A bio-based lightweight gypsum board and preparation method thereof

Abstract

The invention relates to the technical field of gypsum boards, and in particular to a bio-based lightweight gypsum board and a preparation method thereof. According to the invention, surface sulfonated modified bamboo fiber, alkalized abaca fiber and modified straw ash are mixed and then sprayed with a silane coupling agent solution on the surface, so that the silane coupling agent can form a layer of chemical bonds on the surface of the fiber and gypsum particles, thereby enhancing the bonding ability of the gypsum with other substances. Meanwhile, the silane coupling agent can also ensure that the moisture on the surface of the gypsum is not easy to volatilize, thereby preventing premature dehydration and the generation of cracks. Secondly, the addition of an organic waterproofing agent can improve the waterproof performance of the gypsum board, prevent the intrusion of moisture, and enhance the water resistance of the gypsum. The organic waterproofing agent can change the structure of holes, pores and capillaries on the inner surface of a gypsum product, thereby changing the hydrophilic surface into a hydrophobic surface, thereby preventing the intrusion of moisture, forming more and more water-blocking films on the surface of the gypsum voids, and significantly reducing the water absorption of the gypsum product.

Description

Technical Field

[0001] This invention relates to the field of gypsum board technology, specifically to a bio-based lightweight gypsum board and its preparation method. Background Art

[0002] With the continuous development of the construction industry, the requirements for building materials are also increasing. Although traditional gypsum board has excellent fire resistance and processing performance, its heavy weight and susceptibility to moisture and cracking limit its application in certain fields. Therefore, developing a new type of gypsum board with lightweight and excellent waterproof performance has become a current research hotspot.

[0003] Traditional gypsum board mainly consists of gypsum, fiber reinforcement materials, and additives. The fiber reinforcement materials typically use inorganic or synthetic fibers such as glass fiber and paper fiber to improve the strength and toughness of the board. However, while these fiber materials improve the board's performance, they also increase its weight and offer limited improvement in waterproofing. Furthermore, to improve the waterproofing of gypsum board, some researchers have attempted to add waterproofing agents. However, commonly used waterproofing agents, such as silicone waterproofing agents, while having good waterproofing effects, have poor compatibility with the gypsum matrix, easily leading to cracking and peeling during use. Therefore, designing a new method for preparing gypsum board that improves both its performance and waterproofing has become a pressing technical problem for those skilled in the art. Summary of the Invention

[0004] Technical problems to be solved

[0005] In view of the above-mentioned shortcomings of the existing technology, the present invention provides a bio-based lightweight gypsum board and its preparation method, which can effectively solve the problems of heavy weight and poor performance of existing gypsum boards.

[0006] Technical solution

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A bio-based lightweight gypsum board, the composition of which includes: surface sulfonated modified bamboo fiber, alkalized abaca fiber, modified straw ash, silane coupling agent solution, organic waterproofing agent, sodium dodecylbenzene sulfonate, distilled water and desulfurized gypsum powder.

[0009] The surface sulfonated modified bamboo fiber is obtained by sulfonating bamboo fiber;

[0010] The alkalized abaca fiber is obtained by alkalizing abaca fiber with sodium hydroxide.

[0011] The modified straw ash is made from corn straw and wheat straw;

[0012] The organic waterproofing agent is prepared by introducing amino, vinyl, and epoxy groups into the organosilicon chain segment.

[0013] Furthermore, the preparation method of the surface sulfonated modified bamboo fiber is as follows:

[0014] S1. Bamboo fiber was immersed in a 10% hydrogen peroxide solution at a material-to-liquid ratio of 1:20 g / mL, kept at 140℃ for 6 hours, cooled to room temperature, filtered, washed 3 times with distilled water, and dried in an oven at 45℃ for 2 hours. This was recorded as pretreated bamboo fiber.

