Modified reinforced gypsum material as well as preparation method and application thereof

Abstract

The invention discloses a modified reinforced gypsum material as well as a preparation method and application thereof. Comprising the following steps: uniformly mixing a modified acrylic emulsion, deionized water, hydroxypropyl methyl cellulose, a defoaming agent and a thickening agent, then adding gypsum powder, stirring and curing to obtain the modified reinforced gypsum material which is applicable to the field of buildings. The preparation method has the beneficial effects that secondary modified titanium dioxide is introduced into the modified acrylic emulsion, so that the comprehensive performance of the gypsum material is effectively enhanced.

Description

Technical Field

[0001] This invention belongs to the field of gypsum material technology, specifically relating to a modified and reinforced gypsum material, its preparation method, and its application. Background Technology

[0002] Gypsum, as a traditional building material, is widely used in building decoration and wall materials due to its lightweight, fire-resistant, and environmentally friendly properties.

[0003] However, ordinary gypsum materials suffer from poor mechanical properties, insufficient water resistance, and limited flame retardancy, severely restricting their application in high-performance buildings. Current technologies often improve the mechanical properties of gypsum by adding fibers or polymer emulsions, but these methods often struggle to balance reinforcement effectiveness with material cost, and offer limited improvement in water resistance and flame retardancy. For example, while polymer-modified gypsum can improve flexural strength, its water absorption remains high, making it prone to softening and failure in long-term humid environments. Furthermore, while the addition of traditional flame retardants (such as aluminum hydroxide or halogenated flame retardants) can improve flame retardancy, it may reduce the material's mechanical properties or cause environmental pollution. In addition, the direct addition of inorganic nanoparticles (such as titanium dioxide) is prone to uneven dispersion, leading to insufficient interfacial bonding and failing to fully exert its reinforcing effect.

[0004] Therefore, in order to solve the above problems, the present invention provides a modified reinforced gypsum material, its preparation method and application. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a modified reinforced gypsum material, its preparation method, and its application.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A modified reinforced gypsum material comprises the following components: by weight, 100-120 parts gypsum powder, 10-15 parts modified acrylic emulsion, 40-60 parts deionized water, 1-2 parts hydroxypropyl methylcellulose, 0.1-0.2 parts defoamer, and 0.3-0.5 parts thickener.

[0008] In a more optimized manner, the preparation process of the modified acrylic emulsion is as follows:

[0009] A1: Add titanium dioxide to hydrochloric acid solution, stir at room temperature for 4-5 h, wash and dry to obtain pretreated titanium dioxide, then transfer to toluene, add 3-methacryloxypropyltrimethoxysilane, stir and ultrasonically disperse at 40 °C for 40-50 min, then raise the temperature to 80 °C, reflux for 24 h, filter, wash and dry to obtain primary modified titanium dioxide;

[0010] A2: Mix the modifier, thionyl chloride, and N,N-dimethylformamide, raise the temperature to 70-75℃, react for 3-4 hours, rotary evaporate, dry, and then add it together with the primary modified titanium dioxide into chloroform. Add 4-dimethylaminopyridine, react at 60-70℃ for 2-3 hours, wash, and dry to obtain secondary modified titanium dioxide.

[0011] A3: Mix the emulsifier with deionized water, then add methyl methacrylate, butyl acrylate, acrylic acid, hydroxyethyl methacrylate, trimethylolpropane trimethacrylate, and secondary modified titanium dioxide. Stir at high speed for 30-40 minutes to form a pre-emulsion. Then, under a protective atmosphere, add a portion of the pre-emulsion to the reactor, raise the temperature to 70-80℃, slowly add ammonium persulfate solution, and then add the remaining pre-emulsion and ammonium persulfate solution dropwise over 2-3 hours. Continue the reaction for 1-2 hours, cool to 40-50℃, and adjust the pH to 7-8. Filter and discharge to obtain a modified acrylic emulsion.

