Modified magnesium oxysulfate inorganic binder and preparation method therefor, and inorganic-bonded bamboo particle board
By combining modified magnesium oxysulfate inorganic adhesive with bamboo chips, the problem of insufficient utilization of bamboo chip waste is solved, and bamboo chip boards with excellent mechanical and environmental performance are prepared, which are suitable for building, furniture and decorative materials.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- SHANDONG JIANZHU UNIV
- Filing Date
- 2025-10-14
- Publication Date
- 2026-07-23
AI Technical Summary
The waste generated during the processing of bamboo shavings is not effectively utilized, and traditional organic adhesives have problems such as poor environmental adaptability, weak bonding force, and insufficient compressive and flexural strength.
A bamboo chip board with excellent mechanical properties was prepared by combining modified magnesium oxysulfate inorganic adhesive with bamboo chips and adding modifiers and stabilizers such as citric acid, silica fume, silica sol, lithium silicate, sodium tripolyphosphate, nano-silica, amphibole powder and multi-walled carbon nanotubes to improve the adhesive strength, structural stability and fire resistance of the adhesive.
The prepared modified magnesium oxysulfate inorganic adhesive bamboo chip board has excellent mechanical properties, fire resistance and environmental protection properties, reduces resource waste and environmental pollution, and is suitable for the fields of building, furniture and decoration materials.
Smart Images
Figure CN2025127576_23072026_PF_FP_ABST
Abstract
Description
A modified magnesium oxysulfate inorganic adhesive and its preparation method, and bamboo chipboard. Technical Field
[0001] This invention belongs to the field of solid waste treatment technology, specifically relating to a modified magnesium oxysulfate inorganic adhesive, its preparation method, and bamboo chipboard. Background Technology
[0002] Bamboo is a green and renewable resource, widely used in construction, furniture, papermaking, and textiles due to its short growth cycle, high strength, and good mechanical properties. However, bamboo processing generates a large amount of waste bamboo shavings, typically accounting for 5%-15% of the total weight of bamboo. If these bamboo shavings are not effectively utilized, they are often discarded or burned, resulting in resource waste and environmental pollution.
[0003] Traditional bamboo shavings are mostly processed using organic adhesives such as "three-aldehyde glue" (urea-formaldehyde resin, phenol-formaldehyde resin, melamine-formaldehyde resin). However, these materials have poor environmental adaptability and pose problems such as formaldehyde release, environmental pollution, and fire hazards. Furthermore, as a natural organic fiber, bamboo shavings contain hydroxyl (-OH) groups and other hydrophilic functional groups on their surface, which makes their bonding strength with inorganic adhesives relatively weak. Structures prepared using bamboo shavings and inorganic adhesives have poor compressive and flexural strength, and also poor toughness. Summary of the Invention
[0004] To address the above technical problems, this invention provides a modified magnesium oxysulfate inorganic adhesive, its preparation method, and a bamboo chip board. By combining the modified magnesium oxysulfate inorganic adhesive with waste bamboo chips, an inorganic adhesive bamboo chip board with excellent mechanical properties, fire resistance, environmental performance, and water resistance is prepared.
[0005] To achieve the above objectives, the present invention is implemented through the following technical solution:
[0006] In a first aspect, the present invention provides a modified magnesium sulfate inorganic adhesive, which, by weight, is composed of the following components: 100 parts of lightly calcined magnesium oxide, 20-60 parts of magnesium sulfate heptahydrate, 50-85 parts of water, 1.1-17 parts of modifier, and 1.8-5.3 parts of stabilizer.
[0007] The modifier comprises: 0.2-3 parts citric acid, 0.5-8 parts silica fume, 0.1-3 parts silica sol, 0.2-2 parts lithium silicate, 0.1-1 parts sodium tripolyphosphate, and 0.5-5 parts nano-silicon;
[0008] The stabilizer comprises: 1-3.5 parts of amphibole powder, 0.5-3 parts of sodium silicate, and 0.3-0.8 parts of multi-walled carbon nanotubes.
