A flame-retardant and environmentally friendly interior wall putty and its preparation method

Abstract

This invention relates to the field of interior wall putty, specifically disclosing a flame-retardant and environmentally friendly interior wall putty. The raw materials, by weight, include: 10-20 parts oxidized starch, 10-20 parts guar gum, 10-15 parts putty-specific adhesive powder, 5-7 parts carboxyl-terminated hyperbranched polyester, 1-3 parts chitosan, 3-5 parts graphene oxide, 3-5 parts hydroxypropyl methylcellulose ether, 3-5 parts starch, 1-3 parts sodium stearate, 1-3 parts sodium hexametaphosphate, 1-3 parts water glass, 1-3 parts borate, 1-3 parts nano-antimony trioxide, 1-5 parts heavy calcium carbonate, 1-3 parts an 8-12% acetic acid aqueous solution, 1-3 parts ethanol, 1-3 parts glycerin, and 0.1-0.3 parts preservative. This invention also discloses a method for preparing the above-mentioned flame-retardant and environmentally friendly interior wall putty. This invention uses the natural material guar gum, which works synergistically with various other materials to effectively enhance the stability and flame retardancy of the system.

Description

Technical Field

[0001] This invention relates to the field of interior wall putty technology, and in particular to a flame-retardant and environmentally friendly interior wall putty and its preparation method. Background Technology

[0002] As an essential building decoration material, interior wall putty has reduced the harm of formaldehyde to people's health in recent years. However, problems such as blistering and cracking of the putty layer often occur. At the same time, putty powder needs to be mixed on-site, which is not only labor-intensive and time-consuming, but also causes secondary pollution at the construction site. The flying dust has a great impact on the construction environment and workers' health. In addition, the flammability of the polymer in interior wall putty also poses a great hidden danger.

[0003] Drawing on the application principle of guar gum in wall coatings, adding guar gum to interior wall putty not only does not contain formaldehyde, but also has a much better cost performance and storage stability than traditional putty, showing excellent application prospects. However, it has the disadvantages of poor bonding strength and insufficient flame retardant performance, which limits its use. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a flame-retardant and environmentally friendly interior wall putty and its preparation method.

[0005] A flame-retardant and environmentally friendly interior wall putty, the raw materials of which include, by weight: 10-20 parts oxidized starch, 10-20 parts guar gum, 10-15 parts putty-specific adhesive powder, 5-7 parts carboxyl-terminated hyperbranched polyester, 1-3 parts chitosan, 3-5 parts graphene oxide, 3-5 parts hydroxypropyl methylcellulose ether, 3-5 parts starch, 1-3 parts sodium stearate, 1-3 parts sodium hexametaphosphate, 1-3 parts water glass, 1-3 parts borate, 1-3 parts nano antimony trioxide, 1-5 parts heavy calcium carbonate, 1-3 parts acetic acid aqueous solution with a weight fraction of 8-12%, 1-3 parts ethanol, 1-3 parts glycerin, and 0.1-0.3 parts preservative.

[0006] Preferably, the molecular weight of the carboxyl-terminated hyperbranched polyester is 1800-2100 g / mol, and the acid value is 200-240 mg KOH / g.

[0007] Preferably, the graphene oxide particle size is 10-20 μm.

[0008] Preferably, the nano-antimony trioxide particles have a particle size of 20-30 μm and a specific surface area of ​​40-50 m². 2 / g.

[0009] Preferably, the preservative is either magnesium oxide or zinc oxide.

[0010] Preferably, the modulus of the water glass is 2-2.5.

[0011] Preferably, the borate is sodium tetraborate.

[0012] Preferably, the particle size of the calcium carbonate is 30-40 μm.