[0012] In this scheme, the hydroxyl groups on the surface of titanium dioxide are first activated under acidic conditions. Then, a silane coupling agent (3-methacryloyloxypropyltrimethoxysilane) is refluxed in toluene to graft double-bonded functional groups onto the surface, resulting in primary modified titanium dioxide. Subsequently, a modifier containing phosphorus-phenanthrene and triazole structures is acylated using thionyl chloride, and then esterified with the active groups on the surface of the primary modified titanium dioxide in chloroform to introduce flame-retardant functional groups, forming secondary modified titanium dioxide. Finally, through emulsion polymerization, methacrylate monomers are pre-emulsified with the secondary modified titanium dioxide under the action of an emulsifier. Using ammonium persulfate as an initiator, free radical copolymerization is carried out at 70-80℃, so that the titanium dioxide nanoparticles are uniformly dispersed in the acrylic polymer network, while retaining the reactive groups on the surface, ultimately forming an organic-inorganic hybrid modified acrylic emulsion with both reinforcing and flame-retardant functions. The structure of the secondary modified titanium dioxide is as follows:

[0013]

[0014] In a more optimized manner, the raw materials for preparing the primary modified titanium dioxide include the following components: by weight, 10-12 parts titanium dioxide, 40-50 parts hydrochloric acid solution, 0.3-0.5 parts 3-methacryloyloxypropyltrimethoxysilane, and 50-60 parts toluene; wherein the concentration of the hydrochloric acid solution is 1-2 mol / L.

[0015] In a more optimized manner, the raw materials for preparing the secondary modified titanium dioxide include the following components: by weight, 5-8 parts modifier, 30-40 parts thionyl chloride, 1-2 parts N,N-dimethylformamide, 50-60 parts primary modified titanium dioxide, 60-80 parts chloroform, and 0.5-0.8 parts 4-dimethylaminopyridine.

[0016] In a more optimized manner, the raw materials for preparing the modified acrylic emulsion include the following components: by weight, 2-3 parts emulsifier, 100-120 parts deionized water, 40-60 parts methyl methacrylate, 20-30 parts butyl acrylate, 2-5 parts acrylic acid, 1-3 parts hydroxyethyl methacrylate, 1-2 parts trimethylolpropane trimethacrylate, 1-5 parts secondary modified titanium dioxide, and 1-2 parts ammonium persulfate solution; wherein the concentration of the ammonium persulfate solution is 2-3 wt%.

[0017] In a more optimized manner, the preparation process of the modifier is as follows: 3-amino-1,2,4-triazole-5-carboxylic acid is mixed with anhydrous ethanol, the temperature is raised to 40-50°C, and the mixture is stirred until completely dissolved. Then, 2-thiophenecarboxaldehyde is slowly added dropwise, the temperature is raised to 80°C, and the mixture is refluxed and stirred for 10-12 hours. Subsequently, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) is added, and the mixture is stirred at 80°C for another 12 hours. After the reaction is completed, the mixture is filtered, washed, and dried to obtain the modifier.

[0018] In the scheme, the amino group of 3-amino-1,2,4-triazole-5-carboxylic acid and the aldehyde group of 2-thiophenecarboxaldehyde are first condensed in ethanol to form a Schiff base, generating an imine intermediate containing a triazole ring and a thiophene group. Subsequently, the PH bond of the Schiff base DOPO undergoes a nucleophilic addition reaction, with the phosphorus atom attacking the carbon atom of the imine, causing the PH bond to break and forming a PC bond, ultimately yielding a hybrid modifier containing a triazole nitrogen heterocycle, a thiophene conjugated structure, and a phosphorus-phenanthroline ring.

[0019] In a more optimized manner, the raw materials for preparing the modifier include the following components: by weight, 3-4 parts of 3-amino-1,2,4-triazole-5-carboxylic acid, 200-250 parts of anhydrous ethanol, 4-5 parts of 2-thiophenecarboxaldehyde, and 8-9 parts of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide.