[0009] This invention primarily uses lightly calcined magnesium oxide and magnesium sulfate heptahydrate as base materials, which undergo a chemical reaction to generate magnesium oxysulfate inorganic adhesive, exhibiting good durability and environmental friendliness. However, magnesium oxysulfate has drawbacks such as low strength and poor bonding performance, requiring the addition of modifiers and stabilizers to improve its adhesion to bamboo chips and overall mechanical properties. Furthermore, the addition of lightly calcined magnesium oxide can further enhance the refractory properties of the adhesive.
[0010] Among the modifiers, citric acid can slow down the coagulation rate of inorganic adhesives, improve the hydration process of magnesium oxysulfate inorganic adhesives, and effectively improve the mechanical properties of the colloid; silica fume can improve the microstructure of hydration products and improve the compressive strength and toughness of the colloid; silica sol, as a water-soluble silicate colloid, can form a dense three-dimensional network structure in magnesium oxysulfate inorganic adhesives, enhancing the structural stability of the colloid; lithium silicate can act as a reactive silicon source in magnesium oxysulfate inorganic adhesives, enhancing the hardness and corrosion resistance of the colloid; sodium tripolyphosphate can improve the fluidity and stability of the colloid, prevent the precipitation or exudation of components, and enhance the overall structure of the colloid. Among them, phosphate ions react with hydroxyl groups and cellulose on the surface of bamboo chips, promoting the physical adsorption and chemical bonding between inorganic adhesives and bamboo chips, and improving the adhesion between the two; nano-silicon particles have a high specific surface area and can undergo strong chemical reactions with other components (such as magnesium oxide and magnesium sulfate), improving the microstructure of the colloid, forming good interfacial contact with the surface of bamboo chips, and further improving the adhesion performance between the colloid and bamboo chips.
[0011] In the stabilizer, the layered structure of amphibole powder can improve the mechanical strength of the inorganic adhesive and reduce cracks generated during the hardening process, thus contributing to the improvement of the stability and durability of the modified inorganic adhesive. The introduction of amphibole powder can also improve the wettability of the colloid and promote good adhesion with bamboo chips. The aqueous solution of sodium silicate, commonly known as water glass, can effectively reduce the dispersibility of the cementitious material in water, improve the waterproof performance of the inorganic adhesive, and enhance the long-term stability of the adhesive strength. The surface of multi-walled carbon nanotubes has abundant hydrophilic and hydrophobic functional groups, which can improve the compatibility between the colloid and waste bamboo chips, thereby enhancing the adhesive ability of the colloid. At the same time, multi-walled carbon nanotubes have excellent thermal stability and thermochemical properties, which can improve the fire resistance and corrosion resistance of magnesium oxysulfate inorganic adhesive, and prevent interfacial delamination between bamboo chips and inorganic adhesive caused by environmental factors, thereby improving the durability of inorganic adhesive bamboo chip boards.
[0012] In some embodiments, the modified magnesium sulfate inorganic adhesive, by weight, comprises the following components: 100 parts of lightly calcined magnesium oxide, 20-40 parts of magnesium sulfate heptahydrate, 60-85 parts of water, 4-15 parts of modifier, and 3-5 parts of stabilizer.
[0013] Preferably, the modifier comprises: 1-3 parts citric acid, 0.5-5 parts silica fume, 0.3-2 parts silica sol, 0.2-1 parts lithium silicate, 0.3-1 parts sodium tripolyphosphate, and 0.5-3 parts nano-silicon.
[0014] Preferably, the stabilizer comprises: 1.5 to 3 parts of amphibole powder, 1 to 2 parts of sodium silicate, and 0.3 to 0.5 parts of multi-walled carbon nanotubes.
