Lightweight high-strength fiber gypsum board based on alpha-semi-hydrated gypsum and preparation method of lightweight high-strength fiber gypsum board

Abstract

The invention belongs to the technical field of fiber plasterboards, and discloses a light high-strength fiber plasterboard based on alpha-semi-hydrated gypsum and a preparation method of the light high-strength fiber plasterboard. The raw materials comprise alpha-semi-hydrated gypsum, a thixotropic agent, a light filler, polypropylene fibers, glass fibers, a titanate coupling agent and water. The main raw material alpha-semi-hydrated gypsum is prepared from phosphogypsum as a raw material through the composite crystal modifier under the normal pressure condition, the crystal is in a hexagonal short column shape, the crystal face is complete, the length-diameter ratio is about 1, the mechanical property is excellent, and the prepared gypsum board is high in compressive strength and breaking strength. In addition, the coupling agent is used for modifying the composite fiber, so that the hydrophobic property of the gypsum board is improved, meanwhile, the compatibility of the fiber and the alpha-semi-hydrated gypsum is also improved, and the mechanical property of the gypsum board is further improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fiber gypsum board, in particular to a lightweight high-strength fiber gypsum board based on alpha-hemihydrate gypsum and a preparation method thereof. BACKGROUND

[0002] Traditional gypsum board mainly uses beta-hemihydrate gypsum as the base material, which has a loose crystal structure, a large specific surface area, a fast hydration speed, but a low hardening body strength. The beta-hemihydrate gypsum is formed by heating and dehydrating dihydrate gypsum under normal pressure drying conditions, and its compressive strength is usually only 3-5 MPa, and its flexural strength is less than 3 MPa, which is difficult to meet the needs of high-end buildings. The gypsum board prepared from beta-hemihydrate gypsum has the following significant defects: (1) insufficient mechanical properties: high density and low strength, prone to cracks or damage when impacted by external forces, and limited load-bearing capacity; (2) poor weather resistance: sensitive to humidity, prone to deformation and mold in a humid environment for a long time, especially in high-humidity areas such as kitchens and bathrooms; (3) limited construction performance: high porosity of the hardened body due to large water requirement of the slurry, and short setting time, which is not conducive to mechanized construction; (4) single function: although it has certain heat and sound insulation effects, its performance is not outstanding compared with other modern materials, and it is difficult to meet the needs of special scenarios.

[0003] Therefore, how to provide a lightweight high-strength gypsum board is of great significance to the development of the building industry. SUMMARY

[0004] The present application relates to the technical field of fiber gypsum board, in particular to a lightweight high-strength fiber gypsum board based on alpha-hemihydrate gypsum and a preparation method thereof.

[0005] In order to achieve the above-mentioned purpose of the application, the present application provides the following technical solutions: The present application provides a lightweight high-strength fiber gypsum board based on alpha-hemihydrate gypsum, which comprises the following raw materials in mass fraction: alpha-hemihydrate gypsum 70-80 parts, thixotropic agent 1-5 parts, lightweight filler 5-20 parts, polypropylene fiber 1-10 parts, glass fiber 1-10 parts, titanate coupling agent 1-5 parts, and water 20-35 parts; The preparation method of the alpha-hemihydrate gypsum comprises the following steps: Mixing sodium sulfate, dodecyltrimethylammonium bromide and water, and then drying to obtain a composite crystal modifier; mixing the composite crystal modifier and water to obtain a crystal modifier solution, and then adding phosphogypsum to react to obtain alpha-hemihydrate gypsum.

[0006] Preferably, the mass ratio of sodium sulfate and dodecyltrimethylammonium bromide is 5-30 g: 0.05-2 g.

[0007] Preferably, the ratio of the composite crystal modifier to water is 0.1~5g:20mL; and the solid-liquid ratio of the phosphogypsum to the crystal modifier solution is 1:1~4.

[0008] Preferably, the reaction temperature is 80~100℃ and the reaction time is 30~120min.

[0009] Preferably, the thixotropic agent is hydroxypropyl methylcellulose.