[0013] A method for preparing flame-retardant and environmentally friendly interior wall putty includes the following steps:

[0014] S1. Stir oxidized starch and water for 10-15 minutes at a stirring temperature of 80-90℃. Add glycerol and continue stirring for 15-20 minutes. Add acetic acid aqueous solution (8-12% by mass), chitosan, carboxyl-terminated hyperbranched polyester, ethanol, and graphene oxide. Continue stirring for 10-15 minutes. After the system cools to room temperature, degas under vacuum for 2-3 hours to obtain preform A.

[0015] S2. At room temperature, mix pre-mixed material A, guar gum, hydroxypropyl methylcellulose ether, putty-specific adhesive powder, and preservative, and stir for 10-15 minutes to obtain pre-mixed material B.

[0016] S3. Add starch, sodium stearate, and sodium hexametaphosphate to water and stir at a speed of 500-600 r / min for 10-15 min at a temperature of 50-60℃. Add heavy calcium carbonate and stir for 10-20 min. Cool to room temperature. Add water glass, borate, and nano antimony trioxide and stir at a speed of 1450-1500 r / min for 20-30 min. Reflux at 75-85℃ for 2-8 h. Cool to 20-40℃, adjust the pH to 8-9, stir until homogeneous, and allow to stand for aging for 10-20 h. First, use isopropanol as a solvent for solvent replacement for 5-6 h; then use n-hexane as a solvent for solvent replacement for 5-6 h. Subsequently, dry at 50-60℃ under normal pressure to constant weight. Add pre-mixed material B and stir until homogeneous to obtain flame-retardant and environmentally friendly interior wall putty.

[0017] Beneficial effects:

[0018] Guar gum is derived from natural plants, contains no formaldehyde, and will not pollute the environment or human health. In this invention, the carboxyl-terminated hyperbranched polyester carries a large number of terminal carboxyl groups, which undergo esterification with chitosan and oxidized starch to form a highly branched three-dimensional structure. The molecular chains are not easily entangled, resulting in good bonding with guar gum. The system exhibits high viscosity and pseudoplastic fluid characteristics of a non-Newtonian fluid, which not only improves the water resistance of interior wall putty but also increases its bonding strength, although its flame retardant properties are poor.

[0019] This invention combines two-dimensional sheet graphene oxide with a highly branched three-dimensional structure. Because its molecular chains are not easily entangled, the doping effect of graphene oxide is not only significant, but the combination of the two-dimensional sheet structure of graphene oxide and the three-dimensional hyperbranched structure can significantly improve the stability of interior wall putty. The synergistic system has excellent flame retardancy.

[0020] This invention incorporates borates, which can form aggregates in water glass. After aerogelation, these aggregates combine with the graphene oxide sheet structure, effectively promoting the uniform dispersion of nano-antimony trioxide. This not only improves the gelation quality and enhances waterproof performance, but also transforms into a silicate foam-like heat insulation layer during combustion, exhibiting good flame retardant properties. Furthermore, it is safe, non-toxic, and cost-effective. Sodium stearate reduces the surface energy of small calcium carbonate particles, decreasing the tendency for particle aggregation and improving the dispersion of calcium carbonate in the system, further enhancing the stability of the interior wall putty.

[0021] This invention is not only environmentally friendly, with minimal odor and energy saving, but also effectively enhances the stability of the system in practical applications. It also enhances the flame retardancy and water resistance of the system, improves the performance of interior wall putty, extends its service life, and does not require on-site preparation. The preparation method is simple and suitable for large-scale production applications. Attached Figure Description

[0022] Figure 1 This is a comparison chart of the drying times of flame-retardant and environmentally friendly interior wall putty obtained using Example 5 and Comparative Examples 1-2.

[0023] Figure 2 The image shows a comparison of the bonding strength of flame-retardant and environmentally friendly interior wall putty obtained using Example 5 and Comparative Examples 1-2.

[0024] Figure 3 This is a comparison chart of the moisture absorption rates of flame-retardant and environmentally friendly interior wall putty obtained using Example 5 and Comparative Examples 1-2.

[0025] Figure 4 The graph shows the heat loss rate ratio of the flame-retardant and environmentally friendly interior wall putty obtained using Example 5 and Comparative Examples 1-2.

