Cement-based thermal insulation material, preparation method and application thereof

Abstract

The present invention belongs to the technical field of building materials, and specifically discloses a cement-based thermal insulation material, its preparation method, and application. The present invention effectively utilizes resources such as waste tire rubber, steel slag, coal gangue, bagasse, and coconut shells, and by correspondingly modifying rubber and coconut shell fibers and rationally proportioning them with other raw materials, thereby providing a cement-based thermal insulation material with excellent mechanical properties and thermal insulation properties, and having good economic, environmental, and social benefits. The present invention also provides a preparation method for the above-mentioned cement-based thermal insulation material, which has the advantages of a simple preparation process, readily available raw materials, easy promotion and application, and stable performance of the obtained material. The present invention can be applied to the preparation of thermal insulation building walls.

Description

Technical Field

[0001] The present invention belongs to the field of building materials, and in particular relates to a cement-based thermal insulation material, a preparation method and application thereof. Background Art

[0002] Rising energy consumption and resource depletion are serious challenges facing humanity. The implementation of a series of building energy-saving policies has driven the rapid development of insulation materials in the construction industry. Cement-based materials are one of the most widely used building materials in the industry. Cement-based insulation materials, particularly cement-based insulation wall materials developed through the recycling of waste resources, are of great significance.

[0003] Tire waste, due to its non-biodegradability, poses significant environmental risks. Therefore, by comprehensively utilizing resources such as waste steel slag, coal gangue, and waste tires, and addressing the common shortcomings of cement-based materials, such as low flexural strength and poor thermal insulation, a new cement-based building insulation material and product has been developed. This meets the energy-saving requirements of building a low-carbon economy and energy-saving and emission-reduction buildings, and is of great significance to the sustainable development of my country's economy. Summary of the Invention

[0004] In response to the common shortcomings of cement-based materials in the existing technology, such as low tensile strength and poor thermal insulation effect, the present invention comprehensively utilizes waste resources such as waste tire rubber, steel slag, coal gangue, sugarcane bagasse and coconut shells to provide a cement-based thermal insulation material. While meeting specific mechanical properties and other requirements, it improves its flexural strength and thermal insulation performance, and has good economic and social benefits.

[0005] The second object of the present invention is to provide a method for preparing the above-mentioned cement-based thermal insulation material, and to provide a production solution suitable for promotion for the preparation of the cement-based thermal insulation material.

[0006] The third object of the present invention is to provide an application of the above-mentioned cement-based thermal insulation material to provide more options for the selection of thermal insulation building walls.

[0007] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are adopted:

[0008] In a first aspect, the present invention provides a cement-based thermal insulation material comprising the following components in parts by weight: 70 to 76 parts of thermal insulation and environmentally friendly cement, 19 to 22 parts of polystyrene foam particles, 3 to 6 parts of sulfuric acid-modified rubber, 1.5 to 2.5 parts of plant fiber composite, 3 to 5 parts of gypsum, and 0.18 to 0.23 parts of a water reducer;

[0009] Wherein, the thermal insulation and environmentally friendly cement contains a modified alcoholamine compound;

[0010] The modified alcoholamine compound is obtained by polymerizing an intermediate obtained by the reaction of pyromellitic anhydride and alcoholamine substances with acrylic acid and methyl allyl alcohol polyoxyethylene ether;

[0011] The plant fiber composite comprises bagasse fiber and modified coconut shell fiber.

[0012] The present invention provides a novel cement-based thermal insulation material, which is a rubber-fiber-cement composite material. The addition of a plant fiber composite and sulfuric acid-modified rubber enables more effective bonding between the plant fiber and rubber powder and cement, significantly improving the adhesion between the plant fiber and cement, and between the rubber and cement. Compared with cement-based composite materials without sulfuric acid-modified rubber, the water absorption rate and thermal conductivity of the cement-based thermal insulation material provided by the present invention are significantly reduced. Compared with cement-based composite materials without modified coconut shell fiber, the water absorption of the cement-based thermal insulation material provided by the present invention is significantly reduced, which has a positive impact on improving the mechanical properties and durability of the material.