[0010] Preferably, the lightweight filler is closed-cell perlite and / or lightweight calcium carbonate.

[0011] This invention also provides a method for preparing lightweight high-strength fiber gypsum board based on α-hemihydrate gypsum, comprising the following steps: Titanate coupling agent, polypropylene fiber, glass fiber and water are mixed to obtain modified fiber solution; α-hemihydrate gypsum, thixotropic agent and lightweight filler are added to modified fiber solution to obtain slurry; slurry is poured into mold to form, demolded and cured to obtain lightweight high-strength fiber gypsum board based on α-hemihydrate gypsum.

[0012] As can be seen from the above technical solution, compared with the prior art, the present invention has the following beneficial effects: (1) This invention utilizes high-strength α-hemihydrate gypsum prepared by a specific method as the main raw material for fiber gypsum board, supplemented with thixotropic agents, lightweight fillers, composite fibers, and coupling agents. Through pulping, casting, and curing, lightweight high-strength fiber gypsum board is obtained. The main raw material of this invention, α-hemihydrate gypsum, is prepared from phosphogypsum under normal pressure using a composite crystal modifier. The crystal morphology is hexagonal short prismatic with complete crystal faces and an aspect ratio of approximately 1, exhibiting excellent mechanical properties. The resulting gypsum board has high compressive strength and flexural strength. This invention also uses a coupling agent to modify the composite fibers, improving the hydrophobic properties of the gypsum board and enhancing the compatibility between the fibers and α-hemihydrate gypsum, further improving the mechanical properties of the gypsum board.

[0013] (2) The α-hemihydrate gypsum of the present invention uses phosphogypsum as raw material, realizes the resource utilization of industrial solid waste, reduces the cost of gypsum board, and the preparation method of the present invention is simple and the reaction conditions are mild, making it suitable for large-scale industrial production. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0015] Figure 1 The image shows a SEM image of the α-hemihydrate gypsum prepared in Example 1. Detailed Implementation

[0016] This invention provides a lightweight, high-strength fiber gypsum board based on α-hemihydrate gypsum, comprising the following raw materials in parts by weight: 70-80 parts α-hemihydrate gypsum, 1-5 parts thixotropic agent, 5-20 parts lightweight filler, 1-10 parts polypropylene fiber, 1-10 parts glass fiber, 1-5 parts titanate coupling agent, and 20-35 parts water.

[0017] In this invention, the thixotropic agent is preferably hydroxypropyl methylcellulose.

[0018] In this invention, the lightweight filler is preferably closed-cell perlite and / or lightweight calcium carbonate, more preferably closed-cell perlite or lightweight calcium carbonate, and even more preferably lightweight calcium carbonate; the particle size of the closed-cell perlite is preferably 100~500μm, more preferably 150~300μm, and even more preferably 200μm; the particle size of the lightweight calcium carbonate is preferably 600~1250 mesh, more preferably 800~1250 mesh, and even more preferably 1250 mesh.

[0019] In this invention, the length of the polypropylene fiber is preferably 5-8 mm, more preferably 5-7 mm, and even more preferably 5 mm, and the diameter is preferably 10-40 μm, more preferably 15-30 μm, and even more preferably 20 μm.

[0020] In this invention, the length of the glass fiber is preferably 3-10 mm, more preferably 4-8 mm, and even more preferably 5 mm, and the diameter is preferably 10-20 μm, more preferably 15-20 μm, and even more preferably 20 μm.

[0021] In this invention, the titanate coupling agent is preferably titanate coupling agent 201.

[0022] In this invention, the preparation method of the α-hemihydrate gypsum includes the following steps: Sodium sulfate (Na2SO4), dodecyltrimethylammonium bromide (DTAB), and water are mixed and then dried to obtain a composite crystal modifier. The composite crystal modifier and water are mixed to obtain a crystal modifier solution, which is then added to phosphogypsum and reacted to obtain α-hemihydrate gypsum.

[0023] In this invention, the preferred mass ratio of sodium sulfate to dodecyltrimethylammonium bromide is 5-30g:0.05-2g, more preferably 5g:0.05g, 10g:0.1g, 15g:0.5g, 20g:1g, 25g:1.5g or 30g:2g.