[0015] S2. Weigh 10 parts by weight of pretreated bamboo fiber, 25 parts by weight of sodium sulfite, 2 parts by weight of sodium hydroxide, 0.5 parts by weight of anthraquinone and 450 parts by weight of deionized water and pour them into a reaction vessel. Heat to 170°C and keep the temperature for 4 hours. After the reaction is completed, cool to room temperature and wash with distilled water until neutral. Place in an oven at 50°C and dry for 1 hour to obtain surface sulfonated modified bamboo fiber.

[0016] Furthermore, the preparation method of the alkalized abaca fiber is as follows: the abaca fiber is immersed in a 30% sodium hydroxide solution at a material-to-liquid ratio of 1:20 g / mL, kept at 70°C for 6 hours, cooled to room temperature, rinsed with distilled water until neutral, and dried in an oven at 50°C for 12 hours. The result is the alkalized abaca fiber.

[0017] Furthermore, the method for preparing the modified straw ash is as follows:

[0018] 1) Mix corn stalks and wheat stalks in equal weight ratio and burn them at 600℃ for 30 minutes. Then, grind them in a ball mill at a material-to-ball ratio of 1:18 for 90 minutes. The result is recorded as the straw ash component.

[0019] 2) The straw ash component was immersed in a 3% citric acid solution at a material-to-liquid ratio of 1:15 g / mL. After soaking for 12 hours, it was rinsed with distilled water until neutral and then dried at 105℃ to constant weight. The result is the modified straw ash.

[0020] Furthermore, the silane coupling agent solution is prepared by mixing silane coupling agent KH-560 and anhydrous ethanol at a weight ratio of 1:10 and stirring at a stirring speed of 500-600 r / min for 10 min, which yields the silane coupling agent solution.

[0021] Furthermore, the preparation steps of the organic waterproofing agent are as follows:

[0022] Step 1: Weigh 25-30 parts by weight of octamethylcyclotetrasiloxane, 0.5-0.8 parts by weight of tetramethylammonium hydroxide, and 200 parts by weight of distilled water and add them to a flask. React at 90-100℃ for 1 hour, then cool to 60℃. Next, add 12-15 parts by weight of N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane coupling agent, 5-6 parts by weight of vinyltrimethoxysilane, and 0.3-0.5 parts by weight of tetramethylammonium hydroxide. Heat to 120℃ and react for 2 hours. The result is recorded as the reaction component.

[0023] Step 2: Cool the reaction components to 80℃ and evacuate for 30 minutes. Then add 200-300 parts by weight of isopropanol and stir at 200 r / min for 30 minutes. Add glacial acetic acid to adjust the pH to 6, then add 38-40 parts by weight of epichlorohydrin. Stir at 500 r / min for 5 minutes and then react at 70℃ for 2 hours. The result is the organic waterproofing agent.

[0024] A method for preparing a bio-based lightweight gypsum board, the method comprising the following steps:

[0025] Step 1: Mix surface sulfonated modified bamboo fiber, alkalized abaca fiber and modified straw ash in equal weight ratio, stir at 200-300 r / min for 10 min and record as bio-based component. Spray 20% by weight of silane coupling agent solution evenly on the surface of bio-based component and record as modified bio-based component.

[0026] Step 2: Weigh 3-5 parts by weight of organic waterproofing agent, 2-3 parts by weight of sodium dodecylbenzenesulfonate and 100 parts by weight of distilled water, mix them and stir at 300 r / min for 5 min. The result is recorded as the dispersion component.

[0027] Step 3: Mix 50 parts by weight of modified bio-based component, 80 parts by weight of dispersion component and 150 parts by weight of desulfurized gypsum powder, stir at 200 r / min for 30 min, pour into mold and harden for 2 h. The result after demolding is bio-based lightweight gypsum board.

