively large particles weaken its interfacial bonding with the matrix, reducing the material's toughness and impact strength, and also causing a decrease in sound insulation performance due to the formation of larger pores. Conversely, excessively small particles easily cause bamboo powder agglomeration, weakening the sound insulation effect.

[0009] Preferably, the rubber powder is waste tire rubber powder with a particle size of 140-160 mesh.

[0010] It should be noted that the particle size of the rubber powder is limited in this invention because if the particle size is too large, it will weaken the interfacial bonding between the rubber powder and the matrix, and sound waves will be more easily reflected and transmitted at the interface between the two, thereby reducing the sound insulation performance; while if the particle size is too small, it will cause the rubber powder to lose its elasticity and its damping performance to decrease, which will have an adverse effect on the sound insulation effect.

[0011] Preferably, the additive is citric acid.

[0012] The above-mentioned method for preparing a sound-insulating bamboo powder magnesium oxysulfate composite material includes the following steps:

[0013] (1) Bamboo powder is treated with alkali to expose more active hydroxyl groups on its surface and to achieve surface roughening and pore structure optimization;

[0014] (2) Mix magnesium sulfate heptahydrate, additives and water, and stir until completely dissolved to obtain solution A;

[0015] (3) Add lightly calcined magnesium oxide, alkali-treated bamboo powder and rubber powder to a mixer for premixing, so that the alkali-treated bamboo powder and rubber powder form a mechanical interlock. Then add solution A and continue stirring. Utilize the chemical bonding effect between the surface active hydroxyl groups of the alkali-treated bamboo powder and the cement matrix to promote the uniform dispersion of bamboo powder and rubber powder in cement, and obtain cement slurry.

[0016] (4) The cement slurry is injected into the mold, vibrated to release air, and then left to stand to form. After demolding, it is cured to obtain the sound-insulating bamboo powder sulfur-oxygen magnesium cement composite material.

[0017] Preferably, the alkali treatment in step (1) involves soaking the bamboo powder in a sodium hydroxide aqueous solution with a mass concentration of 1%-5% for 2-3 hours.

[0018] It should be noted that alkali treatment can expose the active hydroxyl groups on the surface of bamboo powder, enhance its chemical bonding with the cement matrix, and improve interfacial compatibility; at the same time, it roughens the surface of bamboo powder, forms a mechanical interlock with rubber powder, promotes the uniform dispersion of the two in cement, and works together to play the roles of crack resistance, toughening and sound insulation.

[0019] It should be noted that alkali treatment can also optimize the pore structure of bamboo powder, further enhancing its absorption and attenuation performance of sound waves.

[0020] Preferably, the stirring time in step (3) is 5-7 minutes.

[0021] Preferably, the maintenance conditions in step (4) are: temperature 25-40℃, relative humidity 50-65%, and maintenance time 18-28 days.

[0022] Preferably, the application of the above-mentioned magnesium oxysulfate cement in the field of building materials is also within the scope of protection of this invention.

[0023] The beneficial effects of this invention are as follows:

[0024] (1) This invention selects bamboo powder with high aspect ratio, high density and porous structure as a reinforcing material. Alkali treatment is used to expose more active hydroxyl groups on its surface and roughen the surface. The introduction of surface active hydroxyl groups enhances the chemical bonding force between bamboo powder and cement matrix, improves their interfacial compatibility, and thus improves the dispersibility of bamboo powder in cement matrix. At the same time, the roughened surface structure of bamboo powder caused by alkali treatment forms a mechanical interlocking effect with rubber powder, further enhancing the synergistic dispersion effect of the two in cement matrix. This helps bamboo powder and rubber powder to jointly play the roles of crack resistance, toughening and sound insulation, thereby improving the comprehensive performance of composite materials.

[0025] (2) The porous structure of bamboo powder endows it with good absorption and attenuation performance of mid-to-high frequency sound waves. After alkali treatment, its pore structure is further optimized and the number of micropores increases, which helps more sound waves to enter the interior of the material and convert sound energy into heat energy or mechanical energy through friction. At the same time, rubber powder, with its high damping elasticity and uniform dispersion in the matrix, forms elastic contact points with the cement matrix, enhancing the attenuation effect of mid-to-low frequency sound waves. The synergistic effect of bamboo powder and rubber powder constructs a multi-scale sound wave dissipation structure, realizing an overall improvement in sound insulation performance across the entire frequency range from low to high frequencies.

