Lightweight thermal insulation mortar, preparation method and application thereof

Abstract

The application discloses light thermal insulation mortar and a preparation method and application thereof. The light thermal insulation mortar comprises the following components in parts by weight: cement 150-260 parts; modified vitrified microbead 20-50 parts; modified silica aerogel 30-60 parts; light sand 60-150 parts; redispersible emulsion powder 1-3 parts; hydroxypropyl methyl cellulose ether 1-1.5 parts; wherein the modified vitrified microbead is modified by butadiene styrene rubber emulsion and sulfur-containing silane coupling agent; and the modified silica aerogel is composed of short-cut polypropylene fiber and silica aerogel. The modified vitrified microbead and the modified silica aerogel are introduced, and other components are matched, so that the prepared mortar has lower thermal conductivity and higher compressive strength.

Description

Technical Field

[0001] This invention relates to the field of building mortar technology, and in particular to a lightweight thermal insulation mortar, its preparation method, and its application. Background Technology

[0002] Thermal insulation mortar is a building material that uses various lightweight materials as aggregates, cement as binder, and some modified additives to construct a thermal insulation layer on the building surface. It has the advantages of being green, environmentally friendly, pollution-free, easy to construct, low overall cost, high strength, and good thermal performance.

[0003] Rock wool boards and vitrified microsphere insulation mortar are commonly used inorganic insulation materials. Rock wool boards offer advantages such as good insulation, strong fire resistance, and cost-effectiveness. However, they also have drawbacks, including complex construction procedures, lifespan not matching that of the building structure, and inability to be used on irregularly shaped structures. Vitrified microsphere insulation mortar, on the other hand, boasts good workability and a wide range of applications, making it widely popular in residential building exterior wall insulation projects. However, vitrified microspheres have some limitations; for example, during mortar preparation, they are brittle and easily break, leading to a decrease in insulation performance.

[0004] Therefore, it is necessary to develop a lightweight thermal insulation mortar with better performance. Summary of the Invention

[0005] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the first aspect of the present invention proposes a lightweight thermal insulation mortar that can reduce the breakage of vitrified microspheres and improve the mechanical strength and thermal insulation performance of the lightweight thermal insulation mortar.

[0006] A second aspect of the present invention also provides a method for preparing lightweight thermal insulation mortar.

[0007] A third aspect of the present invention also provides an application of lightweight thermal insulation mortar.

[0008] A lightweight thermal insulation mortar according to a first aspect embodiment of the present invention comprises the following components in parts by weight:

[0009]

[0010] The modified vitrified microspheres are obtained by modifying styrene-butadiene rubber latex and sulfur-containing silane coupling agent.

[0011] The modified silica aerogel is composed of chopped polypropylene fibers and silica aerogel.

[0012] The lightweight thermal insulation mortar according to embodiments of the present invention has at least the following beneficial effects:

[0013] This invention introduces modified vitrified microspheres and modified silica aerogel, along with other components of this invention, to produce mortar with lower thermal conductivity and higher compressive strength.

[0014] Furthermore, the modified vitrified microspheres in this invention are obtained by modifying styrene-butadiene rubber latex and sulfur-containing silane coupling agents; a coating layer can be formed on the surface of the vitrified microspheres, and the sulfur-containing silane coupling agent can promote the vulcanization crosslinking on the surface of the vitrified microspheres, thereby improving the compressive strength of the vitrified microspheres, making them less prone to breakage, and reducing the breakage rate of the vitrified microspheres during the preparation process.

[0015] Furthermore, the modified silica aerogel is composed of chopped polypropylene fibers and silica aerogel. This invention, by introducing chopped polypropylene fibers into the interior of the silica aerogel, can improve the compressive strength of the silica aerogel and further enhance its thermal insulation effect.

[0016] Furthermore, the redispersible latex powder can promote the dispersion of modified vitrified microspheres and modified silica aerogels, improve the cohesion of the mortar, and further enhance the thermal insulation effect.

[0017] According to some embodiments of the present invention, the modified vitrified microspheres are prepared by the following method:

[0018] Vitrified microspheres, styrene-butadiene rubber latex, and sulfur-containing silane coupling agent are mixed; solid-liquid separation yields the final product.

[0019] According to some embodiments of the present invention, the mass ratio of the styrene-butadiene rubber latex, the vitrified microspheres and the sulfur-containing silane coupling agent is 1:(0.2-0.6):(0.03-0.05).

[0020] According to some embodiments of the present invention, the modified silica aerogel is prepared by the following method:

[0021] S1. Mix the silica precursor, ethanol and water evenly, then add the acid catalyst dropwise while stirring. After the precursor is fully hydrolyzed, add the alkaline catalyst dropwise while stirring to obtain silica sol.

[0022] S2. Mix and stir the silica sol and chopped polypropylene fibers, then pulverize them to obtain a wet gel;

[0023] S3. The wet gel is successively replaced with ethanol and supercritical CO2 as solvents, and then dried by supercritical drying to obtain the final product.