[0015] Secondly, the present invention provides a method for preparing the modified magnesium sulfate inorganic adhesive, comprising the following steps: dissolving magnesium sulfate heptahydrate in water to obtain a magnesium sulfate solution;
[0016] Then, silica sol, lithium silicate, sodium silicate, citric acid, sodium tripolyphosphate, nano-silicon, amphibole powder and multi-walled carbon nanotubes were added to magnesium sulfate aqueous solution in proportion. After stirring and mixing, lightly calcined magnesium oxide and silica fume were added, mixed and stirred continuously. After the reaction was completed, modified magnesium sulfate inorganic adhesive was obtained.
[0017] Because the reaction between light-burned magnesium oxide and magnesium sulfate heptahydrate is rapid, without adjusting the order of component addition and adding a retarder, the inorganic colloid will have an excessively short setting time, making it difficult to apply in practical engineering. In this invention, light-burned magnesium oxide and magnesium sulfate heptahydrate are mixed stepwise, and the magnesium sulfate heptahydrate and the retarder are ensured to be uniformly mixed before the two are fully combined. Furthermore, silica fume, as a modifier, can improve the microstructure of the hydration products during the chemical reaction between light-burned magnesium oxide and magnesium sulfate heptahydrate, further optimizing the mechanical properties and structural stability of the colloid.
[0018] Thirdly, the present invention provides a bamboo chip board, which is prepared by mixing the modified magnesium oxysulfate inorganic adhesive and bamboo chips in a mass ratio of 6-8:2-4.
[0019] In some embodiments, the method for preparing the bamboo chip board is as follows: bamboo chips generated during bamboo processing, and dead or soon-to-be-dead bamboo are chipped into bamboo chips.
[0020] After drying the bamboo shavings, they are mixed with the modified magnesium oxysulfate inorganic adhesive at a mass ratio of 2-4:6-8. The mixture is poured into a mold, pressed into shape, and cured to obtain a bamboo shaving board.
[0021] Preferably, the bamboo shavings are sieved, and the diameter of the sieved bamboo shavings does not exceed 2 mm and the length does not exceed 10 mm.
[0022] Preferably, the moisture content of the dried bamboo shavings is less than 10%.
[0023] Preferably, the maintenance conditions are 20±3℃ and 60% RH relative humidity.
[0024] More preferably, the maintenance period is 25-30 days.
[0025] The beneficial effects achieved by one or more embodiments of the present invention described above are as follows:
[0026] By combining bamboo waste with modified magnesium oxysulfate inorganic adhesive, modified magnesium oxysulfate inorganic adhesive bamboo chip boards are prepared. These boards are free of harmful substances, have excellent mechanical properties, are fire-resistant, moisture-proof, and durable. They can be applied to fields such as construction, furniture, and decorative materials. They can reduce energy consumption in the production of building materials and also fix carbon, reducing carbon dioxide emissions. They have both green and economic significance.
[0027] The modified magnesium oxysulfate inorganic adhesive prepared by this invention has a 28-day compressive strength of 63–95 MPa and a flexural strength of 7.5–15 MPa. The prepared modified magnesium oxysulfate inorganic adhesive bamboo chipboard has a 28-day compressive strength of 34–55 MPa and a flexural strength of 12–18 MPa. Attached Figure Description
[0028] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.
[0029] Figure 1 shows the flexural strength test apparatus (A) and specimen failure diagram (B) of the modified magnesium oxysulfate inorganic adhesive in Example 1;
[0030] Figure 2 shows the compressive strength test apparatus (A) and specimen failure diagram (B) of the modified magnesium oxysulfate inorganic adhesive in Example 1;
[0031] Figure 3 is a diagram of the compressive strength test apparatus in Example 2;
[0032] Figure 4 shows the compressive strength test apparatus in Comparative Example 1;
[0033] Figure 5 shows the flexural strength test apparatus (A) and specimen failure diagram (B) in Example 2;
[0034] Figure 6 shows the flexural strength test setup (A) and specimen failure diagram (B) in Comparative Example 1. Detailed Implementation
[0035] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.