[0028] Beneficial effects

[0029] This invention provides a bio-based lightweight gypsum board and its preparation method. Compared with existing technologies, this invention has the following advantages:

[0030] 1. This invention modifies the surface of bamboo fiber by sulfonation, introducing sulfonic acid groups onto the surface of the bamboo fiber. These sulfonic acid groups are hydrophilic, enhancing the dispersibility and wettability of bamboo fiber in water-based systems, thereby strengthening the interaction between the bamboo fiber and the gypsum matrix, making them easier to bond, and thus improving the uniform distribution and stability of the bamboo fiber in the gypsum board. Secondly, after alkalization treatment, some non-cellulose components on the surface of abaca fiber, such as lignin, hemicellulose, and pectin, are removed, making the fiber surface rougher and increasing the contact area with the gypsum matrix, thereby improving… Improving the interfacial bonding between the two, the addition of alkalized abaca fiber to gypsum board enhances its resistance to deformation under external impact, improving its toughness and durability. Finally, this invention prepares straw ash components from burning corn stalks and wheat stalks. After citric acid treatment, these ash components are added to gypsum board, improving its compressive and bending mechanical properties. Furthermore, the citric acid-treated straw ash may exhibit better dispersibility and compatibility with the gypsum matrix, addressing the issue of reduced porosity in the internal structure of the gypsum board and thus increasing its density.

[0031] 2. This invention involves mixing surface-sulfonated modified bamboo fiber, alkalized abaca fiber, and modified straw ash, then spraying the mixture with a silane coupling agent solution. This allows the silane coupling agent to form a chemical bond on the surface of the fibers and gypsum particles, enhancing the adhesion of gypsum to other substances. Simultaneously, the silane coupling agent ensures that moisture on the gypsum surface does not easily evaporate, preventing premature dehydration and cracking. Furthermore, the addition of an organic waterproofing agent improves the waterproof performance of the gypsum board, preventing water intrusion and enhancing the water resistance of the gypsum. The organic waterproofing agent can alter the structure of pores, voids, and capillaries on the internal surface of gypsum products, making them more... The surface is transformed from hydrophilic to hydrophobic, preventing water intrusion and forming an increasing number of water-resistant films on the gypsum pore surface, significantly reducing the water absorption of gypsum products. Finally, through the synergistic effect between fiber materials, the durability of gypsum board is significantly improved, enabling it to better resist environmental factors such as wind, rain, and temperature changes, thereby extending the service life of gypsum board. Moreover, most of the fiber materials and additives are derived from natural renewable resources such as bamboo, abaca, and straw, which meet the requirements of environmental protection and sustainability, while also reducing the production cost of gypsum board and improving its cost-effectiveness. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0033] The present invention will be further described below with reference to embodiments.

[0034] Example 1

[0035] This embodiment describes a bio-based lightweight gypsum board. The bio-based lightweight gypsum board comprises: surface sulfonated modified bamboo fiber, alkalized abaca fiber, modified straw ash, silane coupling agent solution, organic waterproofing agent, sodium dodecylbenzene sulfonate, distilled water, and desulfurized gypsum powder.

[0036] Surface-sulfonated modified bamboo fiber is obtained by sulfonating bamboo fiber. The preparation method of surface-sulfonated modified bamboo fiber is as follows:

[0037] S1. Bamboo fiber was immersed in a 10% hydrogen peroxide solution at a material-to-liquid ratio of 1:20 g / mL, kept at 140℃ for 6 hours, cooled to room temperature, filtered, washed 3 times with distilled water, and dried in an oven at 45℃ for 2 hours. This was recorded as pretreated bamboo fiber.

[0038] S2. Weigh 10 parts by weight of pretreated bamboo fiber, 25 parts by weight of sodium sulfite, 2 parts by weight of sodium hydroxide, 0.5 parts by weight of anthraquinone and 450 parts by weight of deionized water and pour them into a reaction vessel. Heat to 170°C and keep the temperature for 4 hours. After the reaction is completed, cool to room temperature and wash with distilled water until neutral. Place in an oven at 50°C and dry for 1 hour to obtain surface sulfonated modified bamboo fiber.

[0039] Alkali-treated abaca fiber is obtained by alkalizing abaca fiber with sodium hydroxide. The preparation method of alkalizing abaca fiber is as follows: the abaca fiber is immersed in a 30% sodium hydroxide solution at a material-to-liquid ratio of 1:20 g / mL, kept at 70°C for 6 hours, cooled to room temperature, rinsed with distilled water until neutral, and dried in an oven at 50°C for 12 hours. The result is alkalized abaca fiber.