[0024] In this invention, the drying temperature is preferably 40~60℃, and more preferably 40℃, 45℃, 50℃, 55℃ or 60℃.

[0025] In this invention, the preferred ratio of the composite crystal modifier to water is 0.1~5g:20mL, more preferably 0.5g:20mL, 1g:20mL, 2g:20mL, 3g:20mL, 4g:20mL or 5g:20mL.

[0026] In this invention, the solid-liquid ratio of the phosphogypsum and crystal modifier solution is preferably 1:1 to 4, and more preferably 1:1, 1:2, 1:3 or 1:4.

[0027] In this invention, the reaction temperature is preferably 80~100℃, more preferably 80℃, 85℃, 90℃, 95℃ or 100℃; the reaction time is preferably 30~120min, more preferably 30min, 40min, 50min, 60min, 70min, 80min, 90min, 100min, 110min or 120min.

[0028] In this invention, the process after the reaction is completed includes filtration, washing with ethanol, and drying; the drying temperature is preferably 40~60℃, and more preferably 40℃, 45℃, 50℃, 55℃ or 60℃.

[0029] In this invention, the main component contents of the phosphogypsum are shown in Table 1.

[0030] Table 1. Content of main components of phosphogypsum

[0031] This invention also provides a method for preparing lightweight high-strength fiber gypsum board based on α-hemihydrate gypsum, comprising the following steps: Titanate coupling agent, polypropylene fiber, glass fiber and water are mixed to obtain modified fiber solution; α-hemihydrate gypsum, thixotropic agent and lightweight filler are added to modified fiber solution to obtain slurry; slurry is poured into mold to form, demolded and cured to obtain lightweight high-strength fiber gypsum board based on α-hemihydrate gypsum.

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

[0033] Example 1

[0034] This embodiment provides a lightweight, high-strength fiber gypsum board based on α-hemihydrate gypsum, comprising the following raw materials in parts by weight: 78 parts α-hemihydrate gypsum, 3 parts hydroxypropyl methylcellulose, 10 parts light calcium carbonate (800 mesh), 4 parts polypropylene fiber (5 mm in length, 20 μm in diameter), 6 parts glass fiber (5 mm in length, 20 μm in diameter), 2 parts titanate coupling agent 201, and 25 parts water.

[0035] The above-mentioned method for preparing lightweight high-strength fiber gypsum board based on α-hemihydrate gypsum includes the following steps: (1) Add 25g Na2SO4 and 1.5g DTAB to 50mL of deionized water and stir for 30min. After stirring evenly, dry in an oven at 40℃ to constant weight to obtain a composite crystal modifier. Add 26.5g of the composite crystal modifier to a three-necked flask, add 200mL of deionized water, and add the raw material phosphogypsum at a solid-liquid ratio of 1:4. Stir and react at 90℃ for 60min. After the reaction is complete, filter, wash with ethanol, and dry in an oven at 60℃ to obtain α-hemihydrate gypsum. The SEM image of the obtained α-hemihydrate gypsum is shown below. Figure 1 As shown; (2) Mix titanate coupling agent 201, polypropylene fiber, glass fiber and water for 30 min to obtain modified fiber solution; add α-hemihydrate gypsum, hydroxypropyl methylcellulose and light calcium carbonate to modified fiber solution and stir for 30 min to obtain slurry; pour the slurry into the mold and mold it. After demolding for 6 h, allow it to cure naturally at room temperature to obtain lightweight high-strength fiber gypsum board based on α-hemihydrate gypsum.

[0036] The lightweight, high-strength fiber gypsum board based on α-hemihydrate gypsum prepared in this embodiment has a thickness of 9.5 mm, a dry compressive strength of 47.2 MPa, a dry flexural strength of 16.7 MPa, a softening coefficient of 0.78, and a shear force of 1524 N.