[0036] The present invention will be further described below with reference to the embodiments.
[0037] In the following examples, the bamboo shavings were sieved through a 10-mesh sieve and purchased from Ya'ao (Shandong) Technology Co., Ltd.
[0038] The MgO content in the lightly calcined magnesium oxide is 98%–99%, and it passes through a 400-mesh sieve. It was purchased from Wuxi Zemei New Material Technology Co., Ltd.
[0039] Magnesium sulfate heptahydrate, purity ≥95%, industrial grade, passed through a 40-mesh sieve, purchased from Shandong Yongrui Salt Chemical Co., Ltd.
[0040] Silica fume, powder, passed through a 325-mesh sieve, purchased from Shijiazhuang Longcai Mineral Products Co., Ltd.
[0041] Silica sol, liquid, 30% content, purchased from Jinan Hongxinda Biotechnology Co., Ltd.
[0042] Lithium silicate, liquid, 25% content, purchased from Henan Youyang Chemical Products Co., Ltd.
[0043] Sodium silicate, powder, passed through a 325-mesh sieve, dissolved in water beforehand, purchased from Luoyang Tongrun Information Technology Co., Ltd.
[0044] Citric acid, powder, dissolved in water beforehand, purchased from Sinopharm Chemical Reagent Co., Ltd.
[0045] Sodium tripolyphosphate, powder, dissolved in water beforehand, purchased from Sinopharm Chemical Reagent Co., Ltd.
[0046] Nano-silicon, powder, dissolved in water beforehand, Hubei Huifu Nanomaterials Co., Ltd.
[0047] Amphibole powder, powder, passed through a 300-mesh sieve, dissolved in water beforehand, purchased from Lingshou County Fengfeng Mineral Products Processing Plant;
[0048] Multi-walled carbon nanotubes, purity above 85.5%, powder, passed through a 20,000-mesh sieve, dissolved in water beforehand, purchased from Jiaxing Bona New Materials Co., Ltd.
[0049] Example 1
[0050] A modified magnesium sulfate inorganic adhesive, by weight, is composed of the following components: 100 parts of lightly calcined magnesium oxide, 30 parts of magnesium sulfate heptahydrate, 80 parts of water, 0.8 parts of silica fume, 0.5 parts of silica sol, 1.0 part of lithium silicate, 1.5 parts of sodium silicate, 1.5 parts of citric acid, 0.5 parts of sodium tripolyphosphate, 1.0 part of nano-silicon, 2.0 parts of amphibole powder, and 0.3 parts of multi-walled carbon nanotubes.
[0051] Preparation method:
[0052] Weigh each component according to the above material ratio, dissolve magnesium sulfate heptahydrate in water and stir, keeping the water temperature at 20℃, to obtain magnesium sulfate aqueous solution.
[0053] Subsequently, silica sol, lithium silicate, sodium silicate, citric acid, sodium tripolyphosphate, 1.0 part of nano-silicon, amphibole powder and multi-walled carbon nanotubes were added sequentially to the magnesium sulfate aqueous solution, and stirring was continued to ensure that all components were stirred evenly.
[0054] Finally, add lightly calcined magnesium oxide and silica fume and mix and stir until all components have fully reacted and are homogeneous to obtain modified magnesium oxysulfate inorganic adhesive.
[0055] Product performance: Testing the compressive strength and flexural strength of the inorganic adhesive.
[0056] The mixed modified magnesium oxysulfate inorganic adhesive was poured into a 40mm x 40mm x 160mm mold to make 6 specimens. The specimens were compacted by vibration and placed in a constant temperature (20±3℃) and constant humidity (60% RH) environment for 28 days. The compressive strength and flexural strength of the modified magnesium oxysulfate inorganic adhesive were tested respectively.