[0026] Figure 5 This is a comparison chart of the melting rates of flame-retardant and environmentally friendly interior wall putty obtained using Example 5 and Comparative Examples 1-2. Detailed Implementation

[0027] The present invention will be further explained below with reference to specific embodiments.

[0028] The carboxyl-terminated hyperbranched polyester used below was purchased from Wuhan Moulisheng Chemical Co., Ltd.; the graphene oxide used below was purchased from Jiangsu Xianmou Nanotechnology Co., Ltd.; and the putty-specific adhesive powder used below was purchased from Langfang Mouzhen Chemical Co., Ltd.

[0029] Example 1

[0030] A flame-retardant and environmentally friendly interior wall putty and its preparation method include the following steps:

[0031] S1. Stir 10g of oxidized starch and 50g of water for 15 minutes at 90℃. Add 2g of glycerol and continue stirring for 15 minutes. Add 1g of 10% acetic acid, 1g of chitosan, 5g of carboxyl-terminated hyperbranched polyester with a molecular weight of 2100g / mol and an acid value of 240mgKOH / g, 1g of ethanol, and 3g of graphene oxide with a particle size of 20μm. Continue stirring for 15 minutes. After the solution cools to room temperature, degas under vacuum for 2 hours to obtain pre-formulated material A.

[0032] S2. At room temperature, mix pre-mixed material A, 10g guar gum, 3g hydroxypropyl methylcellulose ether, 10g putty-specific adhesive powder, and 0.1g magnesium oxide, and stir for 15 minutes to obtain pre-mixed material B.

[0033] S3. Add 3g starch, 1g sodium stearate, and 1g sodium hexametaphosphate to 10g water and stir at 500 rpm for 15 minutes at 60℃. Add 1g of heavy calcium carbonate with a particle size of 30μm and stir at 500 rpm for 20 minutes. Cool to room temperature. Add 1g water glass with a modulus of 2, 1g sodium tetraborate, and 1g of sodium carbonate with a particle size of 30μm and a specific surface area of ​​50m². 2 / g of nano-antimony trioxide was mixed and stirred at 1450r / min for 30min. The mixture was then heated and refluxed at 75℃ for 2h. After cooling to 40℃, the pH was adjusted to 8, and the mixture was stirred until homogeneous. The mixture was then allowed to stand for aging. After aging, 30g of isopropanol was used as a solvent for solvent replacement for 6h, followed by 20g of n-hexane as a solvent for solvent replacement for 5h. The mixture was then dried at 60℃ under normal pressure to constant weight and added to pre-mixed material B. The mixture was stirred to obtain flame-retardant and environmentally friendly interior wall putty.

[0034] Example 2

[0035] A flame-retardant and environmentally friendly interior wall putty and its preparation method include the following steps:

[0036] S1. Mix 20g of oxidized starch and 100g of water for 15 minutes at 90℃. Add 3g of glycerol and continue stirring for 15 minutes. Add 3g of acetic acid (10% by mass), 3g of chitosan, 7g of carboxyl-terminated hyperbranched polyester with a molecular weight of 2100g / mol and an acid value of 240mgKOH / g, 3g of ethanol, and 5g of graphene oxide with a particle size of 20μm. Continue stirring for 15 minutes. After the solution cools to room temperature, degas under vacuum for 2 hours to obtain pre-formulated material A.

[0037] S2. At room temperature, mix pre-mixed material A, 20g guar gum, 5g hydroxypropyl methylcellulose ether, 15g putty-specific adhesive powder, and 0.3g zinc oxide, and stir for 15 minutes to obtain pre-mixed material B.