[0040] Modified straw ash is produced from corn straw and wheat straw as raw materials. The preparation method of modified straw ash is as follows:

[0041] 1) Mix corn stalks and wheat stalks in equal weight ratio and burn them at 600℃ for 30 minutes. Then, grind them in a ball mill at a material-to-ball ratio of 1:18 for 90 minutes. The result is recorded as the straw ash component.

[0042] 2) The straw ash component was immersed in a 3% citric acid solution at a material-to-liquid ratio of 1:15 g / mL. After soaking for 12 hours, it was rinsed with distilled water until neutral and then dried at 105℃ to constant weight. The result is the modified straw ash.

[0043] The preparation method of silane coupling agent solution is as follows: silane coupling agent KH-560 and anhydrous ethanol are mixed at a weight ratio of 1:10 and stirred at a stirring speed of 500r / min for 10min to obtain silane coupling agent solution.

[0044] Organic waterproofing agents are prepared by introducing amino, vinyl, and epoxy groups into organosilicon segments. The preparation steps of the organic waterproofing agent are as follows:

[0045] Step 1: Weigh 25 parts by weight of octamethylcyclotetrasiloxane, 0.5 parts by weight of tetramethylammonium hydroxide and 200 parts by weight of distilled water and add them to a flask. React at 90°C for 1 hour, then cool down to 60°C. Next, add 12 parts by weight of N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane coupling agent, 5 parts by weight of vinyltrimethoxysilane and 0.3 parts by weight of tetramethylammonium hydroxide. Heat to 120°C and react for 2 hours. The result is recorded as the reaction component.

[0046] Step 2: Cool the reaction components to 80℃ and evacuate for 30 minutes. Then add 200 parts by weight of isopropanol and stir at 200 r / min for 30 minutes. Add glacial acetic acid to adjust the pH to 6, then add 38 parts by weight of epichlorohydrin. Stir at 500 r / min for 5 minutes and then react at 70℃ for 2 hours. The result is the organic waterproofing agent.

[0047] A method for preparing bio-based lightweight gypsum board, the method comprising the following steps:

[0048] Step 1: Mix surface sulfonated modified bamboo fiber, alkalized abaca fiber and modified straw ash in equal weight ratio, stir at 200 r / min for 10 min and record as bio-based component. Spray 20% by weight of silane coupling agent solution evenly on the surface of bio-based component and record as modified bio-based component.

[0049] Step 2: Weigh 3 parts by weight of organic waterproofing agent, 2 parts by weight of sodium dodecylbenzenesulfonate and 100 parts by weight of distilled water, mix them and stir at 300 r / min for 5 min. The result is recorded as the dispersion component.

[0050] Step 3: Mix 50 parts by weight of modified bio-based component, 80 parts by weight of dispersion component and 150 parts by weight of desulfurized gypsum powder, stir at 200 r / min for 30 min, pour into mold and harden for 2 h. The result after demolding is bio-based lightweight gypsum board.

[0051] Example 2

[0052] This embodiment describes a bio-based lightweight gypsum board. The bio-based lightweight gypsum board comprises: surface sulfonated modified bamboo fiber, alkalized abaca fiber, modified straw ash, silane coupling agent solution, organic waterproofing agent, sodium dodecylbenzene sulfonate, distilled water, and desulfurized gypsum powder.

[0053] Surface-sulfonated modified bamboo fiber is obtained by sulfonating bamboo fiber. The preparation method of surface-sulfonated modified bamboo fiber is as follows:

[0054] S1. Bamboo fiber was immersed in a 10% hydrogen peroxide solution at a material-to-liquid ratio of 1:20 g / mL, kept at 140℃ for 6 hours, cooled to room temperature, filtered, washed 3 times with distilled water, and dried in an oven at 45℃ for 2 hours. This was recorded as pretreated bamboo fiber.

