Flame-retardant environment-friendly interior wall putty and preparation method thereof

Abstract

The invention relates to the field of interior wall putty, and particularly discloses flame-retardant environment-friendly interior wall putty. The adhesive is prepared from the following raw materials in parts by mass: 10 to 20 parts of oxidized starch, 10 to 20 parts of guar gum, 10 to 15 parts of special adhesive powder for putty, 5 to 7 parts of carboxyl-terminated hyperbranched polyester, 1 to 3 parts of chitosan, 3 to 5 parts of graphene oxide, 3 to 5 parts of hydroxypropyl methyl cellulose ether, 3 to 5 parts of starch, 1 to 3 parts of sodium stearate, 1 to 3 parts of sodium hexametaphosphate, 1 to 3 parts of water glass, 1 to 3 parts of borate and 1 to 3 parts of nano antimony trioxide. 1-5 parts of coarse whiting, 1-3 parts of acetic acid aqueous solution with the mass fraction of 8-12%, 1-3 parts of ethanol, 1-3 parts of glycerol and 0.1-0.3 part of preservative. The invention also discloses a preparation method of the flame-retardant environment-friendly interior wall putty. The natural material guar gum is adopted and has a synergistic effect with various materials, so that the stability and flame retardance of a system are effectively enhanced.

Description

Technical Field

[0001] The invention relates to the technical field of interior wall putties, and in particular to a flame retardant and environment-friendly interior wall putty and a preparation method thereof. Background Art

[0002] As an indispensable building decoration supporting material, interior wall putty has reduced the harm of formaldehyde to people's health in recent years, but bulging and cracking of putty layer are common at present. 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 to the construction site. The flying dust has a great impact on the construction environment and workers' health. In addition, the flammability of interior wall putty polymer also poses a great hidden danger.

[0003] Drawing on the application principle of guar gum in wall coatings, guar gum added to interior wall putty not only does not contain formaldehyde, but its cost-effectiveness and storage stability are far superior to traditional putty, and it has excellent application prospects. However, it has the disadvantages of poor bonding strength and flame retardant properties that do not meet the requirements, which limits its use. Summary of the invention

[0004] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a flame retardant and environmentally friendly interior wall putty and a preparation method thereof.

[0005] A flame retardant and environment-friendly interior wall putty, the raw materials of which include, by mass, 10-20 parts of oxidized starch, 10-20 parts of guar gum, 10-15 parts of special putty glue powder, 5-7 parts of terminal carboxyl hyperbranched polyester, 1-3 parts of chitosan, 3-5 parts of graphene oxide, 3-5 parts of hydroxypropyl methylcellulose ether, 3-5 parts of starch, 1-3 parts of sodium stearate, 1-3 parts of sodium hexametaphosphate, 1-3 parts of water glass, 1-3 parts of borate, 1-3 parts of nano antimony trioxide, 1-5 parts of heavy calcium, 1-3 parts of acetic acid aqueous solution with a mass fraction of 8-12%, 1-3 parts of ethanol, 1-3 parts of glycerol, and 0.1-0.3 parts of 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 has a particle size of 20-30 μm and a specific surface area of ​​40-50 m 2 / g.

[0009] Preferably, the preservative is any one of magnesium oxide and zinc oxide.

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

[0011] Preferably, the borate is sodium tetraborate.

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

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

[0014] S1. Stir oxidized starch and water for 10-15 min at a stirring temperature of 80-90° C., add glycerol and continue stirring for 15-20 min, add 8-12% acetic acid aqueous solution, chitosan, carboxyl-terminated hyperbranched polyester, ethanol, and graphene oxide, continue stirring for 10-15 min, cool the system to room temperature, and vacuum degas for 2-3 h to obtain preform A;

[0015] S2. At room temperature, prefabricated material A, guar gum, hydroxypropyl methylcellulose ether, special rubber powder for putty, and preservative are mixed and stirred for 10-15 minutes to obtain prefabricated material B;

[0016] S3. Add starch, sodium stearate and sodium hexametaphosphate into water and stir at a speed of 500-600 r / min, a stirring time of 10-15 min and a stirring temperature of 50-60°C. Add heavy calcium 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°C for 2-8 h. Cool to 20-40°C. Adjust the pH value to 8-9. Stir and mix evenly. Allow to stand for aging for 10-20 h. First, use isopropanol as solvent to perform solvent replacement for 5-6 h. Then, use n-hexane as solvent to perform solvent replacement for 5-6 h. Subsequently, dry at 50-60°C and normal pressure to constant weight. Add prefabricated material B and stir evenly to obtain a flame retardant and environmentally friendly interior wall putty.