[0038] S3. Add 5g starch, 3g sodium stearate, and 3g sodium hexametaphosphate to 20g water and stir at 500 rpm for 15 minutes at 60℃. Add 3g of heavy calcium carbonate with a particle size of 30μm and stir at 500 rpm for 20 minutes. Cool to room temperature. Add 3g water glass with a modulus of 2, 3g sodium tetraborate, and 3g of sodium carbonate with a particle size of 30μm and a specific surface area of ​​50m². 2 / g of nano-antimony trioxide was mixed and stirred at 1450r / min for 30min. The mixture was then heated and refluxed at 75℃ for 2h. After cooling to 40℃, the pH was adjusted to 8, and the mixture was stirred until homogeneous. The mixture was then allowed to stand for aging. After aging, 40g of isopropanol was used as a solvent for solvent replacement for 6h, followed by 30g of n-hexane as a solvent for solvent replacement for 5h. The mixture was then dried at 60℃ under normal pressure to constant weight and added to pre-mixed material B. The mixture was stirred to obtain flame-retardant and environmentally friendly interior wall putty.

[0039] Example 3

[0040] A flame-retardant and environmentally friendly interior wall putty and its preparation method include the following steps:

[0041] S1. Stir 11g of oxidized starch and 80g of water for 15 minutes at 90℃. Add 1.1g of glycerol and continue stirring for 15 minutes. Add 1.1g of acetic acid (10% by mass), 1.1g of chitosan, 5.1g of carboxyl-terminated hyperbranched polyester with a molecular weight of 2100g / mol and an acid value of 240mg KOH / g, 1.1g of ethanol, and 3.1g of graphene oxide with a particle size of 20μm. Continue stirring for 15 minutes. After the solution cools to room temperature, degas under vacuum for 2 hours to obtain pre-processed material A.

[0042] S2. At room temperature, mix pre-mixed material A, 11g guar gum, 3.1g hydroxypropyl methylcellulose ether, 11g putty-specific adhesive powder, and 0.11g magnesium oxide, and stir for 15 minutes to obtain pre-mixed material B.

[0043] S3. Add 3.1g starch, 1.1g sodium stearate, and 1.1g sodium hexametaphosphate to 20g water and stir at 500 rpm for 15 minutes at 60℃. Add 1.1g of heavy calcium carbonate with a particle size of 30μm and stir at 500 rpm for 20 minutes. Cool to room temperature, then add 1.1g water glass with a modulus of 2, 1.1g sodium tetraborate, and 1.1g of sodium carbonate with a particle size of 30μm and a specific surface area of ​​50m².2 / g of nano-antimony trioxide was mixed and stirred at 1450r / min for 30min. The mixture was then heated under reflux at 75℃ for 2h. After cooling to 40℃, the pH was adjusted to 8, and the mixture was stirred until homogeneous. The mixture was then allowed to stand for aging. After aging, 31g of isopropanol was used as a solvent for solvent replacement for 6h, followed by 21g of n-hexane as a solvent for solvent replacement for 5h. The mixture was then dried at 60℃ under normal pressure to constant weight and added to pre-mixed material B. The mixture was stirred to obtain flame-retardant and environmentally friendly interior wall putty.

[0044] Example 4

[0045] A flame-retardant and environmentally friendly interior wall putty and its preparation method include the following steps:

[0046] S1. Stir 19g of oxidized starch and 90g of water for 15 minutes at 90℃. Add 2.9g of glycerol and continue stirring for 15 minutes. Add 2.9g of acetic acid (10% by mass), 2.9g of chitosan, 6.9g of carboxyl-terminated hyperbranched polyester with a molecular weight of 2100g / mol and an acid value of 240mg KOH / g, 2.9g of ethanol, and 4.9g of graphene oxide with a particle size of 20μm. Continue stirring for 15 minutes. After the solution cools to room temperature, degas under vacuum for 2 hours to obtain pre-processed material A.

[0047] S2. Under room temperature conditions, mix pre-mixed material A, 19g guar gum, 4.9g hydroxypropyl methylcellulose ether, 14.9g putty-specific adhesive powder, and 0.29g magnesium oxide, and stir for 15 minutes to obtain pre-mixed material B.