[0013] The modified alcoholamine compound used as a grinding aid is prepared by polymerizing an intermediate obtained by the reaction of pyromellitic anhydride and an alcoholamine substance with acrylic acid and methyl allyl alcohol polyoxyethylene ether under the action of an initiator benzoyl peroxide. The modified alcoholamine compound has a highly polar functional group and can be adsorbed on the surface of cement particles to form an adsorption film, thereby shielding the attraction between particles and preventing fine particles from reaggregating. At the same time, it can also promote the formation and expansion of particle cracks, increase the fluidity of cement raw material particles, and make the opportunities for particles to be ground more equal, thereby helping to improve grinding efficiency, optimize particle size distribution, and improve particle dispersibility.

[0014] According to statistics, around 1 billion tires reach the end of their service life each year worldwide, generating approximately 4 billion tons of tire waste. Since tires are non-biodegradable, most are disposed of in landfills, which not only pollutes the environment but also spreads disease by providing breeding grounds for pests and insects. Although there are reports that waste tires can be used as aggregate substitutes in cement-based composites, the hydrophobic nature of waste tire rubber results in poor adhesion to the remaining cement bodies, significantly reducing the strength of cement-based composites. The present invention, by modifying waste tire rubber particles with sulfuric acid at an appropriate concentration, can make the rubber surface rougher, improve the interfacial bonding between the rubber and cement slurry, and thus enhance the bonding performance with the cement matrix. Preliminary experiments have shown that sulfuric acid-modified rubber exhibits better overall performance than potassium permanganate-modified rubber when applied to cement-based materials.

[0015] As a first limitation of the above-mentioned cement-based thermal insulation material, the thermal insulation and environmentally friendly cement also includes limestone, steel slag, diatomaceous earth, vermiculite, gypsum and coal gangue.

[0016] As a further limitation of the first limitation of the above-mentioned cement-based thermal insulation material, the thermal insulation and environmentally friendly cement includes the following components in parts by weight: 70 to 80 parts of limestone, 3 to 6 parts of steel slag, 1 to 3 parts of diatomaceous earth, 2 to 4 parts of vermiculite, 0.8 to 1.6 parts of gypsum, 6 to 10 parts of coal gangue and 0.4 to 0.6 parts of modified alcoholamine compound.

[0017] Steel slag is an industrial waste discharged during the steelmaking process, and its amount is about 8% to 12% of steel production. Since a large amount of steel slag is not treated in time, it has brought a heavy burden to mankind, such as occupying a large amount of land, polluting the air and water sources, etc. Therefore, it is necessary to conduct research on the reduction, resource utilization and high-value comprehensive utilization of steel slag, so as to turn waste into treasure, thereby achieving the purpose of making full use of steel slag and reducing the pollution of the steel industry to the environment. Coal gangue is an industrial waste slag with a wide range of sources and a relatively low price, and its comprehensive utilization rate needs to be further improved. The present invention, through reasonable compounding, turns waste into treasure, and provides an effective way to comprehensively utilize industrial waste slag such as steel slag and coal gangue, with good economic benefits, environmental benefits and social benefits.

[0018] As another limitation of the first limitation of the above-mentioned cement-based thermal insulation material, the preparation method of the thermal insulation and environmentally friendly cement comprises the following steps:

[0019] S1. The limestone and vermiculite were crushed to obtain the corresponding granular material having a particle size of not more than 2cm; mixed according to the ratio to obtain a granular material mixture;

[0020] S2: coarsely grinding the granular material mixture, adding the steel slag, diatomaceous earth and the first portion of the modified alcoholamine compound, and grinding to obtain cement raw material;

[0021] S3. The raw cement material is dried and fired at a firing temperature of 1300 ℃ ~ 1400 ℃, a firing time of 35min ~ 45min, cooled, rolled, broken up, and the remaining portion of the modified alcoholamine compound is added and ground to obtain cement clinker;

[0022] S4. Mixing the cement clinker with gypsum and coal gangue to obtain thermal insulation and environmentally friendly cement.

[0023] Preferably, in step S2, the weight of the first portion of modified alcoholamine compounds accounts for 60% to 70% of the total weight of the modified alcoholamine compounds.

[0024] The preparation method of the thermal insulation and environmentally friendly cement provided by the present invention adds a grinding aid-modified alcoholamine compound in two steps to the conventional cement preparation method, which is beneficial to improving the stability of cement raw materials and cement clinker out of the mill. In addition, the raw materials used are low-priced and easily available, providing a feasible solution for the comprehensive utilization and resource utilization of steel slag and coal gangue.