[0017] Beneficial effects:

[0018] Guar gum is derived from natural plants, does not contain formaldehyde, and does not pollute the environment and human health. In the present invention, the carboxyl-terminated hyperbranched polyester carries a large number of carboxyl-terminated groups, undergoes esterification reaction with chitosan and oxidized starch, forms a highly branched three-dimensional structure, the molecular chain is not easy to entangle, and has a good combination effect with guar gum. The system presents a very high viscosity and pseudoplastic fluid properties of a non-Newtonian fluid, which can not only improve the water resistance of the interior wall putty, but also has a high bonding strength of the interior wall putty, but poor flame retardancy.

[0019] The present invention combines two-dimensional flaky graphene oxide with a highly branched three-dimensional structure. Since its molecular chain is not easily entangled, graphene oxide not only has a significant doping effect therein, but also the two-dimensional flaky structure of graphene oxide is coordinated with the three-dimensional hyperbranched structure, which can significantly improve the stability of interior wall putty, and the synergistic system has excellent flame retardancy.

[0020] The present invention adds borate, which can form agglomerates in water glass, and after aerogelation, it is combined with the graphene oxide sheet structure to effectively promote the uniform dispersion of nano antimony trioxide, which not only improves the gelling quality, but also has excellent waterproof performance. When burned, it becomes a silicate foam insulation layer with good flame retardant performance, and is safe, non-toxic and cost-effective. Among them, sodium stearate can reduce the surface energy of small heavy calcium particles, reduce the tendency of particles to agglomerate, improve the dispersion of dispersed heavy calcium in the system, and further improve the stability of interior wall putty.

[0021] The invention is not only environmentally friendly, has little odor, and saves energy, but also effectively enhances the stability of the system in practical applications, while enhancing the flame retardancy and waterproofness of the system, thereby improving the use effect of the interior wall putty and extending the service life. It does not require on-site preparation, has a simple preparation method, and is suitable for large-scale production applications. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0024] Figure 3 The figure is a comparison chart of moisture absorption rate of flame retardant and environmentally friendly interior wall putties obtained by using Example 5 and Comparative Examples 1-2.

[0025] Figure 4 This is a graph showing the heat loss ratio of the flame-retardant and environmentally friendly interior wall putties obtained using Example 5 and Comparative Examples 1-2.

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

[0027] The present invention will be further explained below in conjunction with specific embodiments.

[0028] The carboxyl-terminated hyperbranched polyester used below was purchased from Wuhan Lisheng Chemical Co., Ltd.; the graphene oxide used below was purchased from Jiangsu Xian Nano Technology Co., Ltd.; the special putty rubber powder used below was purchased from Langfang Zhen Chemical Co., Ltd.

[0029] Example 1

[0030] A flame retardant and environmentally friendly interior wall putty and a preparation method thereof, comprising the following steps:

[0031] S1. Stir 10g oxidized starch and 50g water for 15min at 90℃, add 2g glycerol and continue stirring for 15min, add 1g acetic acid with a mass fraction of 10%, 1g chitosan, 5g carboxyl-terminated hyperbranched polyester with a molecular weight of 2100g / mol and an acid value of 240mgKOH / g, 1g ethanol, and 3g graphene oxide with a particle size of 20μm, and continue stirring for 15min. After the solution is cooled to room temperature, vacuum degas for 2h to obtain preform A;

[0032] S2. At room temperature, prefabricated material A, 10 g guar gum, 3 g hydroxypropyl methylcellulose ether, 10 g putty special rubber powder, and 0.1 g magnesium oxide were mixed and stirred for 15 min to obtain prefabricated material B;

