Pressure-induced polymerization super-hydrophobic light calcium-silicon insulation board and preparation method thereof

Abstract

The invention discloses a super-hydrophobic light calcium-silicon insulation board polymerized through pressure induction and a preparation method thereof. The pressure-induced polymerization super-hydrophobic light calcium-silicon insulation board disclosed by the invention is mainly prepared from the following components in parts by weight through a pressurization foaming-pressure relief foaming process and a pressure-induced polymerization reaction: 22 to 26 parts of a high-calcium component, 24 to 28 parts of a high-silicon component, 0.6 to 0.9 part of a foaming agent, 3.2 to 3.6 parts of a dispersing agent, 0.1 to 0.2 part of graphene oxide and 7.2 to 8.5 parts of a polymeric monomer, 0.3 to 0.5 part of sodium hydrogen sulfite, 0.2 to 0.4 part of cross-linking agent and 35 to 42 parts of water. According to the invention, the super-hydrophobic and ultra-light design of the calcium-silicon insulation board is realized through a pressurization foaming-pressure relief foaming process and a pressure induced polymerization method, and a new thought is provided for the calcium-silicon insulation board with low water absorption while the calcium-silicon insulation board is ultra-light in weight.

Description

Technical Field

[0001] The invention relates to the technical field of building materials, and in particular to a pressure-induced polymerized super-hydrophobic lightweight calcium silicon insulation board and a preparation method thereof. Background Art

[0002] With the proposal of my country's "dual carbon" strategy, the building materials industry, as a major CO2 emitter, is an important way to achieve my country's "dual carbon" goals. In 2020, the national building operation phase carbon emissions were 2.16 billion tons, accounting for 21.7% of the country's total carbon emissions. Therefore, promoting ultra-low / near-zero energy consumption buildings, improving my country's building energy conservation level, and reducing building operation energy consumption and carbon emissions are important measures to achieve the "dual carbon" strategy.

[0003] Insulation materials are an important material basis for achieving ultra-low / near-zero energy consumption buildings and building energy conservation. As a typical cement-based porous, lightweight insulation material, foamed concrete has received more attention due to its low density, low shrinkage, good insulation effect, low cost, easy preparation, low thermal conductivity, fire resistance and high temperature resistance. However, the high porosity and large pore size of foamed concrete make it easy for water, salt and other components inside it to be transmitted inside, resulting in deterioration of mechanical properties and reduced service life. Therefore, it is of great significance to break through the current dilemma of high water absorption of foamed concrete and provide a new preparation method for super-hydrophobic lightweight calcium silicon insulation board. Summary of the invention

[0004] In view of this, the present invention aims to provide a pressure-induced polymerized super-hydrophobic lightweight calcium-silicon insulation board to solve the problems of mechanical property degradation and reduced service life caused by the high water absorption of existing foam concrete.

[0005] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0006] A pressure-induced polymerized super-hydrophobic lightweight calcium silicon insulation board is mainly prepared from the following components by weight through a pressure foaming-pressure relief foaming process and a pressure-induced polymerization reaction: 22-26 parts of a high-calcium component, 24-28 parts of a high-silicon component, 0.6-0.9 parts of a foaming agent, 3.2-3.6 parts of a dispersant, 0.1-0.2 parts of graphene oxide, 7.2-8.5 parts of a polymerized monomer, 0.3-0.5 parts of sodium bisulfite, 0.2-0.4 parts of a cross-linking agent, and 35-42 parts of water.

[0007] Optionally, the high calcium component is one or more of silicate cement, sulphoaluminate cement and quicklime, and the CaO content thereof is ≥65%, and the median particle size is ≤8 μm.

[0008] Optionally, the high-silicon component is one or more of quartz sand, zeolite powder, and silicon powder, and its SiO2 content is ≥80%, and the median particle size is ≤5μm.

[0009] Optionally, the foaming agent is animal protein.

[0010] Optionally, the dispersant is a polycarboxylate water reducer with a solid content of 40%.