[0020] A more optimized method for preparing a modified reinforced gypsum material includes the following process: mixing modified acrylic emulsion, deionized water, hydroxypropyl methylcellulose, defoamer, and thickener evenly, then adding gypsum powder, stirring and curing to obtain the modified reinforced gypsum material.

[0021] This invention provides the application of a modified reinforced gypsum material as described in the above technical solution, or a modified reinforced gypsum material prepared according to the preparation method described in the above technical solution, in the construction field.

[0022] The beneficial effects of this invention are:

[0023] Firstly, the modified acrylic emulsion constructs an organic-inorganic hybrid system. After activation with hydrochloric acid, titanium dioxide generates abundant hydroxyl groups on its surface. Double-bonded functional groups are grafted onto it using a silane coupling agent (3-methacryloyloxypropyltrimethoxysilane) (primary modification), enabling it to react with organic monomers. Further surface activity is optimized through esterification with a modifier containing a specific structure (secondary modification). Finally, the secondary modified titanium dioxide is uniformly dispersed in a polymer network formed by monomers such as methyl methacrylate and butyl acrylate via emulsion polymerization. The inorganic nanoparticles (titanium dioxide) act as a rigid reinforcing phase, effectively inhibiting polymer chain slippage, while the organic polymer chains transfer stress through flexible connections. Together, they reduce microcracks during the gypsum hardening process, improving the overall mechanical properties of the material.

[0024] Secondly, the modified acrylic emulsion in this design incorporates multiple flame-retardant groups. It contains triazole nitrogen heterocycles, a thiophene conjugated structure, and a phosphaphenanthrene ring. The triazole ring releases inert gases such as nitrogen during combustion, diluting the concentration of combustible gases and oxygen. The phosphaphenanthrene ring decomposes upon heating to generate phosphoric acid, forming a flame-retardant char layer covering the material surface, blocking heat and oxygen transfer. The thiophene conjugated system enhances the polymer's thermal stability and slows down the decomposition rate at high temperatures. These multiple groups synergistically endow the gypsum material with excellent flame-retardant properties.

[0025] Thirdly, modified acrylic emulsions improve the interfacial structure of gypsum. The polymer molecular chains in the emulsion exhibit good compatibility with gypsum particles. During the gypsum curing process, the polymer can fill the pores between gypsum crystals, forming a continuous organic film. This film not only reduces the channels for water penetration but also lowers the contact area between gypsum and water, thereby inhibiting the hydration and dissolution of gypsum and improving the material's water resistance. Furthermore, crosslinking agents in the emulsion system (such as trimethylolpropane trimethacrylate) enhance the crosslinking density of the polymer network, making the structure more stable. Detailed Implementation

[0026] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0027] Example 1: A method for preparing a modified reinforced gypsum material, comprising the following process: mixing 10 parts of modified acrylic emulsion, 40 parts of deionized water, 1 part of hydroxypropyl methylcellulose, 0.1 parts of defoamer, and 0.3 parts of thickener evenly, then adding 100 parts of gypsum powder, curing at room temperature for 3 hours, and then curing at 70°C for 12 hours to obtain the modified reinforced gypsum material;

[0028] The preparation process of the modified acrylic emulsion is as follows:

[0029] A1: 10 parts of titanium dioxide were added to 40 parts of hydrochloric acid solution (2 mol / L), stirred at room temperature for 4 h, washed, and dried to obtain pretreated titanium dioxide. Then, it was transferred to 50 parts of toluene, and 0.3 parts of 3-methacryloyloxypropyltrimethoxysilane were added. The mixture was stirred and ultrasonically dispersed at 40 °C for 40 min. Then, the temperature was raised to 80 °C and refluxed for 24 h. After filtration, washing, and drying, primary modified titanium dioxide was obtained.

[0030] A2: Mix 5 parts of modifier, 30 parts of thionyl chloride, and 1 part of N,N-dimethylformamide, raise the temperature to 70°C, react for 3 hours, rotary evaporate, dry, and then add it together with 50 parts of primary modified titanium dioxide to 60 parts of chloroform. Add 0.5 parts of 4-dimethylaminopyridine, react at 60°C for 2 hours, wash, and dry to obtain secondary modified titanium dioxide.