[0048] S3. Add 4.9g starch, 2.9g sodium stearate, and 2.9g sodium hexametaphosphate to 29g water and stir at 500 rpm for 15 minutes at 60℃. Add 2.9g of heavy calcium carbonate with a particle size of 30μm and stir at 500 rpm for 20 minutes. Cool to room temperature. Add 2.9g water glass with a modulus of 2, 2.9g sodium tetraborate, and 2.9g of sodium carbonate with a particle size of 30μm and a specific surface area of ​​50m². 2 / g of nano-antimony trioxide was mixed and stirred at 1450r / min for 30min. The mixture was then heated under reflux at 75℃ for 2h. After cooling to 40℃, the pH was adjusted to 8, and the mixture was stirred until homogeneous. The mixture was then allowed to stand for aging. After aging, 39g of isopropanol was used as a solvent for solvent replacement for 6h, followed by 29g of n-hexane as a solvent for solvent replacement for 5h. The mixture was then dried at 60℃ under normal pressure to constant weight and added to pre-mixed material B. The mixture was stirred to obtain flame-retardant and environmentally friendly interior wall putty.

[0049] Example 5

[0050] A flame-retardant and environmentally friendly interior wall putty and its preparation method include the following steps:

[0051] S1. Mix 15g of oxidized starch with a carboxyl content of 0.25% and 75g of water for 15 minutes at 90℃. Add 2g of glycerol and continue stirring for 15 minutes. Add 2g of acetic acid (10% by mass), 2g of chitosan, 6g of carboxyl-terminated hyperbranched polyester with a molecular weight of 2100g / mol and an acid value of 240mg KOH / g, 2g of ethanol, and 4g of graphene oxide with a particle size of 20μm. Continue stirring for 15 minutes. After the solution cools to room temperature, degas under vacuum for 2 hours to obtain preform A.

[0052] S2. At room temperature, mix pre-mixed material A, 15g guar gum, 4g hydroxypropyl methylcellulose ether, 13g putty-specific adhesive powder, and 0.2g magnesium oxide, and stir for 15 minutes to obtain pre-mixed material B.

[0053] S3. Add 4g corn starch, 2g sodium stearate, and 2g sodium hexametaphosphate to 20g water and stir at 500 rpm for 15 minutes at 60℃. Add 2g of 30μm heavy calcium carbonate and stir at 500 rpm for 20 minutes. Cool to room temperature. Add 2g water glass (modulus 2), 2g sodium tetraborate, and 2g sodium carbonate (30μm particle size, 50m² specific surface area). 2 / g of nano-antimony trioxide was mixed and stirred at 1450r / min for 30min. The mixture was then heated under reflux at 75℃ for 2h. After cooling to 40℃, the pH was adjusted to 8, and the mixture was stirred until homogeneous. The mixture was then allowed to stand for aging. After aging, 35g of isopropanol was used as a solvent for solvent replacement for 6h, followed by 25g of n-hexane as a solvent for solvent replacement for 5h. The mixture was then dried at 60℃ under normal pressure to constant weight and added to pre-mixed material B. The mixture was stirred to obtain flame-retardant and environmentally friendly interior wall putty.

[0054] Comparative Example 1

[0055] A flame-retardant and environmentally friendly interior wall putty and its preparation method include the following steps:

[0056] S1. Mix 15g of oxidized starch with a carboxyl content of 0.25% and 75g of water for 15 minutes at 90℃. Add 2g of glycerol and continue stirring for 15 minutes. Add 2g of acetic acid (10% by mass), 2g of chitosan, 6g of terminal carboxyl hyperbranched polyester with a molecular weight of 2100g / mol and an acid value of 240mg KOH / g, and 2g of ethanol. Continue stirring for 15 minutes. After the solution cools to room temperature, degas under vacuum for 2 hours to obtain pre-processed material A.