[0037] Example 2

[0038] This embodiment provides a lightweight, high-strength fiber gypsum board based on α-hemihydrate gypsum, comprising the following raw materials in parts by weight: 75 parts α-hemihydrate gypsum, 3 parts hydroxypropyl methylcellulose, 6 parts light calcium carbonate (800 mesh), 2 parts polypropylene fiber (5 mm in length, 20 μm in diameter), 2 parts glass fiber (5 mm in length, 20 μm in diameter), 3 parts titanate coupling agent 201, and 22 parts water.

[0039] The above-mentioned method for preparing lightweight high-strength fiber gypsum board based on α-hemihydrate gypsum includes the following steps: (1) Add 15g Na2SO4 and 0.5g DTAB to 50mL of deionized water and stir for 30min. After stirring evenly, dry in an oven at 50℃ to constant weight to obtain composite crystal modifier. Add 15.5g of composite crystal modifier to the reactor, add 200mL of deionized water, and add raw material phosphogypsum at a solid-liquid ratio of 1:1. Stir and react at 80℃ for 90min. After the reaction is completed, filter, wash with ethanol, and dry in an oven at 50℃ to obtain α-hemihydrate gypsum. (2) Mix titanate coupling agent 201, polypropylene fiber, glass fiber and water for 30 min to obtain modified fiber solution; add α-hemihydrate gypsum, hydroxypropyl methylcellulose and light calcium carbonate to modified fiber solution and stir for 30 min to obtain slurry; pour the slurry into the mold and mold it. After demolding for 6 h, allow it to cure naturally at room temperature to obtain lightweight high-strength fiber gypsum board based on α-hemihydrate gypsum.

[0040] The lightweight, high-strength fiber gypsum board based on α-hemihydrate gypsum prepared in this embodiment has a thickness of 9.5 mm, a dry compressive strength of 45.8 MPa, a dry flexural strength of 15.9 MPa, a softening coefficient of 0.79, and a shear force of 1513 N.

[0041] Example 3

[0042] This embodiment provides a lightweight, high-strength fiber gypsum board based on α-hemihydrate gypsum, comprising the following raw materials in parts by weight: 70 parts α-hemihydrate gypsum, 1 part hydroxypropyl methylcellulose, 15 parts light calcium carbonate (1250 mesh), 5 parts polypropylene fiber (5 mm in length, 20 μm in diameter), 1 part glass fiber (5 mm in length, 20 μm in diameter), 1 part titanate coupling agent 201, and 30 parts water.

[0043] The above-mentioned method for preparing lightweight high-strength fiber gypsum board based on α-hemihydrate gypsum includes the following steps: (1) Add 18g Na2SO4 and 1.0g DTAB to 50mL of deionized water and stir for 30min. After stirring evenly, dry in an oven at 55℃ to constant weight to obtain composite crystal modifier. Add 19g of composite crystal modifier to the reactor, add 200mL of deionized water, and add raw material phosphogypsum at a solid-liquid ratio of 1:2. Stir and react at 85℃ for 50min. After the reaction is completed, filter, wash with ethanol, and dry in an oven at 55℃ to obtain α-hemihydrate gypsum. (2) Mix titanate coupling agent 201, polypropylene fiber, glass fiber and water for 30 min to obtain modified fiber solution; add α-hemihydrate gypsum, hydroxypropyl methylcellulose and light calcium carbonate to modified fiber solution and stir for 30 min to obtain slurry; pour the slurry into the mold and mold it. After demolding for 6 h, allow it to cure naturally at room temperature to obtain lightweight high-strength fiber gypsum board based on α-hemihydrate gypsum.

[0044] The lightweight high-strength fiber gypsum board based on α-hemihydrate gypsum prepared in this embodiment has a thickness of 9.5 mm, a dry compressive strength of 44.1 MPa, a dry flexural strength of 15.7 MPa, a softening coefficient of 0.81, and a shear force of 1489 N.

[0045] Example 4

[0046] This embodiment provides a lightweight, high-strength fiber gypsum board based on α-hemihydrate gypsum, comprising the following raw materials in parts by weight: 80 parts α-hemihydrate gypsum, 1 part hydroxypropyl methylcellulose, 12 parts light calcium carbonate (1250 mesh), 8 parts polypropylene fiber (5 mm in length, 20 μm in diameter), 6 parts glass fiber (5 mm in length, 20 μm in diameter), 3 parts titanate coupling agent 201, and 30 parts water.