[0031] A3: Mix 2 parts of emulsifier with 100 parts of deionized water, then add 40 parts of methyl methacrylate, 20 parts of butyl acrylate, 2 parts of acrylic acid, 1 part of hydroxyethyl methacrylate, 1 part of trimethylolpropane trimethacrylate, and 1 part of secondary modified titanium dioxide. Stir at high speed for 30 minutes to form a pre-emulsion. Then, under a protective atmosphere, add a portion of the pre-emulsion to the reactor, raise the temperature to 70°C, slowly add ammonium persulfate solution, and then add the remaining pre-emulsion and ammonium persulfate solution (total 1 part, concentration 2wt%) dropwise over 2 hours. Continue the reaction for 1 hour, cool to 40°C, adjust the pH to 7, filter, and discharge to obtain a modified acrylic emulsion.

[0032] The preparation process of the modifier is as follows: 3 parts of 3-amino-1,2,4-triazole-5-carboxylic acid are mixed with 200 parts of anhydrous ethanol, the temperature is raised to 40°C, and the mixture is stirred until completely dissolved. Then, 4 parts of 2-thiophenecarboxaldehyde are slowly added dropwise, the temperature is raised to 80°C, and the mixture is refluxed and stirred for 10 hours. Subsequently, 8 parts of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide are added, and the mixture is stirred at 80°C for 12 hours. After the reaction is completed, the mixture is filtered, washed, and dried to obtain the modifier.

[0033] Example 2: A method for preparing a modified reinforced gypsum material, comprising the following process: mixing 15 parts of modified acrylic emulsion, 60 parts of deionized water, 2 parts of hydroxypropyl methylcellulose, 0.2 parts of defoamer, and 0.5 parts of thickener evenly, then adding 120 parts of gypsum powder, curing at room temperature for 3 hours, and then curing at 70°C for 12 hours to obtain the modified reinforced gypsum material;

[0034] The preparation process of the modified acrylic emulsion is as follows:

[0035] A1: 12 parts of titanium dioxide were added to 50 parts of hydrochloric acid solution (2 mol / L), stirred at room temperature for 5 h, washed, and dried to obtain pretreated titanium dioxide. Then, it was transferred to 60 parts of toluene, and 0.5 parts of 3-methacryloyloxypropyltrimethoxysilane were added. The mixture was stirred and ultrasonically dispersed at 40 °C for 50 min. Then, the temperature was raised to 80 °C and refluxed for 24 h. After filtration, washing, and drying, primary modified titanium dioxide was obtained.

[0036] A2: Mix 8 parts of modifier, 40 parts of thionyl chloride, and 2 parts of N,N-dimethylformamide, raise the temperature to 75°C, react for 4 hours, rotary evaporate, dry, and then add it together with 60 parts of primary modified titanium dioxide to 80 parts of chloroform. Add 0.8 parts of 4-dimethylaminopyridine, react at 70°C for 3 hours, wash, and dry to obtain secondary modified titanium dioxide.

[0037] A3: Mix 3 parts emulsifier with 120 parts deionized water, then add 60 parts methyl methacrylate, 30 parts butyl acrylate, 5 parts acrylic acid, 3 parts hydroxyethyl methacrylate, 2 parts trimethylolpropane trimethacrylate, and 5 parts secondary modified titanium dioxide. Stir at high speed for 40 minutes to form a pre-emulsion. Then, under a protective atmosphere, add a portion of the pre-emulsion to the reactor, raise the temperature to 80°C, slowly add ammonium persulfate solution, and then add the remaining pre-emulsion and ammonium persulfate solution (total 2 parts, concentration 2wt%) dropwise over 3 hours. Continue the reaction for 2 hours, cool to 50°C, adjust the pH to 8, filter, and discharge to obtain a modified acrylic emulsion.