[0011] Optionally, the polymerizable monomer is one of hydroxyethyl methacrylate and isoprene.

[0012] Optionally, the cross-linking agent is one of methylenebisacrylamide and divinylbenzene.

[0013] The second object of the present invention is to provide a method for preparing the above-mentioned pressure-induced polymerized super-hydrophobic lightweight calcium silicon insulation board, the preparation method comprising the following steps:

[0014] 1) pre-dissolving the foaming agent in part of the water, and then placing it in a pressure barrel A with a pressure of 0.15-0.35 MPa and rapidly stirring it to obtain a uniform and fine prefabricated foam;

[0015] 2) adding the high calcium component, the high silicon component and the dispersant into a pressure barrel B with a pressure of 5-8 MPa, dissolving the polymerization monomer, the sodium bisulfite and the cross-linking agent in the remaining water, and then pouring them into the pressure barrel B, stirring, and performing polymerization reaction to obtain a slurry;

[0016] 3) opening the connecting valve between the pressure barrel A and the pressure barrel B, so that the slurry and the prefabricated foam are evenly mixed in the pressure barrel A to obtain a foaming slurry;

[0017] 4) Open the pressure relief valve of the pressure barrel A, cast the foaming slurry into shape, and after the formed foaming slurry is hardened, perform pressure steam curing, and then cut it into a desired shape to obtain a pressure-induced polymerized super-hydrophobic lightweight calcium silicon insulation board.

[0018] Optionally, the rapid stirring in step 1) is at a speed of 800-1000 r / min, and the stirring time is 60-90 s; the stirring in step 2) is at a speed of 200-300 r / min, and the stirring time is 120-150 s.

[0019] Optionally, the curing temperature of the pressure steam curing in step 4) is 180° C., the humidity is 100%, the pressure is 1.2 MPa, and the curing time is 8-12 h.

[0020] The bulk density of the super-hydrophobic lightweight calcium silicon insulation board obtained by the pressure-induced polymerization method of the present invention is ≤160kg / m 3, the combustion grade is Class A non-flammable, the thermal conductivity is ≤0.05W / (m·K), the volume water absorption is ≤4%, the surface contact angle is ≥150°, and the rolling angle is ≤8°.

[0021] Preparation mechanism of the present invention:

[0022] The present invention regulates the internal pore structure of the insulation material through a pressurization-decompression process, and the pressurized foam expands uniformly during the process of returning to normal pressure, ultimately achieving an ultra-lightweight design of the calcium silicon insulation board. At the same time, polymer monomers with different functions are added to the insulation material, and the pressurized environment is used to induce the polymerization reaction, so that an in-situ polymerization reaction occurs inside the material to form a hydrophobic layer, enhance its water resistance, and thus achieve a high durability design of the insulation material.

[0023] Compared with the prior art, the pressure-induced polymerized super-hydrophobic lightweight calcium silicon insulation board of the present invention has the following advantages:

[0024] 1. The present invention adopts an in-situ polymerization reaction inside the material, so that the hydrophobic layer formed by the reaction is more evenly distributed inside the material, and the overall hydrophobic ability is enhanced. In addition, the traditional in-situ polymerization reaction occurs slowly. The present invention utilizes the pressure applied in the process of achieving ultra-lightweight materials to induce the polymerization reaction to accelerate, thereby improving the efficiency of the generation of hydrophobic components.

[0025] 2. The pressure-induced polymerization super-hydrophobic lightweight calcium silicon insulation board prepared by the present invention has a bulk density of ≤160kg / m 3 , and Class A non-flammable, thermal conductivity ≤0.05W / (m·K); volume water absorption ≤4%; surface contact angle ≥150°, rolling angle ≤8°, its various performances are superior to the current commonly used thermal insulation materials. DETAILED DESCRIPTION

[0026] In order to enable those skilled in the art to better understand the technical solutions and technical effects of the present invention, several embodiments are provided below. Obviously, what is described below is only an embodiment and does not limit the protection scope of the present invention.