[0047] The above-mentioned method for preparing lightweight high-strength fiber gypsum board based on α-hemihydrate gypsum includes the following steps: (1) Add 28g Na2SO4 and 2g DTAB to 50mL of deionized water and stir for 30min. After stirring evenly, dry in an oven at 60℃ to constant weight to obtain composite crystal modifier. Add 30g of composite crystal modifier to the reactor, add 200mL of deionized water, and add raw material phosphogypsum at a solid-liquid ratio of 1:4. Stir and react at 100℃ for 40min. After the reaction is completed, filter, wash with ethanol, and dry in an oven at 60℃ to obtain α-hemihydrate gypsum. (2) Mix titanate coupling agent 201, polypropylene fiber, glass fiber and water for 30 min to obtain modified fiber solution; add α-hemihydrate gypsum, hydroxypropyl methylcellulose and light calcium carbonate to modified fiber solution and stir for 30 min to obtain slurry; pour the slurry into the mold and mold it. After demolding for 6 h, allow it to cure naturally at room temperature to obtain lightweight high-strength fiber gypsum board based on α-hemihydrate gypsum.

[0048] The lightweight, high-strength fiber gypsum board based on α-hemihydrate gypsum prepared in this embodiment has a thickness of 9.5 mm, a dry compressive strength of 44.3 MPa, a dry flexural strength of 16 MPa, a softening coefficient of 0.79, and a shear force of 1506 N.

[0049] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A lightweight high strength fibered gypsum board based on a-hemihydrate gypsum, characterized in that, The raw materials include the following mass fractions: Alpha-hemihydrate gypsum 70-80 parts, thixotropic agent 1-5 parts, light filler 5-20 parts, polypropylene fiber 1-10 parts, glass fiber 1-10 parts, titanate coupling agent 1-5 parts, and water 20-35 parts; The preparation method of the alpha-hemihydrate gypsum comprises the following steps: The sodium sulfate, dodecyltrimethylammonium bromide and water are mixed, and then dried to obtain a composite crystal modifier; the composite crystal modifier and water are mixed to obtain a crystal modifier solution, and then the phosphogypsum is added and reacted to obtain alpha-hemihydrate gypsum.

2. A lightweight high strength fiber reinforced gypsum board based on a-hemihydrate gypsum according to claim 1, characterized in that, The mass ratio of the sodium sulfate and dodecyltrimethylammonium bromide is 5-30 g: 0.05-2 g.

3. A lightweight high strength fiber gypsum board based on a-hemihydrate gypsum according to claim 2, characterized in that, The usage ratio of the composite crystal modifier and water is 0.1-5 g: 20 mL; the solid-liquid ratio of the phosphogypsum and the crystal modifier solution is 1: 1-4.

4. A lightweight high strength fiber reinforced gypsum board based on a- hemihydrate gypsum according to claim 3, characterized in that, The reaction temperature is 80-100 DEG C; and the reaction time is 30-120 min.

5. A lightweight high strength fiber plaster board based on a-hemihydrate gypsum according to claim 4, characterized in that, The thixotropic agent is hydroxypropyl methyl cellulose.

6. A lightweight high strength fiber reinforced gypsum board based on α-hemihydrate gypsum according to claim 2, characterized in that, The light filler is closed-cell perlite and / or light calcium carbonate.

7. A process for the production of a lightweight high strength fibrous gypsum board based on α-hemihydrate gypsum according to any one of claims 1 to 6, characterized in that, The method comprises the following steps: The titanate coupling agent, polypropylene fiber, glass fiber and water are mixed to obtain a modified fiber solution; The alpha-hemihydrate gypsum, thixotropic agent and light filler are added into the modified fiber solution to obtain a slurry; the slurry is cast and formed in a mold, and after demolding, curing is performed to obtain a light high-strength fiber gypsum board based on alpha-hemihydrate gypsum.

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