[0057] S2. Under room temperature conditions, mix pre-mixed material A, 15g guar gum, 4g graphene oxide with a particle size of 20μm, 4g hydroxypropyl methylcellulose ether, 13g putty-specific adhesive powder, and 0.2g magnesium oxide, and stir for 15 minutes to obtain pre-mixed material B.

[0058] S3. Add 4g corn starch, 2g sodium stearate, and 2g sodium hexametaphosphate to 20g water and stir at 500 rpm for 15 minutes at 60℃. Add 2g of 30μm heavy calcium carbonate and stir at 500 rpm for 20 minutes. Cool to room temperature. Add 2g water glass (modulus 2), 2g sodium tetraborate, and 2g sodium carbonate (30μm particle size, 50m² specific surface area). 2 / g of nano-antimony trioxide was mixed and stirred at 1450r / min for 30min. The mixture was then heated under reflux at 75℃ for 2h. After cooling to 40℃, the pH was adjusted to 8, and the mixture was stirred until homogeneous. The mixture was then allowed to stand for aging. After aging, 35g of isopropanol was used as a solvent for solvent replacement for 6h, followed by 25g of n-hexane as a solvent for solvent replacement for 5h. The mixture was then dried at 60℃ under normal pressure to constant weight and added to pre-mixed material B. The mixture was stirred to obtain flame-retardant and environmentally friendly interior wall putty.

[0059] Comparative Example 2

[0060] A flame-retardant and environmentally friendly interior wall putty and its preparation method include the following steps:

[0061] S1. Mix 15g of oxidized starch with a carboxyl content of 0.25% and 75g of water for 15 minutes at 90℃. Add 2g of glycerol and continue stirring for 15 minutes. Add 2g of acetic acid (10% by mass), 2g of chitosan, 6g of terminal carboxyl hyperbranched polyester with a molecular weight of 2100g / mol and an acid value of 240mg KOH / g, and 2g of ethanol. Continue stirring for 15 minutes. After the solution cools to room temperature, degas under vacuum for 2 hours to obtain pre-processed material A.

[0062] S2. Under room temperature conditions, mix pre-mixed material A, 15g guar gum, 4g graphene oxide with a particle size of 20μm, 4g hydroxypropyl methylcellulose ether, 13g putty-specific adhesive powder, and 0.2g magnesium oxide, and stir for 15 minutes to obtain pre-mixed material B.

[0063] S3. Add 4g corn starch, 2g sodium stearate, and 2g sodium hexametaphosphate to 20g water and stir at 500 rpm for 15 minutes at 60℃. Add 2g of 30μm heavy calcium carbonate and stir at 500 rpm for 20 minutes. Cool to room temperature. Add 2g of water glass (modulus 2) and 2g of 30μm antimony trioxide nanoparticles with a specific surface area of ​​50m² / g and stir at [temperature missing]. Stir at 1450 r / min for 30 min, and reflux at 75℃ for 2 h. After cooling to 40℃, adjust the pH to 8, stir and mix evenly, and let stand for aging. After standing aging is completed, first use 35g isopropanol as solvent for solvent replacement for 6 h, then use 25g n-hexane as solvent for solvent replacement for 5 h. Then dry at 60℃ under normal pressure to constant weight, add to pre-mixed material B, mix and stir to obtain flame-retardant and environmentally friendly interior wall putty.

[0064] test

[0065] The flame-retardant and environmentally friendly interior wall putty prepared in Example 5 and Comparative Examples 1-2 were divided into Example 5 group and Comparative Examples 1-2 group, and the following tests were carried out respectively.

[0066] Drying time test

[0067] The test was conducted according to the finger-touch method in Method B of JG / T 298-2010: Lightly touch the surface of the interior wall putty film with your finger; if your finger feels slightly sticky, but no putty adheres to your finger, the surface is considered dry. The test results are as follows: Figure 1 As shown, the drying time of Example 5 group was the shortest, which was better than that of Comparative Examples 1-2.