[0024] According to some embodiments of the present invention, the molar ratio of silica precursor:water:ethanol:acid catalyst:alkaline catalyst is 1:(1-7):(5-28):(0.001-0.005):(0.002-0.01).

[0025] According to some embodiments of the present invention, the chopped polypropylene fibers have a length of 3 to 12 mm and a diameter of 25 to 40 μm.

[0026] According to some embodiments of the present invention, the viscosity of the hydroxypropyl methylcellulose ether is 150,000 to 200,000 mPa·s. Therefore, the hydroxypropyl methylcellulose ether exhibits excellent water retention and thickening properties, and also has a certain retarding effect.

[0027] According to some embodiments of the present invention, the viscosity is determined by the national standard GB / T10247-2008.

[0028] According to some embodiments of the present invention, the cement is silicate cement with a grade of not less than 42.5.

[0029] According to some embodiments of the present invention, the mesh size of the vitrified microspheres is 30 to 50 mesh.

[0030] According to some embodiments of the present invention, the lightweight sand is lightweight and high-strength coal slag particles.

[0031] The method for preparing the lightweight thermal insulation mortar according to a second aspect embodiment of the present invention includes the following steps:

[0032] The mixture is prepared by mixing cement, modified vitrified microspheres, modified silica aerogel, lightweight sand, redispersible latex powder, hydroxypropyl methylcellulose ether, and water.

[0033] A third aspect of the present invention provides the application of the aforementioned lightweight thermal insulation mortar in lightweight thermal insulation building materials.

[0034] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Detailed Implementation

[0035] The following are specific embodiments of the present invention, and the technical solutions of the present invention will be further described in conjunction with the embodiments, but the present invention is not limited to these embodiments.

[0036] Unless otherwise specified, the reagents, methods and equipment used in this invention are all conventional reagents, methods and equipment in this technical field.

[0037] Some of the raw materials used in the embodiments of this invention are as follows:

[0038] Cement: PO42.5 silicate cement; produced by Hunan Ningxiang Southern Cement Co., Ltd.

[0039] Lightweight sand: produced by Hunan Xiaozhi Building Materials Co., Ltd.

[0040] Redispersible latex powder: produced by Shandong Mingang Ruixiang Building Materials Technology Co., Ltd.

[0041] Hydroxypropyl methylcellulose ether: viscosity of 150,000 to 200,000, produced by Hebei Shijiazhuang Ansen Chemical Co., Ltd.

[0042] Short-cut polypropylene fibers: 3-12 mm in length and 25-40 μm in diameter, produced by Hebei Shijiazhuang Ansen Chemical Co., Ltd.

[0043] Vitrified microspheres: Vitrified microspheres produced by Hebei Yixin Energy-Saving Insulation Building Materials Factory have a mesh size of 30-50 mesh.

[0044] Preparation of modified vitrified microspheres:

[0045] According to the mass ratio of styrene-butadiene rubber latex, vitrified microspheres and sulfur-containing silane coupling agent Si-69, the vitrified microspheres, styrene-butadiene rubber latex and silane coupling agent Si-69 were mixed in a ratio of 1:0.3:0.05, and then slowly stirred at 120 r / min at 75℃ for 10 h. After that, the mixture was filtered and dried at 80℃ for 6 h to obtain the final product.

[0046] Preparation of modified silica aerogel:

[0047] S1. Mix 78 mL of tetraethyl orthosilicate, 90 mL of ethanol and 25 mL of deionized water and stir until homogeneous. Then add 2 mL of 1% hydrochloric acid dropwise and stir for 1 hour. Finally, add 9 mL of 0.1 M ammonia water dropwise and stir to obtain silica sol.

[0048] S2. Mix and stir the silica sol and chopped polypropylene fibers at 200 rpm for 30 min, let stand at 50°C for 100 min, and then mechanically pulverize for 7 min to obtain a wet gel; wherein, 2 g of chopped polypropylene fibers are added to every 100 mL of silica sol.

[0049] S3. The prepared composite wet gel is successively replaced with ethanol and supercritical CO2 as solvents, and then supercritically dried to obtain the final product.

[0050] Example 1

[0051] This example provides a lightweight thermal insulation mortar, the composition and dosage of which are shown in Table 1, and the preparation method is as follows:

[0052] The mixture is prepared by mixing cement, modified vitrified microspheres, modified silica aerogel, lightweight sand, redispersible latex powder, hydroxypropyl methylcellulose ether, and water.

[0053] Examples 2-3

[0054] Examples 2 and 3 provide a series of lightweight thermal insulation mortars, which are prepared in the same way as in Example 1, and the component dosages are shown in Table 1.

[0055] Table 1 Examples 1-3 (samples)

[0056] cement 200 150 260 Modified vitrified microspheres 30 20 50 Modified silica aerogel 40 60 30 Lightweight sand 100 150 100 Redispersible latex powder 2 1 3 Hydroxypropyl methylcellulose ether 1.2 1.5 1

[0057] Comparative Example 1

[0058] This example provides a lightweight thermal insulation mortar, which is prepared in the same way as in Example 1. The amount of its components is basically the same as in Example 1. The difference is that an equal amount of vitrified microspheres are used to replace the modified vitrified microspheres.