[0055] S2. Weigh 10 parts by weight of pretreated bamboo fiber, 25 parts by weight of sodium sulfite, 2 parts by weight of sodium hydroxide, 0.5 parts by weight of anthraquinone and 450 parts by weight of deionized water and pour them into a reaction vessel. Heat to 170°C and keep the temperature for 4 hours. After the reaction is completed, cool to room temperature and wash with distilled water until neutral. Place in an oven at 50°C and dry for 1 hour to obtain surface sulfonated modified bamboo fiber.

[0056] Alkali-treated abaca fiber is obtained by alkalizing abaca fiber with sodium hydroxide. The preparation method of alkalizing abaca fiber is as follows: the abaca fiber is immersed in a 30% sodium hydroxide solution at a material-to-liquid ratio of 1:20 g / mL, kept at 70°C for 6 hours, cooled to room temperature, rinsed with distilled water until neutral, and dried in an oven at 50°C for 12 hours. The result is alkalized abaca fiber.

[0057] Modified straw ash is produced from corn straw and wheat straw as raw materials. The preparation method of modified straw ash is as follows:

[0058] 1) Mix corn stalks and wheat stalks in equal weight ratio and burn them at 600℃ for 30 minutes. Then, grind them in a ball mill at a material-to-ball ratio of 1:18 for 90 minutes. The result is recorded as the straw ash component.

[0059] 2) The straw ash component was immersed in a 3% citric acid solution at a material-to-liquid ratio of 1:15 g / mL. After soaking for 12 hours, it was rinsed with distilled water until neutral and then dried at 105℃ to constant weight. The result is the modified straw ash.

[0060] The preparation method of silane coupling agent solution is as follows: silane coupling agent KH-560 and anhydrous ethanol are mixed at a weight ratio of 1:10 and stirred at a stirring speed of 600r / min for 10min to obtain silane coupling agent solution.

[0061] Organic waterproofing agents are prepared by introducing amino, vinyl, and epoxy groups into organosilicon segments. The preparation steps of the organic waterproofing agent are as follows:

[0062] Step 1: Weigh 30 parts by weight of octamethylcyclotetrasiloxane, 0.8 parts by weight of tetramethylammonium hydroxide and 200 parts by weight of distilled water and add them to a flask. React at 100°C for 1 hour, then cool down to 60°C. Next, add 15 parts by weight of N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane coupling agent, 6 parts by weight of vinyltrimethoxysilane and 0.5 parts by weight of tetramethylammonium hydroxide. Heat to 120°C and react for 2 hours. The result is recorded as the reaction component.

[0063] Step 2: Cool the reaction components to 80℃ and evacuate for 30 minutes. Then add 300 parts by weight of isopropanol and stir at 200 r / min for 30 minutes. Add glacial acetic acid to adjust the pH to 6, then add 40 parts by weight of epichlorohydrin and stir at 500 r / min for 5 minutes. Then place the mixture at 70℃ for 2 hours to react. The result is the organic waterproofing agent.

[0064] A method for preparing bio-based lightweight gypsum board, the method comprising the following steps:

[0065] Step 1: Mix surface sulfonated modified bamboo fiber, alkalized abaca fiber and modified straw ash in equal weight ratio, stir at 300 r / min for 10 min and record as bio-based component. Spray 20% by weight of silane coupling agent solution evenly on the surface of bio-based component and record as modified bio-based component.

[0066] Step 2: Weigh 5 parts by weight of organic waterproofing agent, 3 parts by weight of sodium dodecylbenzenesulfonate and 100 parts by weight of distilled water, mix them and stir at a stirring speed of 300 r / min for 5 min. The result is recorded as the dispersion component.

[0067] Step 3: Mix 50 parts by weight of modified bio-based component, 80 parts by weight of dispersion component and 150 parts by weight of desulfurized gypsum powder, stir at 200 r / min for 30 min, pour into mold and harden for 2 h. The result after demolding is bio-based lightweight gypsum board.

[0068] Example 3

[0069] This embodiment describes a bio-based lightweight gypsum board. The bio-based lightweight gypsum board comprises: surface sulfonated modified bamboo fiber, alkalized abaca fiber, modified straw ash, silane coupling agent solution, organic waterproofing agent, sodium dodecylbenzene sulfonate, distilled water, and desulfurized gypsum powder.