[0068] Bond strength test

[0069] Prepare mortar blocks measuring 70mm × 70mm × 20mm. Before molding, sand the surface of the mortar blocks smooth to remove surface dust. Before use, place the prepared test blocks under standard conditions for 48 hours. Place a rigid plastic sheet with a size of 40mm × 40mm and a thickness of 1mm square holes on the surface of the mortar test block. Fill and smooth the internal square holes with prepared interior wall putty, ensuring the surface is free of pits and missing corners. Then remove the square holes to obtain the test board, which is then cured flat under standard conditions for 14 days. One day before the test, use two-component epoxy resin to attach the clamp to the surface of the interior wall putty. After 14 days of curing, conduct a tensile test. After assembling and fixing the clamp to the test board using an intelligent bond strength tester, measure the maximum tensile strength of the interior wall putty along the vertical direction at a uniform and slow tensile speed; this is the bond strength. The test results are as follows: Figure 2 As shown, the bonding strength of Example 5 group was the highest at different temperatures, which was better than that of Comparative Examples 1-2.

[0070] Moisture absorption and release test

[0071] According to the standard JC / T2002-2009 "Test Method for Moisture Absorption and Desorption Properties of Building Materials", the weight of a non-hygroscopic petri dish was weighed. The prepared interior wall putty was stirred evenly with a scraper and then evenly applied to the petri dish, with the application thickness consistent with the actual product. After the sample was completely dried under natural conditions, it was placed in a desiccator with a relative humidity of 43% for 48 hours of curing. The total weight of the sample was weighed and recorded. Then, the sample was transferred to a desiccator with a relative humidity of 75%, and its moisture absorption rate was measured at 6 hours, 12 hours, 18 hours, and 24 hours. The test results are as follows. Figure 3 As shown, the moisture absorption rate of Example 5 group was the lowest at different times, which was better than that of Comparative Examples 1-2.

[0072] Thermal stability performance test

[0073] The samples were placed under nitrogen atmosphere and heated from 50°C to 650°C at a rate of 10°C / min, with a flow rate of 60 mL / min. Before testing, all samples were dried at 60°C for 12 hours. Mass was recorded every 200°C to determine the heat loss rate. The test results are as follows: Figure 4 As shown, the heat loss rate of Example 5 group was the lowest at different temperatures, which was better than that of Comparative Examples 1-2.

[0074] Flame retardant performance test

[0075] The fire resistance of interior wall putty was analyzed using an FTT0242 cone calorimeter. Interior wall putty samples of a specific size, with smooth, bubble-free surfaces, were selected and fixed on the cone calorimeter testing apparatus, ensuring the sample surface was parallel to the support. The thermal radiation power used in the experiment was 35 kW / m². 2 The sample was ignited using a high-pressure pulse spark plug, and its combustion process was observed at temperatures of 20℃, 40℃, 60℃, and 80℃ to determine the degree of melting. The test results are as follows: Figure 5 As shown, the melting rate of Example 5 group was the lowest at different temperatures, which was better than that of Comparative Examples 1-2.