[0038] The preparation process of the modifier is as follows: 4 parts of 3-amino-1,2,4-triazole-5-carboxylic acid are mixed with 250 parts of anhydrous ethanol, the temperature is raised to 50°C, and the mixture is stirred until completely dissolved. Then, 5 parts of 2-thiophenecarboxaldehyde are slowly added dropwise, the temperature is raised to 80°C, and the mixture is refluxed and stirred for 12 hours. Subsequently, 9 parts of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide are added, and the mixture is stirred at 80°C for another 12 hours. After the reaction is completed, the mixture is filtered, washed, and dried to obtain the modifier.

[0039] Example 3: A method for preparing a modified reinforced gypsum material, comprising the following process: mixing 12.5 parts of modified acrylic emulsion, 50 parts of deionized water, 1.5 parts of hydroxypropyl methylcellulose, 0.15 parts of defoamer, and 0.4 parts of thickener evenly, then adding 110 parts of gypsum powder, curing at room temperature for 3 hours, and then curing at 70°C for 12 hours to obtain the modified reinforced gypsum material;

[0040] The preparation process of the modified acrylic emulsion is as follows:

[0041] A1: 11 parts of titanium dioxide were added to 45 parts of hydrochloric acid solution (2 mol / L), stirred at room temperature for 4.5 h, washed, and dried to obtain pretreated titanium dioxide. Then, it was transferred to 55 parts of toluene, and 0.4 parts of 3-methacryloyloxypropyltrimethoxysilane were added. The mixture was stirred and ultrasonically dispersed at 40 °C for 45 min. Then, the temperature was raised to 80 °C and refluxed for 24 h. After filtration, washing, and drying, primary modified titanium dioxide was obtained.

[0042] A2: Mix 6.5 parts of modifier, 35 parts of thionyl chloride, and 1.5 parts of N,N-dimethylformamide, raise the temperature to 72°C, react for 3.5 h, rotary evaporate, dry, and then add together with 55 parts of primary modified titanium dioxide to 70 parts of chloroform. Add 0.65 parts of 4-dimethylaminopyridine, react at 65°C for 2.5 h, wash, and dry to obtain secondary modified titanium dioxide;

[0043] A3: Mix 2.5 parts of emulsifier with 110 parts of deionized water, then add 50 parts of methyl methacrylate, 25 parts of butyl acrylate, 3.5 parts of acrylic acid, 2 parts of hydroxyethyl methacrylate, 1.5 parts of trimethylolpropane trimethacrylate, and 3 parts of secondary modified titanium dioxide. Stir at high speed for 35 minutes to form a pre-emulsion. Then, under a protective atmosphere, add a portion of the pre-emulsion to the reactor, raise the temperature to 75°C, slowly add ammonium persulfate solution, and then add the remaining pre-emulsion and ammonium persulfate solution (total 1.5 parts, concentration 2wt%) dropwise over 2.5 hours. Continue the reaction for 1.5 hours, cool to 45°C, adjust the pH to 7.5, filter, and discharge to obtain a modified acrylic emulsion.

[0044] The preparation process of the modifier is as follows: 3.5 parts of 3-amino-1,2,4-triazole-5-carboxylic acid and 225 parts of anhydrous ethanol are mixed, the temperature is raised to 45°C, and the mixture is stirred until completely dissolved. Then, 4.5 parts of 2-thiophenecarboxaldehyde are slowly added dropwise, the temperature is raised to 80°C, and the mixture is refluxed and stirred for 11 hours. Subsequently, 8.5 parts of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide are added, and the mixture is stirred at 80°C for another 12 hours. After the reaction is completed, the mixture is filtered, washed, and dried to obtain the modifier.