[0025] As a second limitation of the above-mentioned cement-based thermal insulation material, the preparation method of the sulfuric acid-modified rubber includes: soaking waste tire particles in 8wt%~10wt% sulfuric acid for 2h~3h to obtain the waste tire particles; the diameter of the waste tire particles used is 2mm~4mm.

[0026] As a third limitation of the above-mentioned cement-based thermal insulation material, the modified coconut shell fiber is obtained by modifying coconut shell fiber with stearic acid. The specific preparation method comprises: adding 300 parts of water and 8 parts to 12 parts of stearic acid to 100 parts of coconut shell fiber with a length of 1 mm to 4 mm, and soaking the mixture in a water bath at 60° C. to 65° C. for 4 h to 6 h to obtain the modified coconut shell fiber.

[0027] Natural fiber can absorb moisture from the system and can affect cement hydration and effective performance thereof. In the present invention, use stearic acid, a saturated organic acid, as the surface modifier of plant fiber, which can interact with the hydroxyl in the coconut fiber, help it adhere and expose the hydrophobic part, improve its hydrophobic property. Coconut fiber has better fiber-matrix interface adhesion after stearic acid treatment. After adding modified coconut fiber, cement-based thermal insulation material can be made to have better strength and toughness.

[0028] As a fourth limitation of the above-mentioned cement-based thermal insulation material, the weight ratio of the bagasse fiber to the modified coconut shell fiber is 1:2-4.

[0029] In a second aspect, the present invention also provides a method for preparing the above-mentioned cement-based thermal insulation material, which comprises mixing the thermal insulation and environmentally friendly cement, polystyrene foam particles, sulfuric acid-modified rubber, plant fiber composite, gypsum and water reducer to obtain the cement-based thermal insulation material.

[0030] The preparation method of the cement-based thermal insulation material provided by the present invention has the advantages of simple preparation process, readily available raw materials, easy promotion and application, and stable performance of the obtained material.

[0031] In a third aspect, the present invention also provides the use of the above-mentioned cement-based thermal insulation material in thermal insulation walls.

[0032] Since the cement-based thermal insulation material provided by the present invention has excellent thermal insulation performance, it can be widely used in the field of thermal insulation building walls. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0034] The steel slag used in the present invention complies with GB / T 20491-2017.

[0035] Example 1

[0036] This embodiment provides a cement-based thermal insulation material, which includes the following components in parts by weight: 70 parts of environmentally friendly cement, 19 parts of polystyrene foam particles, 3 parts of sulfuric acid-modified rubber, 2.5 parts of plant fiber composite, 3 parts of gypsum, and 0.18 parts of sodium lignin sulfonate;

[0037] The thermal insulation and environmentally friendly cement comprises the following components in parts by weight: 75 parts of limestone, 4 parts of steel slag, 2 parts of diatomaceous earth, 3 parts of vermiculite, 1 part of gypsum, 8 parts of coal gangue and 0.5 parts of modified alcoholamine compound;

[0038] The plant fiber composite is prepared by compounding bagasse fiber and modified coconut shell fiber in a weight ratio of 1:3.

[0039] The preparation methods of the above-mentioned raw materials are as follows.

[0040] (1) The preparation method of the modified alcoholamine compound comprises the following steps:

[0041] Step 1: Add pyromellitic anhydride and triethanolamine in a molar ratio of 1:3 to a container, add an appropriate amount of toluenesulfonic acid, mix well, and react at 120° C. for 4.5 hours to obtain an intermediate for later use;

[0042] Step 2: The intermediate, pyromellitic anhydride, methyl allyl alcohol polyoxyethylene ether and acrylic acid are sequentially added into the reactor in a mass ratio of 5:1:3.5:3.5, and then an appropriate amount of 2,4-diphenyl-4-methyl-1-pentene and benzoyl peroxide are added dropwise at 80°C, and 2,4-diphenyl-4-methyl-1-pentene and ammonium persulfate are controlled to account for 0.5% and 2.1% of the mass of methyl allyl alcohol polyoxyethylene ether, respectively. After the addition is completed, the reaction is carried out at 65°C for 4.5 hours. After the reaction is completed, the pH value is adjusted to 7 with 30% sodium hydroxide to obtain the modified alcoholamine compound.