[0057] Figure 1 shows the comparison of the flexural strength of the modified magnesium oxysulfate inorganic adhesive in Example 1 before and after failure, as shown in Figure 1A and Figure 1B. After testing, the flexural strength of the six specimens after 28 days varied from 7.5 to 15 MPa, specifically 7.53 MPa, 11.29 MPa, 13.84 MPa, 14.32 MPa, 14.73 MPa, and 15.28 MPa, with an average of 13.0 MPa.
[0058] Figure 2 shows a comparison of the modified magnesium oxysulfate inorganic adhesive in Example 1 before and after failure in the compressive strength test, as shown in Figure 2A and Figure 2B. The compressive strength test used 12 specimens that had failed the flexural strength test. The 28-day compressive strength of the 12 specimens ranged from 63 to 95 MPa, specifically 63.42 MPa, 66.44 MPa, 69.32 MPa, 73.46 MPa, 78.67 MPa, 80.97 MPa, 82.93 MPa, 85.36 MPa, 86.43 MPa, 87.95 MPa, 90.89 MPa, and 95.06 MPa, with a mean of 79.24 MPa.
[0059] Example 2
[0060] A modified magnesium sulfate inorganic adhesive bamboo chip board, by weight, is composed of the following components: 30 parts bamboo chips, 100 parts lightly calcined magnesium oxide, 30 parts magnesium sulfate heptahydrate, 80 parts water, 0.8 parts silica fume, 0.5 parts silica sol, 1.0 part lithium silicate, 1.0 part nano-silicon, 1.5 parts sodium silicate, 1.5 parts citric acid, 0.5 parts sodium tripolyphosphate, 2.0 parts amphibole powder, and 0.3 parts multi-walled carbon nanotubes.
[0061] Preparation method:
[0062] Weigh each component according to the above material ratio, dissolve magnesium sulfate heptahydrate in water and stir, keeping the water temperature at 20℃, to obtain magnesium sulfate aqueous solution.
[0063] Subsequently, silica sol, lithium silicate, sodium silicate, citric acid, nano-silicon, amphibole powder, and multi-walled carbon nanotubes were added sequentially to the magnesium sulfate aqueous solution, and stirring was continued to ensure that all components were mixed evenly.
[0064] Finally, add lightly calcined magnesium oxide and silica fume and mix and stir until all components have fully reacted and are homogeneous to obtain modified magnesium oxysulfate inorganic adhesive.
[0065] The treated waste bamboo shavings were added to modified magnesium oxysulfate inorganic adhesive, stirred evenly, and then poured into a 40mm x 40mm x 160mm mold for pressing. The molded bamboo shaving boards were cured for 28 days in a constant temperature (20±3℃) and constant humidity (60% RH) environment. The resulting modified magnesium oxysulfate inorganic adhesive bamboo shaving board has a non-combustible rating of A1 and a formaldehyde emission of 0.
[0066] Comparative Example 1
[0067] Magnesium sulfide inorganic adhesive (authorization number CN 111423820B) bamboo chip board, by weight, is composed of the following components: 30 parts bamboo chips, 100 parts lightly calcined magnesium oxide, 30 parts magnesium sulfate heptahydrate, 60 parts water, 0.8 parts silica fume, 0.5 parts silica sol, 1.0 part lithium silicate, 1.5 parts sodium silicate, and 1.5 parts citric acid.
[0068] The preparation method is the same as in Example 2, except that the composition of the magnesium oxysulfate inorganic adhesive in Example 2 has been changed.
[0069] Comparative Example 2
[0070] The difference from Example 2 is that nano-silicon is replaced with silica ash, while everything else is the same as in Example 2.
[0071] Comparative Example 3
[0072] The difference from Example 2 is that nano-silicon is replaced with silica sol, while everything else is the same as in Example 2.