[0076] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A flame-retardant and environmentally friendly interior wall putty, characterized in that, The raw materials, by weight, include: 10-20 parts oxidized starch, 10-20 parts guar gum, 10-15 parts putty-specific adhesive powder, 5-7 parts carboxyl-terminated hyperbranched polyester, 1-3 parts chitosan, 3-5 parts graphene oxide, 3-5 parts hydroxypropyl methylcellulose ether, 3-5 parts starch, 1-3 parts sodium stearate, 1-3 parts sodium hexametaphosphate, 1-3 parts water glass, 1-3 parts borate, 1-3 parts nano antimony trioxide, 1-5 parts heavy calcium carbonate, 1-3 parts acetic acid aqueous solution with a weight fraction of 8-12%, 1-3 parts ethanol, 1-3 parts glycerin, and 0.1-0.3 parts preservative; The following steps are used to prepare it: S1. Stir oxidized starch and water for 10-15 minutes at a stirring temperature of 80-90℃. Add glycerol and continue stirring for 15-20 minutes. Add acetic acid aqueous solution (8-12% by mass), chitosan, carboxyl-terminated hyperbranched polyester, ethanol, and graphene oxide. Continue stirring for 10-15 minutes. After the system cools to room temperature, degas under vacuum for 2-3 hours to obtain preform A. S2. At room temperature, mix pre-mixed material A, guar gum, hydroxypropyl methylcellulose ether, putty-specific adhesive powder, and preservative for 10-15 minutes to obtain pre-mixed material B. S3. Add starch, sodium stearate, and sodium hexametaphosphate to water and stir for 10-15 minutes at a stirring temperature of 50-60℃. Add calcium carbonate and stir for 10-20 minutes. Cool to room temperature. Add water glass, borate, and nano-antimony trioxide and stir for 20-30 minutes. Reflux at 75-85℃ for 2-8 hours. Cool to 20-40℃, adjust the pH to 8-9, stir evenly, and let stand for 10-20 hours. First, use isopropanol as a solvent for solvent replacement for 5-6 hours; then use n-hexane as a solvent for solvent replacement for 5-6 hours. Dry at 50-60℃ under normal pressure to constant weight. Add pre-prepared material B and stir evenly.

2. The flame-retardant and environmentally friendly interior wall putty according to claim 1, characterized in that, The molecular weight of carboxyl-terminated hyperbranched polyester is 1800-2100 g / mol, and the acid value is 200-240 mg KOH / g.

3. The flame-retardant and environmentally friendly interior wall putty according to claim 1, characterized in that, The particle size of graphene oxide is 10-20 μm.

4. The flame-retardant and environmentally friendly interior wall putty according to claim 1, characterized in that, The preservative is either magnesium oxide or zinc oxide.

5. The flame-retardant and environmentally friendly interior wall putty according to claim 1, characterized in that, Nano-sized antimony trioxide particles have a diameter of 20-30 μm and a specific surface area of ​​40-50 m². 2 / g.

6. The flame-retardant and environmentally friendly interior wall putty according to claim 1, characterized in that, The modulus of water glass is 2-2.

5.

7. The flame-retardant and environmentally friendly interior wall putty according to claim 1, characterized in that, The borate is sodium tetraborate.

8. The flame-retardant and environmentally friendly interior wall putty according to claim 1, characterized in that, The particle size of the calcium carbonate is 30-40 μm.

9. A method for preparing flame-retardant and environmentally friendly interior wall putty as described in any one of claims 1-8, characterized in that, Includes the following steps: S1. Stir oxidized starch and water for 10-15 minutes at a stirring temperature of 80-90℃. Add glycerol and continue stirring for 15-20 minutes. Add acetic acid aqueous solution (8-12% by mass), chitosan, carboxyl-terminated hyperbranched polyester, ethanol, and graphene oxide. Continue stirring for 10-15 minutes. After the system cools to room temperature, degas under vacuum for 2-3 hours to obtain preform A. S2. At room temperature, mix pre-mixed material A, guar gum, hydroxypropyl methylcellulose ether, putty-specific adhesive powder, and preservative for 10-15 minutes to obtain pre-mixed material B. S3. Add starch, sodium stearate, and sodium hexametaphosphate to water and stir for 10-15 minutes at a stirring temperature of 50-60℃. Add calcium carbonate and stir for 10-20 minutes. Cool to room temperature. Add water glass, borate, and nano-antimony trioxide and stir for 20-30 minutes. Reflux at 75-85℃ for 2-8 hours. Cool to 20-40℃, adjust the pH to 8-9, stir evenly, and let stand for 10-20 hours. First, use isopropanol as a solvent for solvent replacement for 5-6 hours; then use n-hexane as a solvent for solvent replacement for 5-6 hours. Dry at 50-60℃ under normal pressure to constant weight. Add pre-prepared material B and stir evenly.

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