[0043] (2) The preparation method of the thermal insulation and environmentally friendly cement comprises the following steps:

[0044] S1. The limestone and vermiculite were crushed to obtain the corresponding granular material having a particle size of not more than 2cm; mixed according to the ratio to obtain a granular material mixture;

[0045] S2. The granular material mixture was crushed to a particle size of 30 to 80 mm using a jaw crusher, and the steel slag, diatomaceous earth and a total amount of 60% of the modified alcoholamine compound were added and mixed uniformly, ground with a ball mill, and the residue was not more than 10% through a 40 μm square hole sieve to obtain cement raw material;

[0046] S3. The raw cement material is dried and fired at a firing temperature of 1300 ℃ and a firing time of 45min. The mixture is rapidly cooled in a grate cooler, followed by roller pressing, breaking up, and then grinding the remaining portion of the modified alcoholamine compound to obtain cement clinker.

[0047] S4. Mixing the cement clinker with gypsum and coal gangue to obtain thermal insulation and environmentally friendly cement.

[0048] (3) The preparation method of the bagasse fiber comprises the following steps:

[0049] The sugarcane bagasse was chopped and the sugarcane bagasse fibers with a length of 2 mm to 4 mm and a diameter not greater than 0.2 mm were selected and dried in an oven at 105°C for 4 h.

[0050] (4) The preparation method of the modified coconut shell fiber comprises the following steps:

[0051] Add 300 parts of water and 10 parts of stearic acid to 100 parts of coconut shell fiber with a length of 1 mm to 4 mm, soak in a 65°C water bath for 4 hours, wash, and dry under reduced pressure at 80°C for 2 hours to obtain modified coconut shell fiber;

[0052] (5) The preparation method of the sulfuric acid modified rubber comprises the following steps: taking waste tire particles with a diameter of 2 mm to 4 mm and no impurities on the surface, soaking them in an 8% sulfuric acid solution with a weight of 3 times that of the waste tire particles for 2 hours to modify their surface, and drying them to obtain the sulfuric acid modified rubber.

[0053] This embodiment also provides a method for preparing the above-mentioned cement-based thermal insulation material, which comprises the following steps: uniformly mixing the above-mentioned thermal insulation and environmentally friendly cement, polystyrene foam particles, sulfuric acid-modified rubber, bagasse fiber, modified coconut shell fiber, gypsum and water reducer to obtain a cement-based thermal insulation material, which is recorded as cement-based thermal insulation material I.

[0054] Example 2

[0055] This embodiment provides a cement-based thermal insulation material, which includes the following components in parts by weight: 76 parts of environmentally friendly cement, 22 parts of polystyrene foam particles, 6 parts of sulfuric acid-modified rubber, 2 parts of plant fiber composite, 5 parts of gypsum, and 0.23 parts of sodium lignin sulfonate;

[0056] The thermal insulation and environmentally friendly cement comprises the following components in parts by weight: 70 parts of limestone, 6 parts of steel slag, 3 parts of diatomaceous earth, 2 parts of vermiculite, 0.8 parts of gypsum, 6 parts of coal gangue and 0.4 parts of modified alcoholamine compound;

[0057] The plant fiber composite is prepared by compounding bagasse fiber and modified coconut shell fiber in a weight ratio of 1:2.

[0058] The preparation methods of the above-mentioned raw materials are as follows.

[0059] (1) The preparation method of the modified alcoholamine compound comprises the following steps:

[0060] Step 1: add pyromellitic anhydride and triethanolamine in a molar ratio of 1:3.5 into a container, add an appropriate amount of toluenesulfonic acid, mix well, and react at 115° C. for 5 hours to obtain an intermediate for later use;

[0061] Step 2: The intermediate, pyromellitic anhydride, methyl allyl alcohol polyoxyethylene ether and acrylic acid are added to the reactor in a mass ratio of 5:1:4:4, and then an appropriate amount of 2,4-diphenyl-4-methyl-1-pentene and benzoyl peroxide are added dropwise at 80°C, and 2,4-diphenyl-4-methyl-1-pentene and ammonium persulfate are controlled to account for 0.5% and 2.0% of the mass of methyl allyl alcohol polyoxyethylene ether, respectively. After the addition is completed, the reaction is carried out at 62°C for 5 hours. After the reaction is completed, the pH value is adjusted to 7 with 30% sodium hydroxide to obtain the modified alcoholamine compound.