[0026] (3) On the basis of ensuring the mechanical properties of magnesium oxide cement, this invention realizes the efficient resource utilization of waste bamboo powder and waste tire rubber particles, and has the environmental protection advantages of "double carbon reduction and solid waste utilization", which is in line with the strategic direction of sustainable development of green building materials. Detailed Implementation

[0027] Example 1

[0028] A sound-insulating bamboo powder magnesium sulfate composite material, the raw materials by weight include 120 parts of lightly calcined magnesium oxide, 35 parts of magnesium sulfate heptahydrate, 35 parts of water, 5 parts of alkali-treated bamboo powder (nan bamboo), 1 part of rubber powder, and 2 parts of citric acid.

[0029] A method for preparing a sound-insulating magnesium oxysulfate composite material includes the following steps:

[0030] (1) Bamboo powder was pretreated in a 3% sodium hydroxide aqueous solution for 2 hours. After treatment, it was dried at 80°C for later use.

[0031] (2) Mix magnesium sulfate heptahydrate, citric acid and water, and stir until completely dissolved to obtain solution A;

[0032] (3) Add lightly calcined magnesium oxide, alkali-treated bamboo powder and rubber powder to a mixer and stir until evenly dispersed. Then add solution A and continue stirring for 6 minutes to obtain cement slurry.

[0033] (4) Inject the mixed slurry into the mold, vibrate to remove air, and let it stand to form. After demolding, cure for 28 days at a temperature of 25-40℃ and a relative humidity of 50-65% to obtain the sound-insulating bamboo powder sulfur-oxygen magnesium cement composite material.

[0034] Example 2

[0035] A sound-insulating bamboo powder magnesium sulfate composite material, the raw materials by weight include 120 parts of lightly calcined magnesium oxide, 35 parts of magnesium sulfate heptahydrate, 35 parts of water, 5 parts of alkali-treated bamboo powder (nan bamboo), 3 parts of rubber powder, 2 parts of citric acid, and the others are the same as in Example 1.

[0036] Example 3

[0037] A sound-insulating bamboo powder magnesium sulfate composite material, the raw materials by weight include 120 parts of lightly calcined magnesium oxide, 35 parts of magnesium sulfate heptahydrate, 35 parts of water, 5 parts of alkali-treated bamboo powder (nan bamboo), 5 parts of rubber powder, 2 parts of citric acid, and the other components are the same as in Example 1.

[0038] Example 4

[0039] A sound-insulating bamboo powder magnesium sulfate composite material, the raw materials by weight include 120 parts of lightly calcined magnesium oxide, 35 parts of magnesium sulfate heptahydrate, 35 parts of water, 3 parts of alkali-treated bamboo powder (nan bamboo), 3 parts of rubber powder, 2 parts of citric acid, and the others are the same as in Example 1.

[0040] Example 5

[0041] A sound-insulating bamboo powder magnesium sulfate composite material, the raw materials by weight include 120 parts of lightly calcined magnesium oxide, 35 parts of magnesium sulfate heptahydrate, 35 parts of water, 7 parts of alkali-treated bamboo powder (nan bamboo), 3 parts of rubber powder, 2 parts of citric acid, and the others are the same as in Example 1.

[0042] Comparative Example 1

[0043] The bamboo powder is untreated moso bamboo powder, and the rest is the same as in Example 2.

[0044] Comparative Example 2

[0045] The bamboo powder is alkali-treated hemp bamboo powder, and the rest is the same as in Example 2.

[0046] Comparative Example 3

[0047] The bamboo powder is alkali-treated bamboo powder, and the rest is the same as in Example 2.

[0048] Comparative Example 4

[0049] The bamboo powder without alkali treatment is the same as in Example 2.

[0050] Comparative Example 5

[0051] No rubber powder was added; otherwise, it was the same as in Example 2.

[0052] Performance testing methods: Strength testing is conducted in accordance with GB / T 17671-1999 "Test Method for Strength of Cement Mortar"; Ductility index testing is conducted in accordance with GB / T 15231-2008 "Test Method for Performance of Glass Fiber Reinforced Cement"; Sound insulation testing is conducted in accordance with GB / T 19889 "Measurement of Sound Insulation of Buildings and Building Components".