[0045] Comparative Example 1: No modified titanium dioxide was introduced, as follows:

[0046] A method for preparing a modified reinforced gypsum material includes the following process: mixing 12.5 parts of acrylic emulsion, 50 parts of deionized water, 1.5 parts of hydroxypropyl methylcellulose, 0.15 parts of defoamer, and 0.4 parts of thickener evenly, then adding 110 parts of gypsum powder, curing at room temperature for 3 hours, and then curing at 70°C for 12 hours to obtain the modified reinforced gypsum material;

[0047] The preparation process of acrylic emulsion is as follows:

[0048] 2.5 parts of emulsifier were mixed with 110 parts of deionized water, and then 50 parts of methyl methacrylate, 25 parts of butyl acrylate, 3.5 parts of acrylic acid, 2 parts of hydroxyethyl methacrylate, and 1.5 parts of trimethylolpropane trimethacrylate were added. The mixture was stirred at high speed for 35 minutes to form a pre-emulsion. Then, under a protective atmosphere, a portion of the pre-emulsion was added to a reaction vessel, the temperature was raised to 75°C, and ammonium persulfate solution was slowly added. Then, the remaining pre-emulsion and ammonium persulfate solution (total 1.5 parts, concentration 2wt%) were added dropwise over 2.5 hours. The reaction was continued for 1.5 hours, then the temperature was lowered to 45°C, the pH was adjusted to 7.5, and the mixture was filtered to obtain an acrylic emulsion.

[0049] Comparative Example 2: Pure gypsum sample, as follows: Deionized water and gypsum powder were mixed and stirred at 1500 rpm for 5 minutes. The mixture was then poured into a mold and cured at room temperature for 2 hours, followed by curing in an oven at 80°C for 12 hours.

[0050] Testing experiment:

[0051] (1) The flexural and compressive strengths of the modified reinforced gypsum materials obtained in the examples and comparative examples were tested according to standard GB / T17669.3-1999;

[0052] (2) The water absorption rate of the modified reinforced gypsum material obtained according to the test examples and comparative examples in JC / T698-2010;

[0053] (3) The limiting oxygen index of the modified reinforced gypsum materials obtained in the examples and comparative examples was detected using an oxygen index meter; the data are shown in the table below:

[0054]

[0055] Conclusion: This invention significantly improves the mechanical properties, water resistance, and flame retardancy of gypsum materials by introducing modified acrylic emulsion. The flexural strengths of Examples 1 to 3 reached 10.1 MPa, 9.9 MPa, and 10.8 MPa, respectively, and the compressive strengths were 15.8 MPa, 15.6 MPa, and 16.7 MPa, respectively, all significantly higher than Comparative Example 1 (without modified titanium dioxide) and Comparative Example 2 (pure gypsum sample). Regarding water resistance, the water absorption rate of the examples was only 16.4%-16.7%, far lower than 25.6% of Comparative Example 1 and 29.9% of Comparative Example 2. Furthermore, the oxygen index of the examples reached 30%-32%, indicating excellent flame retardant properties, while the oxygen indices of Comparative Examples 1 and 2 were only 25.2% and 22.1%, respectively.

[0056] In summary, these data fully demonstrate the reinforcing effect of the introduction of secondary modified titanium dioxide into the modified acrylic emulsion on gypsum materials, and the significant improvement in material performance due to the synergistic effect of multiple flame-retardant groups. Therefore, this invention provides a modified reinforced gypsum material with high strength, water resistance, and flame retardancy, suitable for wide applications in the construction field.

[0057] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0058] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, they should all fall within the protection scope of the present invention.

Claims

1. A modified reinforced gypsum material, characterized in that, It includes the following components by weight: 100-120 parts gypsum powder, 10-15 parts modified acrylic emulsion, 40-60 parts deionized water, 1-2 parts hydroxypropyl methylcellulose, 0.1-0.2 parts defoamer, and 0.3-0.5 parts thickener.