[0062] (2) The preparation method of the thermal insulation and environmentally friendly cement comprises the following steps:

[0063] S1. The limestone and vermiculite were crushed to obtain the corresponding granular material having a particle size of not more than 2cm; mixed according to the ratio to obtain a granular material mixture;

[0064] S2. The granular material mixture was crushed to a particle size of 30 to 80 mm using a jaw crusher, and the steel slag, diatomaceous earth and a total amount of 70% of the modified alcoholamine compound were added and mixed uniformly, ground with a ball mill, and the residue was not more than 10% through a 40 μm square hole sieve to obtain cement raw material;

[0065] S3. The raw cement is dried and fired at a firing temperature of 1400°C and a firing time of 35min. The mixture is rapidly cooled in a grate cooler and then rolled and broken up. The remaining portion of the modified alcoholamine compound is ground again to obtain cement clinker.

[0066] S4. Mixing the cement clinker with gypsum and coal gangue to obtain thermal insulation and environmentally friendly cement.

[0067] (3) The preparation method of the bagasse fiber comprises the following steps:

[0068] The sugarcane bagasse was chopped and the sugarcane bagasse fibers with a length of 2 mm to 4 mm and a diameter not greater than 0.2 mm were selected and dried in an oven at 105°C for 4 h.

[0069] (4) The preparation method of the modified coconut shell fiber comprises the following steps:

[0070] Add 300 parts of water and 8 parts of stearic acid to 100 parts of coconut shell fiber with a length of 1 mm to 4 mm, soak in a 60°C water bath for 6 hours, wash, and dry under reduced pressure at 80°C for 2 hours to obtain modified coconut shell fiber;

[0071] (5) The preparation method of the sulfuric acid modified rubber comprises the following steps: taking waste tire particles with a diameter of 2 mm to 4 mm and no impurities on the surface, soaking them in a 10% sulfuric acid solution with a weight of 3 times that of the waste tire particles for 3 hours to modify their surface, and drying them to obtain the sulfuric acid modified rubber.

[0072] This embodiment also provides a preparation method of the above-mentioned cement-based thermal insulation material, which comprises the following steps: mixing the above-mentioned thermal insulation and environmentally friendly cement, polystyrene foam particles, sulfuric acid-modified rubber, bagasse fiber, modified coconut shell fiber, gypsum and water reducer to obtain a cement-based thermal insulation material, which is recorded as cement-based thermal insulation material II.

[0073] Example 3

[0074] This embodiment provides a cement-based thermal insulation material, which includes the following components in parts by weight: 74 parts of environmentally friendly cement, 21 parts of polystyrene foam particles, 5 parts of sulfuric acid-modified rubber, 1.5 parts of plant fiber composite, 4 parts of gypsum, and 0.2 parts of sodium lignin sulfonate;

[0075] The thermal insulation and environmentally friendly cement comprises the following components in parts by weight: 80 parts of limestone, 3 parts of steel slag, 1 part of diatomaceous earth, 4 parts of vermiculite, 1.6 parts of gypsum, 10 parts of coal gangue and 0.6 parts of modified alcoholamine compound;

[0076] The plant fiber composite is prepared by compounding bagasse fiber and modified coconut shell fiber in a weight ratio of 1:4.

[0077] The preparation methods of the above-mentioned raw materials are as follows.

[0078] (1) The preparation method of the modified alcoholamine compound comprises the following steps:

[0079] Step 1: Add pyromellitic anhydride and triethanolamine in a molar ratio of 1:4 to a container, add an appropriate amount of toluenesulfonic acid, mix well, and react at 120° C. for 4.5 hours to obtain an intermediate for later use;

[0080] Step 2: The intermediate, pyromellitic anhydride, methyl allyl alcohol polyoxyethylene ether and acrylic acid are sequentially added into the reactor in a mass ratio of 4:1:3.8:3.5, and then an appropriate amount of 2,4-diphenyl-4-methyl-1-pentene and benzoyl peroxide are added dropwise at 80°C, and 2,4-diphenyl-4-methyl-1-pentene and ammonium persulfate are controlled to account for 0.5% and 2.0% of the mass of methyl allyl alcohol polyoxyethylene ether, respectively. After the addition is completed, the reaction is carried out at 65°C for 4.5 hours. After the reaction is completed, the pH value is adjusted to 7 with 30% sodium hydroxide to obtain the modified alcoholamine compound.