[0073] Comparative Example 4
[0074] The difference from Example 2 is that sodium tripolyphosphate is replaced with nano-silicon, while everything else is the same as in Example 2.
[0075] Comparative Example 5
[0076] The difference from Example 2 is that sodium tripolyphosphate is replaced with citric acid, while everything else is the same as in Example 2.
[0077] Comparative Example 6
[0078] The difference from Example 2 is that amphibole powder is replaced with multi-walled carbon nanotubes, while everything else is the same as in Example 2.
[0079] Comparative Example 7
[0080] The difference from Example 2 is that the multi-walled carbon nanotubes are replaced with sodium silicate, while everything else is the same as in Example 2.
[0081] The compressive and flexural strength of eight groups of inorganic adhesive bamboo chipboard specimens from Example 2 and the comparative example were tested in accordance with GB / T 17671-2021 "Test Method for Strength of Cement Mortar" (ISO method).
[0082] Figure 3 shows the compressive strength test apparatus in Example 2, and Figure 5 shows the flexural strength test apparatus (A) and specimen failure diagram (B) in Example 2. The compressive strength of the bamboo chipboard in Example 2 ranges from 34 to 55 MPa, specifically 34.32 MPa, 35.0 MPa, 35.53 MPa, 37.27 MPa, 38.10 MPa, 40.64 MPa, 42.76 MPa, 45.92 MPa, 48.81 MPa, 50.61 MPa, 52.38 MPa, and 54.97 MPa, with an average of 43.03 MPa.
[0083] The flexural strength ranges from 12 to 18 MPa, specifically 12.24 MPa, 12.76 MPa, 16.0 MPa, 16.53 MPa, 17.95 MPa, and 18.32 MPa, with an average of 15.64 MPa.
[0084] Figure 4 shows the compressive strength test apparatus in Comparative Example 1, and Figure 6 shows the flexural strength test apparatus (A) and specimen failure diagram (B) in Comparative Example 1. The compressive strength of Comparative Example 1 ranges from 12 to 30 MPa, specifically 12.43 MPa, 12.52 MPa, 13.96 MPa, 15.82 MPa, 17.71 MPa, 18.76 MPa, 20.45 MPa, 22.77 MPa, 24.51 MPa, 27.45 MPa, 28.82 MPa, and 30.42 MPa, with an average of 20.47 MPa.
[0085] The flexural strength ranges from 4 to 10 MPa, specifically 4.21 MPa, 6.75 MPa, 7.82 MPa, 8.56 MPa, 9.98 MPa, and 10.34 MPa, with an average of 7.94 MPa.
[0086] The compressive strength of Comparative Example 2 ranged from 38 to 60 MPa, specifically 38.25 MPa, 39.39 MPa, 39.62 MPa, 40.05 MPa, 43.72 MPa, 45.21 MPa, 46.06 MPa, 48.51 MPa, 50.81 MPa, 55.44 MPa, 58.76 MPa, and 60.16 MPa, with an average of 47.17 MPa.
[0087] The flexural strength ranges from 7 to 13 MPa, specifically 7.12 MPa, 7.35 MPa, 8.97 MPa, 10.24 MPa, 12.75 MPa, and 13.38 MPa, with an average of 9.97 MPa.
[0088] The compressive strength of Comparative Example 3 ranged from 21 to 45 MPa, specifically 21.44 MPa, 23.17 MPa, 26.58 MPa, 28.95 MPa, 33.62 MPa, 37.11 MPa, 39.52 MPa, 40.61 MPa, 42.88 MPa, 44.21 MPa, 44.74 MPa, and 45.39 MPa, with an average of 35.69 MPa.
[0089] The flexural strength ranges from 7.8 to 15 MPa, specifically 7.88 MPa, 8.96 MPa, 10.54 MPa, 11.02 MPa, 13.43 MPa, and 15.72 MPa, with an average of 11.26 MPa.