2. The modified reinforced gypsum material according to claim 1, characterized in that, The preparation process of the modified acrylic emulsion is as follows: A1: Add titanium dioxide to hydrochloric acid solution, stir at room temperature for 4-5 h, wash and dry to obtain pretreated titanium dioxide, then transfer to toluene, add 3-methacryloxypropyltrimethoxysilane, stir and ultrasonically disperse at 40 °C for 40-50 min, then raise the temperature to 80 °C, reflux for 24 h, filter, wash and dry to obtain primary modified titanium dioxide; A2: Mix the modifier, thionyl chloride, and N,N-dimethylformamide, raise the temperature to 70-75℃, react for 3-4 hours, rotary evaporate, dry, and then add it together with the primary modified titanium dioxide into chloroform. Add 4-dimethylaminopyridine, react at 60-70℃ for 2-3 hours, wash, and dry to obtain secondary modified titanium dioxide. A3: Mix the emulsifier with deionized water, then add methyl methacrylate, butyl acrylate, acrylic acid, hydroxyethyl methacrylate, trimethylolpropane trimethacrylate, and secondary modified titanium dioxide. Stir at high speed for 30-40 minutes to form a pre-emulsion. Then, under a protective atmosphere, add a portion of the pre-emulsion to the reactor, raise the temperature to 70-80℃, slowly add ammonium persulfate solution, and then add the remaining pre-emulsion and ammonium persulfate solution dropwise over 2-3 hours. Continue the reaction for 1-2 hours, cool to 40-50℃, and adjust the pH to 7-8. Filter and discharge to obtain a modified acrylic emulsion.

3. The modified reinforced gypsum material according to claim 2, characterized in that, The raw materials for preparing the primary modified titanium dioxide include the following components: by weight, 10-12 parts titanium dioxide, 40-50 parts hydrochloric acid solution, 0.3-0.5 parts 3-methacryloyloxypropyltrimethoxysilane, and 50-60 parts toluene; wherein the concentration of the hydrochloric acid solution is 1-2 mol / L.

4. The modified reinforced gypsum material according to claim 2, characterized in that, The raw materials for preparing the secondary modified titanium dioxide include the following components: by weight, 5-8 parts modifier, 30-40 parts thionyl chloride, 1-2 parts N,N-dimethylformamide, 50-60 parts primary modified titanium dioxide, 60-80 parts chloroform, and 0.5-0.8 parts 4-dimethylaminopyridine.

5. The modified reinforced gypsum material according to claim 2, characterized in that, The modified acrylic emulsion is prepared from the following raw materials: by weight, 2-3 parts emulsifier, 100-120 parts deionized water, 40-60 parts methyl methacrylate, 20-30 parts butyl acrylate, 2-5 parts acrylic acid, 1-3 parts hydroxyethyl methacrylate, 1-2 parts trimethylolpropane trimethacrylate, 1-5 parts secondary modified titanium dioxide, and 1-2 parts ammonium persulfate solution; wherein the concentration of the ammonium persulfate solution is 2-3 wt%.

6. The modified reinforced gypsum material according to claim 2, characterized in that, The preparation process of the modifier is as follows: 3-amino-1,2,4-triazole-5-carboxylic acid is mixed with anhydrous ethanol, the temperature is raised to 40-50℃, and the mixture is stirred until completely dissolved. Then, 2-thiophenecarboxaldehyde is slowly added dropwise, the temperature is raised to 80℃, and the mixture is refluxed and stirred for 10-12 hours. Subsequently, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is added, and the mixture is stirred at 80℃ for another 12 hours. After the reaction is completed, the mixture is filtered, washed, and dried to obtain the modifier.

7. The modified reinforced gypsum material according to claim 6, characterized in that, The raw materials for preparing the modifier include the following components: by weight, 3-4 parts of 3-amino-1,2,4-triazole-5-carboxylic acid, 200-250 parts of anhydrous ethanol, 4-5 parts of 2-thiophenecarboxaldehyde, and 8-9 parts of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide.

8. A method for preparing a modified reinforced gypsum material according to any one of claims 1-7, characterized in that, The process includes the following steps: mixing modified acrylic emulsion, deionized water, hydroxypropyl methylcellulose, defoamer, and thickener evenly, then adding gypsum powder, stirring and curing to obtain modified reinforced gypsum material.

9. The application of a modified reinforced gypsum material according to any one of claims 1-7 in the construction field.

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