[0053] Table 1 Performance test results of magnesium oxysulfate cement prepared in Examples 1-5 and Comparative Examples 1-5

[0054]

[0055] The results of Examples 1-5 show that the present invention, by using alkali-treated bamboo powder and rubber powder in combination, effectively balances the mechanical and sound insulation properties of the materials, providing a feasible approach for the high-value-added resource utilization of bamboo and waste rubber. The results of Comparative Examples 2 and 3 indicate that bamboo fiber with a high aspect ratio has a more significant reinforcing effect and sound insulation performance, making it a superior choice. A comparison between Example 2 and Comparative Example 1 shows that alkali treatment can effectively activate the surface of bamboo powder, enhancing its interfacial bonding with the cement matrix, thereby achieving the strengthening and toughening of the composite material. Furthermore, the decrease in sound insulation performance in Comparative Example 1 indicates that alkali treatment helps optimize the pore structure of bamboo powder, enhancing its ability to absorb and attenuate sound waves. Simultaneously, alkali-treated bamboo powder can also promote the formation of a mechanically interlocking structure with rubber powder, improving their dispersion in the matrix and synergistically enhancing crack resistance, toughening, and sound insulation effects.

[0056] In Comparative Example 4, without the addition of alkali-treated bamboo powder, the material's strength and ductility were significantly reduced due to the lack of a rigid supporting framework, resulting in a corresponding decrease in sound insulation performance. In Comparative Example 5, without the addition of rubber powder, the composite material's sound insulation performance was significantly weakened due to the absence of its damping effect, and its mechanical properties decreased simultaneously. These results further demonstrate that bamboo powder and rubber powder have a synergistic effect in terms of mechanical reinforcement and sound insulation function, and neither can be dispensed with.

[0057] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A sound-insulating bamboo powder magnesium oxysulfate cement composite material, characterized in that, It is composed of the following raw materials in parts by weight: 100-130 parts of lightly calcined magnesium oxide, 30-40 parts of magnesium sulfate heptahydrate, 20-40 parts of water, 3-7 parts of alkali-treated bamboo powder, 1-5 parts of rubber powder, and 1-2 parts of additives.

2. The sound-insulating bamboo powder magnesium oxysulfate cement composite material according to claim 1, characterized in that: The bamboo powder is Nan bamboo powder.

3. The sound-insulating bamboo powder magnesium oxysulfate cement composite material according to claim 2, characterized in that: The particle size of the bamboo powder is 50-70 mesh, and the aspect ratio is 100-180.

4. The sound-insulating bamboo powder magnesium oxysulfate cement composite material according to claim 1, characterized in that: The rubber powder is waste tire rubber powder with a particle size of 140-160 mesh.

5. The sound-insulating bamboo powder magnesium oxysulfate cement composite material according to claim 1, characterized in that: The additive is citric acid.

6. A method for preparing a sound-insulating bamboo powder magnesium oxysulfate cement composite material according to any one of claims 1-5, characterized in that, Includes the following steps: (1) Bamboo powder is treated with alkali to expose more active hydroxyl groups on its surface and to achieve surface roughening and pore structure optimization; (2) Mix magnesium sulfate heptahydrate, additives and water, and stir until completely dissolved to obtain solution A; (3) Add lightly calcined magnesium oxide, alkali-treated bamboo powder and rubber powder to a mixer for premixing, so that the alkali-treated bamboo powder and rubber powder form a mechanical interlock. Then add solution A and continue stirring. Utilize the chemical bonding effect between the surface active hydroxyl groups of the alkali-treated bamboo powder and the cement matrix to promote the uniform dispersion of bamboo powder and rubber powder in cement, and obtain cement slurry. (4) The cement slurry is injected into the mold, vibrated to release air, and then left to stand to form. After demolding, it is cured to obtain the sound-insulating bamboo powder sulfur-oxygen magnesium cement composite material.

7. The preparation method of the sound-insulating bamboo powder magnesium oxysulfate cement composite material according to claim 6, characterized in that: The alkali treatment in step (1) involves soaking the bamboo powder in a sodium hydroxide aqueous solution with a mass concentration of 1%-5% for 2-3 hours.

8. The preparation method of the sound-insulating bamboo powder magnesium oxysulfate cement composite material according to claim 6, characterized in that: The stirring time in step (3) is 5-7 minutes.

9. The preparation method of the sound-insulating bamboo powder magnesium oxysulfate cement composite material according to claim 6, characterized in that, The maintenance conditions described in step (4) are: temperature 25-40℃, relative humidity 50-65%, and maintenance time 18-28 days.

10. The application of the sound-insulating bamboo powder magnesium oxysulfate cement composite material as described in any one of claims 1-5 in the field of building materials.

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