[0070] Surface-sulfonated modified bamboo fiber is obtained by sulfonating bamboo fiber. The preparation method of surface-sulfonated modified bamboo fiber is as follows:

[0071] S1. Bamboo fiber was immersed in a 10% hydrogen peroxide solution at a material-to-liquid ratio of 1:20 g / mL, kept at 140℃ for 6 hours, cooled to room temperature, filtered, washed 3 times with distilled water, and dried in an oven at 45℃ for 2 hours. This was recorded as pretreated bamboo fiber.

[0072] S2. Weigh 10 parts by weight of pretreated bamboo fiber, 25 parts by weight of sodium sulfite, 2 parts by weight of sodium hydroxide, 0.5 parts by weight of anthraquinone and 450 parts by weight of deionized water and pour them into a reaction vessel. Heat to 170°C and keep the temperature for 4 hours. After the reaction is completed, cool to room temperature and wash with distilled water until neutral. Place in an oven at 50°C and dry for 1 hour to obtain surface sulfonated modified bamboo fiber.

[0073] Alkali-treated abaca fiber is obtained by alkalizing abaca fiber with sodium hydroxide. The preparation method of alkalizing abaca fiber is as follows: the abaca fiber is immersed in a 30% sodium hydroxide solution at a material-to-liquid ratio of 1:20 g / mL, kept at 70°C for 6 hours, cooled to room temperature, rinsed with distilled water until neutral, and dried in an oven at 50°C for 12 hours. The result is alkalized abaca fiber.

[0074] Modified straw ash is produced from corn straw and wheat straw as raw materials. The preparation method of modified straw ash is as follows:

[0075] 1) Mix corn stalks and wheat stalks in equal weight ratio and burn them at 600℃ for 30 minutes. Then, grind them in a ball mill at a material-to-ball ratio of 1:18 for 90 minutes. The result is recorded as the straw ash component.

[0076] 2) The straw ash component was immersed in a 3% citric acid solution at a material-to-liquid ratio of 1:15 g / mL. After soaking for 12 hours, it was rinsed with distilled water until neutral and then dried at 105℃ to constant weight. The result is the modified straw ash.

[0077] The preparation method of silane coupling agent solution is as follows: silane coupling agent KH-560 and anhydrous ethanol are mixed at a weight ratio of 1:10 and stirred at a stirring speed of 600r / min for 10min to obtain silane coupling agent solution.

[0078] Organic waterproofing agents are prepared by introducing amino, vinyl, and epoxy groups into organosilicon segments. The preparation steps of the organic waterproofing agent are as follows:

[0079] Step 1: Weigh 28 parts by weight of octamethylcyclotetrasiloxane, 0.7 parts by weight of tetramethylammonium hydroxide and 200 parts by weight of distilled water and add them to a flask. React at 95°C for 1 hour, then cool down to 60°C. Next, add 13 parts by weight of N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane coupling agent, 5 parts by weight of vinyltrimethoxysilane and 0.4 parts by weight of tetramethylammonium hydroxide. Heat to 120°C and react for 2 hours. The result is recorded as the reaction component.

[0080] Step 2: Cool the reaction components to 80℃ and evacuate for 30 minutes. Then add 300 parts by weight of isopropanol and stir at 200 r / min for 30 minutes. Add glacial acetic acid to adjust the pH to 6, then add 39 parts by weight of epichlorohydrin and stir at 500 r / min for 5 minutes. Then place the mixture at 70℃ for 2 hours to react. The result is the organic waterproofing agent.

[0081] A method for preparing bio-based lightweight gypsum board, the method comprising the following steps:

[0082] Step 1: Mix surface sulfonated modified bamboo fiber, alkalized abaca fiber and modified straw ash in equal weight ratio, stir at 300 r / min for 10 min and record as bio-based component. Spray 20% by weight of silane coupling agent solution evenly on the surface of bio-based component and record as modified bio-based component.