[0081] (2) The preparation method of the thermal insulation and environmentally friendly cement comprises the following steps:

[0082] S1. The limestone and vermiculite were crushed to obtain the corresponding granular material having a particle size of not more than 2cm; mixed according to the ratio to obtain a granular material mixture;

[0083] S2. The granular material mixture was crushed to a particle size of 30 to 80 mm using a jaw crusher, and the steel slag, diatomaceous earth and a total amount of 65% of the modified alcoholamine compound were added and mixed uniformly, ground with a ball mill, and the residue was not more than 10% through a 40 μm square hole sieve to obtain cement raw material;

[0084] S3. The raw cement material is dried and fired at a firing temperature of 1350 ℃ and a firing time of 40min. The mixture is rapidly cooled in a grate cooler, followed by roller pressing, breaking up, and the remaining portion of the modified alcoholamine compound is added again and ground to obtain cement clinker.

[0085] S4. Mixing the cement clinker with gypsum and coal gangue to obtain thermal insulation and environmentally friendly cement.

[0086] (3) The preparation method of the bagasse fiber comprises the following steps:

[0087] The sugarcane bagasse was chopped and the sugarcane bagasse fibers with a length of 2 mm to 4 mm and a diameter not greater than 0.2 mm were selected and dried in an oven at 105°C for 4 h.

[0088] (4) The preparation method of the modified coconut shell fiber comprises the following steps:

[0089] Add 300 parts of water and 12 parts of stearic acid to 100 parts of coconut shell fiber with a length of 1 mm to 4 mm, soak in a 62°C water bath for 5 hours, wash, and dry under reduced pressure at 80°C for 2 hours to obtain modified coconut shell fiber;

[0090] (5) The preparation method of the sulfuric acid modified rubber comprises the following steps: taking waste tire particles with a diameter of 2 mm to 4 mm and no impurities on the surface, soaking them in a 10% sulfuric acid solution with a weight of 3 times that of the waste tire particles for 2 hours to modify their surface, and drying them to obtain the sulfuric acid modified rubber.

[0091] This embodiment also provides a method for preparing the above-mentioned cement-based thermal insulation material, which comprises the following steps: uniformly mixing the above-mentioned thermal insulation and environmentally friendly cement, polystyrene foam particles, sulfuric acid-modified rubber, bagasse fiber, modified coconut shell fiber, gypsum and water reducer to obtain a cement-based thermal insulation material, which is recorded as cement-based thermal insulation material III.

[0092] Comparative Example 1

[0093] Comparative Example 1 provides a cement-based thermal insulation material. The raw materials and preparation method of the cement-based thermal insulation material in this comparative example are basically the same as those in Example 3. The only difference is that: in terms of raw materials, sulfuric acid-modified rubber is not added, and the types and amounts of other raw materials are the same as those in Example 3. The obtained product is recorded as cement-based thermal insulation material comparative example I.

[0094] Comparative Example 2

[0095] Comparative Example 2 provides a cement-based thermal insulation material. The raw materials and preparation method of the cement-based thermal insulation material in this comparative example are basically the same as those in Example 3. The only difference is that: in terms of raw materials, "1.5 parts of plant fiber composite" is replaced by "1.5 parts of sugarcane bagasse fiber", and "sulfuric acid modified rubber" is replaced by an equal amount of "potassium permanganate modified rubber". The types and amounts of other raw materials are the same as those in Example 3. The obtained product is recorded as cement-based thermal insulation material comparison II.

[0096] The preparation method of potassium permanganate modified rubber is as follows: taking waste tire particles with a diameter of 2mm to 4mm and no impurities on the surface, adding a 5wt% potassium permanganate solution with a weight of 3 times that of the waste tire particles, soaking for 2 hours to modify the surface, and drying to obtain the potassium permanganate modified rubber.

[0097] Effect Examples

[0098] The cement-based thermal insulation materials prepared in Examples 1 to 3 and Comparative Examples 1-2 were added with water at a water-cement ratio of 0.5 to prepare slurries. The five slurries were grouted and molded, and then left to stand for 24 hours for demoulding and standard curing for 28 days to prepare test blocks. The performance of different test blocks was further measured.