[0090] Comparative Example 4 has compressive strengths ranging from 20 to 50 MPa, specifically 20.52 MPa, 22.14 MPa, 26.96 MPa, 29.27 MPa, 35.94 MPa, 39.93 MPa, 41.81 MPa, 43.85 MPa, 44.01 MPa, 46.96 MPa, 48.75 MPa, and 50.17 MPa, with an average of 37.53 MPa.
[0091] The flexural strength ranges from 7 to 16 MPa, specifically 7.20 MPa, 9.87 MPa, 11.06 MPa, 13.35 MPa, 14.98 MPa, and 16.56 MPa, with an average of 12.17 MPa.
[0092] The compressive strength of Comparative Example 5 ranged from 37 to 56 MPa, specifically 37.58 MPa, 39.18 MPa, 40.99 MPa, 41.23 MPa, 42.08 MPa, 43.65 MPa, 45.3 MPa, 48.72 MPa, 52.06 MPa, 53.39 MPa, 55.47 MPa, and 56.26 MPa, with an average of 46.33 MPa.
[0093] The flexural strength ranges from 7 to 15 MPa, specifically 7.53 MPa, 8.45 MPa, 11.76 MPa, 13.26 MPa, 14.94 MPa, and 15.22 MPa, with an average of 11.86 MPa.
[0094] The compressive strength of Comparative Example 6 ranged from 24 to 43 MPa, specifically 24.23 MPa, 26.64 MPa, 28.98 MPa, 29.74 MPa, 32.62 MPa, 36.86 MPa, 38.05 MPa, 39.73 MPa, 41.21 MPa, 41.97 MPa, 42.31 MPa, and 43.08 MPa, with an average of 35.45 MPa.
[0095] The flexural strength ranges from 7 to 16 MPa, specifically 7.26 MPa, 8.55 MPa, 10.94 MPa, 13.68 MPa, 15.13 MPa, and 16.07 MPa, with an average of 11.94 MPa.
[0096] The compressive strength of Comparative Example 7 ranged from 26 to 56 MPa, specifically 26.46 MPa, 28.62 MPa, 29.31 MPa, 32.44 MPa, 35.73 MPa, 40.25 MPa, 41.25 MPa, 43.89 MPa, 46.93 MPa, 49.04 MPa, 51.22 MPa, and 52.67 MPa, with an average of 39.82 MPa.
[0097] The flexural strength ranges from 6 to 17 MPa, specifically 6.13 MPa, 8.34 MPa, 10.69 MPa, 12.75 MPa, 15.42 MPa, and 17.05 MPa, with an average of 11.73 MPa.
[0098] Table 1 Comparison of compressive strength and flexural strength between Example 2 and the comparative example.
[0099] Experiments revealed that the addition of bamboo shavings altered the material's density and pore structure, resulting in a significantly lower compressive strength for the bamboo shaving board compared to the adhesive block. However, bamboo shavings, as a natural fiber, significantly improved the material's toughness and flexural strength. Comparative results from Example 2 and Comparative Example 1 showed that the modified magnesium oxysulfate inorganic adhesive bamboo shaving board exhibited significantly improved compressive and flexural strength.
[0100] If the components of the modified magnesium oxysulfate inorganic adhesive are replaced, such as in Comparative Examples 2 and 3, by replacing it with nano-silicon, the experimental results of Comparative Examples 2, 3, and Example 2 show that the addition of nano-silicon plays an important role in the modified magnesium oxysulfate inorganic adhesive bamboo chip board. It not only enhances the strength of the inorganic adhesive but also improves the bonding performance between the adhesive and bamboo chips, significantly increasing the compressive and flexural strength of the bamboo chip board. This indicates that nano-silicon, as an effective modifier, has advantages that are difficult to replace with other components (such as silica fume and silica sol) in enhancing the adhesion between the adhesive and bamboo chips.