[0033] S3, add 3g starch, 1g sodium stearate, 1g sodium hexametaphosphate to 10g water and stir at a speed of 500r / min, stirring time of 15min, stirring temperature of 60℃, add 1g heavy calcium with a particle size of 30μm and stir at a speed of 500r / min, stirring time of 20min, cool to room temperature, add 1g water glass with a modulus of 2, 1g sodium tetraborate, 1g particle size of 30μm, specific surface area of ​​50m 2 / g of nano antimony trioxide, stirring speed of 1450r / min, stirring for 30min, heating under reflux at 75℃ for 2h; after cooling to 40℃, adjusting pH to 8, stirring and mixing evenly, standing for aging, after standing for aging, first use 30g of isopropanol as solvent to carry out solvent replacement for 6h; then use 20g of normal hexane as solvent to carry out solvent replacement for 5h, then dry at normal pressure to constant weight at 60℃, add to prefabricated material B, mix, and stir to obtain flame retardant and environmentally friendly interior wall putty.

[0034] Example 2

[0035] A flame retardant and environmentally friendly interior wall putty and a preparation method thereof, comprising the following steps:

[0036] S1. Stir 20g oxidized starch and 100g water for 15min at 90℃, add 3g glycerol and continue stirring for 15min, add 3g acetic acid with a mass fraction of 10%, 3g chitosan, 7g carboxyl-terminated hyperbranched polyester with a molecular weight of 2100g / mol and an acid value of 240mgKOH / g, 3g ethanol, and 5g graphene oxide with a particle size of 20μm, and continue stirring for 15min. After the solution is cooled to room temperature, vacuum degas for 2h to obtain preform A;

[0037] S2. At room temperature, prefabricated material A, 20 g guar gum, 5 g hydroxypropyl methylcellulose ether, 15 g putty special rubber powder, and 0.3 g zinc oxide were mixed and stirred for 15 min to obtain prefabricated material B;

[0038] S3, add 5g starch, 3g sodium stearate, 3g sodium hexametaphosphate into 20g water and stir at a speed of 500r / min, stirring time of 15min, stirring temperature of 60℃, add 3g heavy calcium with a particle size of 30μm and stir at a speed of 500r / min, stirring time of 20min, cool to room temperature, add 3g water glass with a modulus of 2, 3g sodium tetraborate, 3g with a particle size of 30μm and a specific surface area of ​​50m 2 / g of nano antimony trioxide, stirring speed of 1450r / min, stirring for 30min, heating under reflux at 75℃ for 2h; after cooling to 40℃, adjusting pH to 8, stirring and mixing evenly, standing for aging, after standing for aging, first use 40g of isopropanol as solvent to carry out solvent replacement for 6h; then use 30g of normal hexane as solvent to carry out solvent replacement for 5h, then dry to constant weight at normal pressure at 60℃, add to prefabricated material B, mix, and stir to obtain flame retardant and environmentally friendly interior wall putty.

[0039] Example 3

[0040] A flame retardant and environmentally friendly interior wall putty and a preparation method thereof, comprising the following steps:

[0041] S1. Stir 11g oxidized starch and 80g water for 15min at 90℃, add 1.1g glycerol and continue stirring for 15min, add 1.1g acetic acid with a mass fraction of 10%, 1.1g chitosan, 5.1g carboxyl-terminated hyperbranched polyester with a molecular weight of 2100g / mol and an acid value of 240mg KOH / g, 1.1g ethanol, and 3.1g graphene oxide with a particle size of 20μm, and continue stirring for 15min. After the solution is cooled to room temperature, vacuum degassing is performed for 2h to obtain preform A;

[0042] S2. At room temperature, prefabricated material A, 11 g guar gum, 3.1 g hydroxypropyl methylcellulose ether, 11 g putty special rubber powder, and 0.11 g magnesium oxide were mixed and stirred for 15 min to obtain prefabricated material B;

[0043] S3, add 3.1g starch, 1.1g sodium stearate, 1.1g sodium hexametaphosphate to 20g water and stir at a speed of 500r / min, stirring time of 15min, stirring temperature of 60℃, add 1.1g heavy calcium with a particle size of 30μm and stir at a speed of 500r / min, stirring time of 20min, cool to room temperature, add 1.1g water glass with a modulus of 2, 1.1g sodium tetraborate, 1.1g particle size of 30μm, specific surface area of ​​50m2 / g of nano antimony trioxide, stirring speed of 1450r / min, stirring for 30min, heating under reflux at 75℃ for 2h; after cooling to 40℃, adjusting pH to 8, stirring and mixing evenly, standing for aging, after standing for aging, first use 31g of isopropanol as solvent to carry out solvent replacement for 6h; then use 21g of normal hexane as solvent to carry out solvent replacement for 5h, then dry at normal pressure to constant weight at 60℃, add to prefabricated material B, mix, and stir to obtain flame retardant and environmentally friendly interior wall putty.