[0027] Table 1 shows the raw material parameters of high calcium component and high silicon component in the super hydrophobic lightweight calcium silicon insulation board by pressure induced polymerization of Examples 1 to 10 of the present invention. Table 2 shows the raw material ratios of the super hydrophobic lightweight calcium silicon insulation board by pressure induced polymerization of Examples 1 to 10 of the present invention. Table 3 shows the key parameters of the preparation process of the super hydrophobic lightweight calcium silicon insulation board by pressure induced polymerization of Examples 1 to 10 of the present invention. Moreover, in each embodiment, the foaming agent is animal protein; the dispersant is polycarboxylic acid water reducer with a solid content of 40%; the polymerization monomer is hydroxyethyl methacrylate; and the cross-linking agent is methylenebisacrylamide.

[0028] Table 1 Raw material parameters of high calcium component and high silicon component

[0029]

[0030] Table 2 Material ratio

[0031]

[0032] Table 3 Key parameters of the preparation process

[0033]

[0034] The pressure-induced polymerized super-hydrophobic lightweight calcium silicon insulation board of Examples 1 to 6 of the present invention is specifically prepared by the following method:

[0035] 1) According to the raw material ratios in Tables 2 and 3, the foaming agent was pre-dissolved in 16 parts of water, and then placed in a pressure barrel A and rapidly stirred at a stirring speed of 1000 r / min for 90 seconds, wherein the pressure in the barrel of the pressure barrel A is as shown in Table 3, and a uniform and fine prefabricated foam was obtained;

[0036] 2) According to the raw material ratios in Table 2 and Table 3, the high calcium component, the high silicon component and the dispersant are added to the pressure barrel B, wherein the pressure in the pressure barrel B is as shown in Table 3, the polymerization monomer, sodium bisulfite and the cross-linking agent are dissolved in the remaining water, and then poured into the pressure barrel B, and stirred at a stirring rate of 300 r / min for 120 s, and each monomer is rapidly polymerized under the induction of the temperature generated by the slurry reaction and the pressure applied in the barrel to obtain a slurry;

[0037] 3) Open the connecting valve between pressure barrel A and pressure barrel B. At this time, the slurry in pressure barrel B flows into pressure barrel A. After the slurry completely flows into pressure barrel A, continue stirring for 90 seconds to mix the slurry and prefabricated foam in pressure barrel A evenly to obtain a foaming slurry;

[0038] 4) Open the pressure relief valve of pressure barrel A, cast the foaming slurry into shape, and after the formed foaming slurry is hardened, steam cure it at 180° C., 100% humidity, and 1.2 MPa pressure for 12 hours, and then cut it into the required shape to obtain a pressure-induced polymerized super-hydrophobic lightweight calcium silicon insulation board.

[0039] According to the above ratio and preparation process, the pressure-induced polymerization super-hydrophobic lightweight calcium silicon insulation board of each embodiment was prepared, and then the dry density, thermal conductivity and volume water absorption of the above embodiments 1-10 were tested with reference to the standard "Test method for performance of autoclaved aerated concrete" (GB / T 11969-2020) and the standard "Determination of steady-state thermal resistance and related properties of insulation materials - guarded hot plate method" (GB / T 10294-2008). At the same time, the surface contact angle and rolling angle of the lightweight calcium silicon insulation board were tested, and the test results are shown in Table 4.

[0040] Table 4 Test results

[0041]

[0042] It can be seen from Table 4 that the bulk density of the pressure-induced polymerized super-hydrophobic lightweight calcium silicon insulation board of each embodiment of the present invention is ≤160kg / m 3 , and Class A non-flammable, thermal conductivity ≤0.05W / (m·K); volume water absorption ≤4%; surface contact angle ≥150°, rolling angle ≤8°. The present invention introduces hydrophobic polymer monomers into the raw materials, accelerates the polymerization reaction in situ under the conditions of external pressure and internal temperature during the preparation of the insulation board, forms a hydrophobic structure inside the slurry, and then realizes super-hydrophobic design. The present invention provides a solution to the problem of high water absorption caused by high porosity and large pore size of insulation materials.