[0101] Similarly, sodium tripolyphosphate, amphibole powder, and multi-walled carbon nanotubes were substituted in Comparative Examples 4 to 7, respectively. Comparison with the experimental results of the Examples revealed that sodium tripolyphosphate, amphibole powder, and multi-walled carbon nanotubes play an important role in improving the strength of the colloid and the bonding performance between the colloid and the bamboo chips in the modified magnesium oxysulfate inorganic adhesive bamboo chip board.
[0102] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A modified magnesium oxysulfate inorganic adhesive, characterized in that: By weight, it consists of the following components: 100 parts of lightly calcined magnesium oxide, 20-60 parts of magnesium sulfate heptahydrate, 50-85 parts of water, 1.1-17 parts of modifier, and 1.8-5.3 parts of stabilizer; The modifier comprises: 0.2-3 parts citric acid, 0.5-8 parts silica fume, 0.1-3 parts silica sol, 0.2-2 parts lithium silicate, 0.1-1 parts sodium tripolyphosphate, and 0.5-5 parts nano-silicon; The stabilizer comprises: 1-3.5 parts of amphibole powder, 0.5-3 parts of sodium silicate, and 0.3-0.8 parts of multi-walled carbon nanotubes.
2. The modified magnesium oxysulfate inorganic adhesive according to claim 1, characterized in that: By weight, it consists of the following components: 100 parts of lightly calcined magnesium oxide, 20-40 parts of magnesium sulfate heptahydrate, 60-85 parts of water, 4-15 parts of modifier, and 3-5 parts of stabilizer.
3. The modified magnesium oxysulfate inorganic adhesive according to claim 2, characterized in that: The modifier comprises: 1-3 parts citric acid, 0.5-5 parts silica fume, 0.3-2 parts silica sol, 0.2-1 parts lithium silicate, 0.3-1 parts sodium tripolyphosphate, and 0.5-3 parts nano-silicon.
4. The modified magnesium oxysulfate inorganic adhesive according to claim 2, characterized in that: The stabilizer comprises: 1.5 to 3 parts of amphibole powder, 1 to 2 parts of sodium silicate, and 0.3 to 0.5 parts of multi-walled carbon nanotubes.
5. The method for preparing the modified magnesium oxysulfate inorganic adhesive according to any one of claims 1-4, characterized in that: The steps include: dissolving magnesium sulfate heptahydrate in water to obtain a magnesium sulfate solution; Then, silica sol, lithium silicate, sodium silicate, citric acid, sodium tripolyphosphate, nano-silicon, amphibole powder and multi-walled carbon nanotubes were added to magnesium sulfate aqueous solution in proportion. After stirring and mixing, lightly calcined magnesium oxide and silica fume were added and mixed. After the reaction was completed, modified magnesium sulfate inorganic adhesive was obtained.
6. A bamboo shaving board, characterized in that: It is prepared by mixing the modified magnesium oxysulfate inorganic adhesive as described in claims 1-4 with bamboo chips in a mass ratio of 6-8:2-4.
7. The bamboo shavings board according to claim 6, characterized in that: The method for preparing the bamboo chip board is as follows: bamboo chips produced during bamboo processing, and dead or soon-to-be-dead bamboo are chipped into bamboo chips. After drying the bamboo shavings, they are mixed with the modified magnesium oxysulfate inorganic adhesive at a mass ratio of 2-4:6-8. The mixture is poured into a mold, pressed into shape, and cured to obtain a bamboo shaving board.
8. The bamboo shavings board according to claim 7, characterized in that: The bamboo shavings are sieved, and the diameter of the sieved bamboo shavings does not exceed 2mm and the length does not exceed 10mm.
9. The bamboo shavings board according to claim 7, characterized in that: The dried bamboo shavings have a moisture content of less than 10%.
10. The bamboo shavings board according to claim 7, characterized in that: The curing conditions are 20±3℃; relative humidity 60%RH; and the curing time is 25-30 days.