[0044] Example 4

[0045] A flame retardant and environmentally friendly interior wall putty and a preparation method thereof, comprising the following steps:

[0046] S1. Stir 19g of oxidized starch and 90g of water for 15min at 90°C, add 2.9g of glycerol and continue stirring for 15min, add 2.9g of acetic acid with a mass fraction of 10%, 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, and continue stirring for 15min. After the solution is cooled to room temperature, vacuum degassing is performed for 2h to obtain preform A;

[0047] S2. At room temperature, prefabricated material A, 19 g guar gum, 4.9 g hydroxypropyl methylcellulose ether, 14.9 g putty special rubber powder, and 0.29 g magnesium oxide were mixed and stirred for 15 min to obtain prefabricated material B;

[0048] S3, add 4.9g starch, 2.9g sodium stearate, 2.9g sodium hexametaphosphate to 29g water and stir at a speed of 500r / min, stirring time of 15min, stirring temperature of 60℃, add 2.9g heavy calcium with a particle size of 30μm and stir at a speed of 500r / min, stirring time of 20min, cool to room temperature, add 2.9g water glass with a modulus of 2, 2.9g sodium tetraborate, 2.9g with a particle size of 30μm and a specific surface area of ​​50m 2 / g of nano antimony trioxide, stirring speed of 1450r / min, stirring for 30min, heating under reflux at 75℃ for 2h; after cooling to 40℃, adjusting pH to 8, stirring and mixing evenly, standing for aging, after standing for aging, first use 39g of isopropanol as solvent to carry out solvent replacement for 6h; then use 29g of normal hexane as solvent to carry out solvent replacement for 5h, then dry to constant weight at normal pressure at 60℃, add to prefabricated material B, mix, and stir to obtain flame retardant and environmentally friendly interior wall putty.

[0049] Example 5

[0050] A flame retardant and environmentally friendly interior wall putty and a preparation method thereof, comprising the following steps:

[0051] S1. Stir 15g of oxidized starch with a carboxyl content of 0.25% and 75g of water for 15min at a stirring temperature of 90°C, add 2g of glycerol and continue stirring for 15min, add 2g of acetic acid with a mass fraction of 10%, 2g of chitosan, 6g of terminal carboxyl 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, and continue stirring for 15min. After the solution is cooled to room temperature, vacuum degassing is performed for 2h to obtain preform A;

[0052] S2. At room temperature, prefabricated material A, 15 g guar gum, 4 g hydroxypropyl methylcellulose ether, 13 g putty special rubber powder, and 0.2 g magnesium oxide were mixed and stirred for 15 min to obtain prefabricated material B;

[0053] S3, add 4g corn starch, 2g sodium stearate, 2g sodium hexametaphosphate into 20g water and stir at a speed of 500r / min, stirring time of 15min, stirring temperature of 60℃, add 2g heavy calcium with a particle size of 30μm and stir at a speed of 500r / min, stirring time of 20min, cool to room temperature, add 2g water glass with a modulus of 2, 2g sodium tetraborate, 2g with a particle size of 30μm and a specific surface area of ​​50m 2 / g of nano antimony trioxide, stirring speed of 1450r / min, stirring for 30min, heating under reflux at 75℃ for 2h; after cooling to 40℃, adjusting pH to 8, stirring and mixing evenly, standing for aging, after standing for aging, first use 35g of isopropanol as solvent, carry out solvent replacement for 6h; then use 25g of normal hexane as solvent, carry out solvent replacement for 5h, then dry at normal pressure to constant weight at 60℃, add to prefabricated material B, mix, and stir 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 a preparation method thereof, comprising the following steps:

[0056] S1. Stir 15g of oxidized starch with a carboxyl content of 0.25% and 75g of water for 15min at a stirring temperature of 90°C, add 2g of glycerol and continue stirring for 15min, add 2g of acetic acid with a mass fraction of 10%, 2g of chitosan, 6g of a carboxyl-terminated hyperbranched polyester with a molecular weight of 2100g / mol and an acid value of 240mg KOH / g, and 2g of ethanol, and continue stirring for 15min. After the solution is cooled to room temperature, vacuum degassing is performed for 2h to obtain preform A;

[0057] S2. At room temperature, prefabricated material A, 15 g guar gum, 4 g graphene oxide with a particle size of 20 μm, 4 g hydroxypropyl methylcellulose ether, 13 g putty special rubber powder, and 0.2 g magnesium oxide were mixed and stirred for 15 min to obtain prefabricated material B;

[0058] S3, add 4g corn starch, 2g sodium stearate, 2g sodium hexametaphosphate into 20g water and stir at a speed of 500r / min, stirring time of 15min, stirring temperature of 60℃, add 2g heavy calcium with a particle size of 30μm and stir at a speed of 500r / min, stirring time of 20min, cool to room temperature, add 2g water glass with a modulus of 2, 2g sodium tetraborate, 2g with a particle size of 30μm and a specific surface area of ​​50m 2 / g of nano antimony trioxide, stirring speed of 1450r / min, stirring for 30min, heating under reflux at 75℃ for 2h; after cooling to 40℃, adjusting pH to 8, stirring and mixing evenly, standing for aging, after standing for aging, first use 35g of isopropanol as solvent, carry out solvent replacement for 6h; then use 25g of normal hexane as solvent, carry out solvent replacement for 5h, then dry at normal pressure to constant weight at 60℃, add to prefabricated material B, mix, and stir 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 a preparation method thereof, comprising the following steps:

[0061] S1. Stir 15g of oxidized starch with a carboxyl content of 0.25% and 75g of water for 15min at a stirring temperature of 90°C, add 2g of glycerol and continue stirring for 15min, add 2g of acetic acid with a mass fraction of 10%, 2g of chitosan, 6g of a carboxyl-terminated hyperbranched polyester with a molecular weight of 2100g / mol and an acid value of 240mg KOH / g, and 2g of ethanol, and continue stirring for 15min. After the solution is cooled to room temperature, vacuum degassing is performed for 2h to obtain preform A;

[0062] S2. At room temperature, prefabricated material A, 15 g guar gum, 4 g graphene oxide with a particle size of 20 μm, 4 g hydroxypropyl methylcellulose ether, 13 g putty special rubber powder, and 0.2 g magnesium oxide were mixed and stirred for 15 min to obtain prefabricated material B;

[0063] S3, add 4g corn starch, 2g sodium stearate, 2g sodium hexametaphosphate into 20g water and stir at a speed of 500r / min, a stirring time of 15min, and a stirring temperature of 60°C, add 2g heavy calcium with a particle size of 30μm and mix at a speed of 500r / min and a stirring time of 20min, cool to room temperature, add 2g water glass with a modulus of 2 and 2g nano antimony trioxide with a particle size of 30μm and a specific surface area of ​​50m2 / g and mix at a stirring speed of 1450r / min, stir for 30min, heat under reflux at 75℃ for 2h; after cooling to 40℃, adjust the pH to 8, stir and mix evenly, let it stand for aging, after the aging is completed, first use 35g of isopropanol as solvent to carry out solvent replacement for 6h; then use 25g of normal hexane as solvent to carry out solvent replacement for 5h, then dry at 60℃ to constant weight, add to prefabricated 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 putties 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 performed respectively.

[0066] Drying time test

[0067] The test is carried out 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 the finger feels a little sticky, but there is no interior wall putty sticking to the finger, the surface is considered dry. Figure 1 As shown, the drying time of Example 5 is the shortest, which is better than that of Comparative Examples 1-2.

[0068] Bond strength test

[0069] Prepare mortar blocks of 70mm×70mm×20mm. Use sandpaper to smooth the surface of the mortar blocks before molding, remove surface dust, and place the treated test blocks under standard conditions for 48 hours before use. Place a hard plastic with a size of 40mm×40mm and a thickness of 1mm square holes on the surface of the mortar test block. Fill and scrape the internal square frame with the prepared interior wall putty. There should be no pits or missing corners on the surface. Then remove the square frame to form a test plate. Place it flat under standard conditions for 14 days. The day before the test, use a two-component epoxy resin to stick the fixture to the surface of the interior wall putty. After curing for 14 days, perform a tensile test. After the fixture and the test plate are assembled and fixed with an intelligent bonding strength tester, the maximum tensile strength of the interior wall putty measured at a uniform and slow tensile speed in the vertical direction is the bonding strength. The test results are as follows Figure 2 As shown, the bonding strength of Example 5 is the largest at different temperatures, which is better than that of Comparative Examples 1-2.