[0099] The dry density of the specimens was tested according to the method recommended in JG158-2019. The compressive and flexural strength tests of cement mortar were conducted according to the national standard GB / T 17671-1999, "Test Methods for Cement Mortar Strength" (ISO method). The compressive strength test was conducted using a controlled loading rate of 2 kN / s. The load cell recorded the reading after a 3-second wait when loading ceased. The flexural strength test was conducted using hydraulic loading with a reading accuracy of 0.1 MPa. The thermal conductivity of the specimens was tested using a YG-DRL02 thermal conductivity meter. Water absorption was tested according to the method described in GB / T 11970-1997, and the compressive-shear bond strength was tested according to the method described in JC / T 547-2017. The specific test results are shown in Table 1.

[0100] Table 1

[0101]

[0102] The data in Table 1 show that compared to the test blocks containing only the plant fiber composite and no sulfuric acid-modified rubber, the test blocks containing both the plant fiber composite and sulfuric acid-modified rubber exhibited superior mechanical properties and lower thermal conductivity and water absorption resistance. Replacing the modified coconut shell fiber in the plant fiber composite with an equal amount of bagasse fiber significantly increased the water absorption of the resulting test blocks. This increased water absorption increases the risk of fiber swelling, degradation, or detachment from the cement matrix at the interface, adversely affecting the mechanical properties and durability of the composite. Furthermore, sulfuric acid-modified rubber significantly improved compressive strength and compressive-shear bond strength compared to potassium permanganate rubber.

[0103] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A cement-based thermal insulation material, characterized by: The invention comprises the following components in parts by weight: 70 to 76 parts of thermal insulation and environmentally friendly cement, 19 to 22 parts of polystyrene foam particles, 3 to 6 parts of sulfuric acid-modified rubber, 1.5 to 2.5 parts of plant fiber composite, 3 to 5 parts of gypsum and 0.18 to 0.23 parts of water reducing agent; Wherein, the thermal insulation and environmentally friendly cement contains a modified alcoholamine compound; The modified alcoholamine compound is obtained by polymerizing an intermediate obtained by the reaction of pyromellitic anhydride and alcoholamine substances with acrylic acid and methyl allyl alcohol polyoxyethylene ether; The plant fiber composite comprises bagasse fiber and modified coconut shell fiber; The preparation method of the modified coconut shell fiber comprises: adding water and stearic acid to coconut shell fiber, soaking the coconut shell fiber at 60° C. to 65° C. for 4 to 6 hours to obtain the modified coconut shell fiber; The thermal insulation and environmentally friendly cement comprises the following components in parts by weight: 70 to 80 parts of limestone, 3 to 6 parts of steel slag, 1 to 3 parts of diatomaceous earth, 2 to 4 parts of vermiculite, 0.8 to 1.6 parts of gypsum, 6 to 10 parts of coal gangue, and 0.4 to 0.6 parts of modified alcoholamine compound; The preparation method of the thermal insulation and environmentally friendly cement comprises the following steps: S1. crushing limestone and vermiculite separately to obtain corresponding granular materials with a particle size not exceeding 2 cm, and mixing them to obtain a granular material mixture; S2, coarsely grinding the granular material mixture, adding the steel slag, diatomaceous earth and the first portion of the modified alcoholamine compound, and grinding to obtain cement raw material; S3, after drying the cement raw material, firing it at 1300 ° C ~ 1400 ° C for 35 min ~ 45 min, cooling, roller pressing, breaking it up, adding the remaining part of the modified alcoholamine compound and grinding it to obtain cement clinker; S4. Mixing the cement clinker, gypsum and coal gangue to obtain thermal insulation and environmentally friendly cement.

2. The cement-based thermal insulation material according to claim 1, wherein: In step S2, the weight of the first portion of the modified alcoholamine compound accounts for 60% to 70% of the total weight of the modified alcoholamine compound.

3. The cement-based thermal insulation material according to claim 1, wherein: The preparation method of the sulfuric acid modified rubber comprises: soaking waste tire particles in 8wt% to 10wt% sulfuric acid for 2h to 3h to obtain the sulfuric acid modified rubber.

4. The cement-based thermal insulation material according to claim 1, wherein: The weight ratio of the bagasse fiber to the modified coconut shell fiber is 1:2-4.

5. The method for preparing the cement-based thermal insulation material according to any one of claims 1 to 4, wherein: The preparation method comprises: uniformly mixing the thermal insulation and environmentally friendly cement, polystyrene foam particles, sulfuric acid-modified rubber, plant fiber composite, gypsum and a water reducing agent to obtain a cement-based thermal insulation material.

6. Use of the cement-based thermal insulation material according to any one of claims 1 to 4 in thermal insulation walls.

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