[0083] Step 2: Weigh 4 parts by weight of organic waterproofing agent, 3 parts by weight of sodium dodecylbenzenesulfonate and 100 parts by weight of distilled water, mix them and stir at a stirring speed of 300 r / min for 5 min. The result is recorded as the dispersion component.

[0084] Step 3: Mix 50 parts by weight of modified bio-based component, 80 parts by weight of dispersion component and 150 parts by weight of desulfurized gypsum powder, stir at 200 r / min for 30 min, pour into mold and harden for 2 h. The result after demolding is bio-based lightweight gypsum board.

[0085] Comparative Example 1

[0086] The bio-based lightweight gypsum board and its preparation method provided in this comparative example are largely the same as those in Example 1. The main difference is that the surface sulfonated modified bamboo fiber in Example 1 is replaced with alkalized abaca fiber in Example 1.

[0087] Comparative Example 2

[0088] The bio-based lightweight gypsum board and its preparation method provided in this comparative example are largely the same as those in Example 1. The main difference is that the alkalized abaca fiber in Example 1 is replaced with the modified straw ash in Example 1.

[0089] Comparative Example 3

[0090] The bio-based lightweight gypsum board and its preparation method provided in this comparative example are largely the same as those in Example 1. The main difference is that the modified straw ash in Example 1 is replaced with the surface sulfonated modified bamboo fiber in Example 1.

[0091] Comparative Example 4

[0092] The bio-based lightweight gypsum board and its preparation method provided in this comparative example are largely the same as those in Example 1, except that the silane coupling agent solution in Example 1 is replaced with distilled water in this comparative example 4.

[0093] Performance Testing

[0094] The bio-based lightweight gypsum boards from Examples 1-3 and Comparative Examples 1-3 were labeled as Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2, Comparative Example 3, and Comparative Example 4, respectively. The performance of Examples 1-3 and Comparative Examples 1-4 was then tested according to GB / T17669.3-1999, "Determination of Mechanical Properties of Building Gypsum." The obtained data are recorded in the table below:

[0095]

[0096]

[0097] The data in the table above shows that the mechanical properties and water resistance of the bio-based lightweight gypsum boards in Examples 1-3 are superior to those in Comparative Examples 1-4. This indicates that mixing surface-sulfonated modified bamboo fiber, alkalized abaca fiber, and modified straw ash, and then treating them with a silane coupling agent before adding them to the gypsum board can result in gypsum boards with superior performance. Therefore, the bio-based lightweight gypsum board and its preparation method in this invention have excellent market promotion value.

[0098] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0099] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A bio-based lightweight gypsum board, characterized in that: The composition of the bio-based lightweight gypsum board includes: surface sulfonated modified bamboo fiber, alkalized abaca fiber, modified straw ash, silane coupling agent solution, organic waterproofing agent, sodium dodecylbenzene sulfonate, distilled water and desulfurized gypsum powder; The surface sulfonated modified bamboo fiber is obtained by sulfonating and modifying the bamboo fiber; The alkalized abaca fiber is obtained by alkalizing the abaca fiber with sodium hydroxide; The modified straw ash is prepared using corn straw and wheat straw as raw materials; The organic waterproofing agent is prepared by introducing amino, vinyl and epoxy groups into the organosilicon chain segment; The preparation method of the surface sulfonated modified bamboo fiber is as follows: S1. Immerse the bamboo fiber in a 10% hydrogen peroxide solution at a solid-liquid ratio of 1:20 g / mL, keep it at 140°C for 6 hours, cool it to room temperature, filter it, wash it with distilled water for 3 times, and dry it to record it as pretreated bamboo fiber; S2, weighing 10 parts by weight of pretreated bamboo fiber, 25 parts by weight of sodium sulfite, 2 parts by weight of sodium hydroxide, 0.5 parts by weight of anthraquinone and 450 parts by weight of deionized water into a reactor, heating to 170° C. and then keeping the temperature for reaction for 4 hours, cooling to room temperature after the reaction, filtering and washing with distilled water until neutral, and drying to obtain the surface sulfonated modified bamboo fiber; The preparation method of the alkalized abaca fiber is as follows: immersing the abaca fiber in a sodium hydroxide solution with a mass fraction of 30% according to a material-liquid ratio of 1:20 g / mL, keeping the solution at 70°C for 6 hours, cooling the solution to room temperature, washing the solution with distilled water until the solution is neutral, and drying the solution in an oven at 50°C for 12 hours to obtain the alkalized abaca fiber; The preparation method of the modified straw ash is: 1) Corn straw and wheat straw were mixed in equal weight ratios and burned at 600°C for 30 min, and then ground in a ball mill for 90 min at a material-to-ball ratio of 1:

18. The result was recorded as the straw ash component; 2) The straw ash component was immersed in a 3% citric acid solution at a solid-liquid ratio of 1:15 g / mL, and then rinsed with distilled water until neutral, and then dried at 105°C to constant weight, and the resulting product was the modified straw ash; The preparation steps of the organic waterproofing agent are: Step 1, weigh 25-30 parts by weight of octamethylcyclotetrasiloxane, 0.5-0.8 parts by weight of tetramethylammonium hydroxide and 200 parts by weight of distilled water into a flask, react at 90-100°C for 1h, then cool to 60°C, then add 12-15 parts by weight of N-β-(aminoethyl)-ɤ-aminopropylmethyldimethoxysilane coupling agent, 5-6 parts by weight of vinyltrimethoxysilane and 0.3-0.5 parts by weight of tetramethylammonium hydroxide, heat to 120°C and react for 2h, the result is recorded as the reaction component; Step 2: Cool the reaction components to 80°C and evacuate for 30 minutes, then add 200-300 parts by weight of isopropanol and stir to react for 30 minutes, add glacial acetic acid to adjust the pH value to 6, then add 38-40 parts by weight of epichlorohydrin, stir evenly and place at 70°C to react for 2 hours to obtain an organic waterproofing agent.

2. The bio-based lightweight gypsum board according to claim 1, characterized in that: In S1, the drying method is to place in an oven at 45°C for 2 hours, and in S2, the drying method is to place in an oven at 50°C for 1 hour.

3. The bio-based lightweight gypsum board according to claim 1, characterized in that: The preparation method of the silane coupling agent solution is: mixing the silane coupling agent KH-560 and anhydrous ethanol in a weight ratio of 1:10, stirring at a stirring speed of 500-600 r / min for 10 minutes, and obtaining the silane coupling agent solution.

4. The bio-based lightweight gypsum board according to claim 1, characterized in that: In step 2, the stirring speed of the stirring reaction is 200 r / min, and the stirring operation for uniform stirring is 500 r / min for 5 minutes.

5. The method for preparing a bio-based lightweight gypsum board according to any one of claims 1 to 4, characterized in that: The preparation method comprises the following steps: Step 1, surface sulfonated modified bamboo fiber, alkalized abaca fiber and modified straw ash are mixed in equal weight ratios, stirred at a stirring speed of 200-300 r / min for 10 minutes, and recorded as a bio-based component, and a silane coupling agent solution with a weight of 20% of the bio-based component is evenly sprayed on the surface of the bio-based component, and the result is recorded as a modified bio-based component; Step 2, weighing 3-5 parts by weight of an organic waterproofing agent, 2-3 parts by weight of sodium dodecylbenzene sulfonate and 100 parts by weight of distilled water, mixing and stirring to disperse, and the obtained mixture is recorded as a dispersed component; Step 3: Mix 50 parts by weight of modified bio-based components, 80 parts by weight of dispersed components and 150 parts by weight of desulfurized gypsum powder, stir at a stirring speed of 200 r / min for 30 minutes, and then pour into a mold for hardening. The result after demolding is a bio-based lightweight gypsum board.

6. The method for preparing a bio-based lightweight gypsum board according to claim 5, characterized in that: In step 2, the stirring and dispersing operation is to stir at a stirring speed of 300 r / min for 5 minutes, and in step 3, the hardening time is 2 hours.

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