[0059] Comparative Example 2

[0060] This example provides a lightweight thermal insulation mortar, which is prepared in the same way as in Example 1. The amount of its components is basically the same as in Example 1. The difference is that an equal amount of silica aerogel is used to replace the modified silica aerogel.

[0061] Comparative Example 3

[0062] This example provides a lightweight thermal insulation mortar, which is prepared in the same way as in Example 1. The amount of its components is basically the same as in Example 1. The difference is that Comparative Example 3 does not contain redispersible latex powder.

[0063] Performance testing

[0064] The lightweight thermal insulation mortars of Examples 1-3 and Comparative Examples 1-3 were tested as follows, and the results are shown in Table 2.

[0065] 1) Dry density: 350~800kg / m³ 3 Test method: Prepare 6 specimens of thermal insulation and sound insulation mortar with a size of 70.7mm×70.7mm×70.7mm. Divide the mass of each specimen after drying by the volume of the specimen to obtain 6 sets of density values, and then take the arithmetic mean.

[0066] 2) 28-day compressive strength: 0.2~3MPa. Test method: Refer to GB / T 20473-2006 "Building Thermal Insulation Mortar" to test the 28-day compressive strength.

[0067] 3) Thermal conductivity: ≦0.15W / mK, Test method: Refer to GB / T 10294-2008 "Determination of steady-state thermal resistance and related properties of thermal insulation materials".

[0068] Table 2 Performance test results of Examples 1-3 and Comparative Examples 1-3

[0069] Example 1 351 1.5 0.062 Example 2 334 1.3 0.059 Example 3 373 2.7 0.071 Comparative Example 1 353 0.61 0.185 Comparative Example 2 356 0.72 0.160 Comparative Example 3 358 0.84 0.145

[0070] As can be seen from the data in Table 1, the mortar provided by this invention is lightweight, has high compressive strength, and good thermal insulation effect. However, data from Comparative Examples 1 and 2 show that without modification, both compressive strength and thermal insulation effect are poor.

[0071] Based on the data from Comparative Example 3, when redispersible latex powder is lacking, even with the addition of modified vitrified microspheres and modified silica aerogel, the compressive strength and thermal conductivity are worse than in the example due to the absence of redispersible latex powder.

[0072] The present invention has been described in detail above with reference to the embodiments of the present invention. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A lightweight thermal insulation mortar, characterized in that, Includes the following components, calculated in parts by weight: 150-260 parts cement; 20-50 parts of modified vitrified microspheres; 30-60 parts of modified silica aerogel; 60-150 parts of lightweight sand; 1-3 parts of redispersible latex powder; Hydroxypropyl methylcellulose ether, 1-1.5 parts; The modified vitrified microspheres are obtained by modifying styrene-butadiene rubber latex and sulfur-containing silane coupling agent. The modified silica aerogel is composed of chopped polypropylene fibers and silica aerogel. The modified silica aerogel was prepared by the following method: S1. Mix the silica precursor, ethanol and water evenly, then add the acid catalyst dropwise while stirring. After the precursor is fully hydrolyzed, add the alkaline catalyst dropwise while stirring to obtain silica sol. S2. Mix and stir the silica sol and chopped polypropylene fibers, then pulverize them to obtain a wet gel; S3. The wet gel is successively replaced with ethanol and supercritical CO2 as solvents, and then dried by supercritical drying to obtain the final product.

2. The lightweight thermal insulation mortar according to claim 1, characterized in that, The modified vitrified microspheres were prepared by the following method: Vitrified microspheres, styrene-butadiene rubber latex, and sulfur-containing silane coupling agent are mixed; solid-liquid separation yields the final product.

3. The lightweight thermal insulation mortar according to claim 2, characterized in that, The mass ratio of the styrene-butadiene rubber latex, vitrified microspheres, and sulfur-containing silane coupling agent is 1:(0.2~0.6):(0.03~0.05).

4. The lightweight thermal insulation mortar according to claim 1, characterized in that, In step S1, the molar ratio of silica precursor: water: ethanol: acid catalyst: basic catalyst is 1: (1~7): (5~28): (0.001~0.005): (0.002~0.01).

5. The lightweight thermal insulation mortar according to claim 1, characterized in that, The chopped polypropylene fibers have a length of 3-12 mm and a diameter of 25-40 μm.

6. The lightweight thermal insulation mortar according to claim 1, characterized in that, The viscosity of the hydroxypropyl methylcellulose ether is 150,000 to 200,000 mPa·s.

7. The lightweight thermal insulation mortar according to claim 2, characterized in that, The vitrified microspheres have a mesh size of 30-50.

8. The method for preparing lightweight thermal insulation mortar according to any one of claims 1 to 7, characterized in that, Includes the following steps: The mixture is prepared by mixing cement, modified vitrified microspheres, modified silica aerogel, lightweight sand, redispersible latex powder, hydroxypropyl methylcellulose ether, and water.

9. The application of the lightweight thermal insulation mortar according to any one of claims 1 to 7 in lightweight thermal insulation building materials.

Images