[0070] Moisture absorption and release test

[0071] According to the specification JC / T2002-2009 "Test Method for Moisture Absorption and Desorption Performance of Building Materials", weigh the non-hygroscopic culture dish, stir the prepared interior wall putty evenly with a scraper and apply it evenly in the culture dish. The coating thickness is consistent with the actual product. After the sample is completely dried under natural conditions, place the sample in a dryer with a relative humidity of 43% for 48 hours of curing, weigh and record the total weight of the sample, and then transfer the sample to a dryer with a relative humidity of 75% to measure its 6h, 12h, 18h and 24h moisture absorption rate. The test results are as follows: Figure 3 As shown, the moisture absorption rate of Example 5 group is the smallest at different time periods, which is better than that of Comparative Examples 1-2 groups.

[0072] Thermal stability test

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

[0074] Flame retardant performance test

[0075] The fire resistance of interior wall putty was analyzed using the FTT0242 cone calorimeter. A certain size of interior wall putty sample was selected with a flat surface and no bubbles. The sample was fixed on the cone calorimeter test device to ensure that the sample surface was parallel to the bracket. The thermal radiation power used in the experiment was 35kW / m 2 , use high-voltage pulse spark plug to ignite the sample, observe its combustion process at 20℃, 40℃, 60℃, and 80℃, and get the degree of melting. The test results are as follows Figure 5 As shown, the melting rate of Example 5 is the smallest at different temperatures, which is better than that of Comparative Examples 1-2.

[0076] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A flame retardant and environmentally friendly interior wall putty, characterized in that: The raw materials include, by mass, 10-20 parts of oxidized starch, 10-20 parts of guar gum, 10-15 parts of special glue powder for putty, 5-7 parts of terminal carboxyl hyperbranched polyester, 1-3 parts of chitosan, 3-5 parts of graphene oxide, 3-5 parts of hydroxypropyl methylcellulose ether, 3-5 parts of starch, 1-3 parts of sodium stearate, 1-3 parts of sodium hexametaphosphate, 1-3 parts of water glass, 1-3 parts of borate, 1-3 parts of nano antimony trioxide, 1-5 parts of heavy calcium, 1-3 parts of acetic acid aqueous solution with a mass fraction of 8-12%, 1-3 parts of ethanol, 1-3 parts of glycerol, and 0.1-0.3 parts of preservatives.

2. The flame retardant and environmentally friendly interior wall putty according to claim 1, characterized in that: The molecular weight of the 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: The particle size of nano antimony trioxide is 20-30μm, and the specific surface area is 40-50m 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 heavy calcium is 30-40μm.

9. A method for preparing a flame retardant and environmentally friendly interior wall putty according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. Stir oxidized starch and water for 10-15 min at a stirring temperature of 80-90° C., add glycerol and continue stirring for 15-20 min, add 8-12% acetic acid aqueous solution, chitosan, carboxyl-terminated hyperbranched polyester, ethanol, and graphene oxide, continue stirring for 10-15 min, cool the system to room temperature, and vacuum degas for 2-3 h to obtain preform A; S2. Stir prefabricated material A, guar gum, hydroxypropyl methylcellulose ether, special rubber powder for putty, and preservative at room temperature for 10-15 minutes to obtain prefabricated material B; S3. Add starch, sodium stearate and sodium hexametaphosphate into water and stir for 10-15 minutes at a stirring temperature of 50-60°C. Add heavy calcium 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°C for 2-8 hours. Cool to 20-40°C. Adjust the pH value to 8-9. Stir evenly. Allow to stand for aging for 10-20 hours. First, use isopropanol as solvent to perform solvent replacement for 5-6 hours. Then, use n-hexane as solvent to perform solvent replacement for 5-6 hours. Dry at 50-60°C under normal pressure to constant weight. Add preform B and stir evenly.

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