[0043] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A pressure-induced polymerized super-hydrophobic lightweight calcium silicon insulation board, characterized in that: The invention is mainly prepared from the following components by weight through a pressure foaming-pressure release foaming process and a pressure-induced polymerization reaction: 22-26 parts of a high calcium component, 24-28 parts of a high silicon component, 0.6-0.9 parts of a foaming agent, 3.2-3.6 parts of a dispersant, 0.1-0.2 parts of graphene oxide, 7.2-8.5 parts of a polymerization monomer, 0.3-0.5 parts of sodium bisulfite, 0.2-0.4 parts of a cross-linking agent and 35-42 parts of water.

2. The pressure-induced polymerized super-hydrophobic lightweight calcium silicon insulation board according to claim 1, characterized in that: The high calcium component is one or more of silicate cement, sulphoaluminate cement and quicklime, and its CaO content is ≥65%, and its median particle size is ≤8 μm.

3. The pressure-induced polymerized super-hydrophobic lightweight calcium silicon insulation board according to claim 1, characterized in that: The high silicon component is one or more of quartz sand, zeolite powder and silicon powder, and its SiO2 content is ≥80%, and the median particle size is ≤5μm.

4. The pressure-induced polymerized super-hydrophobic lightweight calcium silicon insulation board according to claim 1, characterized in that: The foaming agent is animal protein.

5. The pressure-induced polymerized super-hydrophobic lightweight calcium silicon insulation board according to claim 1, characterized in that: The dispersant is a polycarboxylic acid water reducer with a solid content of 40%.

6. The pressure-induced polymerized super-hydrophobic lightweight calcium silicon insulation board according to claim 1, characterized in that: The polymerizable monomer is one of hydroxyethyl methacrylate and isoprene.

7. The pressure-induced polymerized super-hydrophobic lightweight calcium silicon insulation board according to claim 1, characterized in that: The cross-linking agent is one of methylenebisacrylamide and divinylbenzene.

8. A method for preparing the pressure-induced polymerized super-hydrophobic lightweight calcium silicon insulation board according to any one of claims 1 to 7, characterized in that: The following steps are involved: 1) pre-dissolving the foaming agent in part of the water, and then placing it in a pressure barrel A with a pressure of 0.15-0.35 MPa and rapidly stirring it to obtain a uniform and fine prefabricated foam; 2) adding the high calcium component, the high silicon component and the dispersant into a pressure barrel B with a pressure of 5-8 MPa, dissolving the polymerization monomer, the sodium bisulfite and the cross-linking agent in the remaining water, and then pouring them into the pressure barrel B, stirring, and performing polymerization reaction to obtain a slurry; 3) opening the connecting valve between the pressure barrel A and the pressure barrel B, so that the slurry and the prefabricated foam are evenly mixed in the pressure barrel A to obtain a foaming slurry; 4) Open the pressure relief valve of the pressure barrel A, cast the foaming slurry into shape, and after the formed foaming slurry is hardened, perform pressure steam curing, and then cut it into a desired shape to obtain a pressure-induced polymerized super-hydrophobic lightweight calcium silicon insulation board.

9. The method for preparing the pressure-induced polymerized super-hydrophobic lightweight calcium silicon insulation board according to claim 8, characterized in that: The rapid stirring in step 1) is at a speed of 800-1000 r / min and a stirring time of 60-90 s; the stirring in step 2) is at a speed of 200-300 r / min and a stirring time of 120-150 s.

10. The method for preparing the pressure-induced polymerized super-hydrophobic lightweight calcium silicon insulation board according to claim 8, characterized in that: The curing temperature of the autoclave curing in step 4) is 180° C., the humidity is 100%, the pressure is 1.2 MPa, and the curing time is 8-12 hours.

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