A hydrophobic mesoporous thermal insulation felt and its preparation process

Abstract

The present invention relates to the technical field of thermal insulation felts, specifically a mesoporous thermal insulation felt with hydrophobicity and its preparation process. In order to enhance the thermal insulation performance of the thermal insulation felt, the present invention uses mesoporous materials mixed with hydrophobic modified resin materials to enhance the thermal insulation felt; the present invention prepares fluorosilicon modified silane, introduces fluorine element and silicon element therein, and retains the mercapto group introduced during the reaction process, enabling it to further participate in the cross-linking of the subsequent polyurethane emulsion, improving the cross-linking degree of the resin, improving its physical properties, and the fluorine element and silicon element introduced in this process can effectively improve the hydrophobicity of the material and improve the thermal insulation ability of the thermal insulation felt in a humid environment; on this basis, the present invention further introduces mesoporous materials into the hydrophobic polyurethane emulsion, and utilizes the hollow characteristics of the mesoporous materials to improve the defect of increased thermal conductivity caused by the modification of the thermal insulation felt with polyurethane emulsion.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal insulation felts, and specifically to a mesoporous thermal insulation felt with hydrophobicity and its preparation process. Background Art

[0002] With the rapid development of the national industry, the problem of energy waste in industrial production has become increasingly serious. Thermal insulation is of great help to the rational utilization of energy. It can isolate and reduce heat dissipation, thereby achieving the purpose of reducing energy consumption.

[0003] Currently, the commonly used industrial thermal insulation products are mainly traditional materials such as ceramic fiber boards, rock wool boards, and pyrophyllite bricks, which have a relatively high thermal conductivity and are brittle. Although aerogel products have extremely high heat insulation ability, they are prone to pulverization after long-term use and have a short service life. Fiber felt products have the characteristics of soft texture and long-term use, but fiber felt products also have problems of relatively high thermal conductivity and large heat loss. Summary of the Invention

[0004] The purpose of the present invention is to provide a mesoporous thermal insulation felt with hydrophobicity and its preparation process to solve the problems raised in the prior art.

[0005] To achieve the above purpose, the present invention provides the following technical solution: A preparation process of a mesoporous thermal insulation felt with hydrophobicity, comprising the following steps:

[0006] S1. Prepare a hydrophobic polyurethane emulsion;

[0007] Heat polycarbonate diol to 105 - 110 °C, dry for 1.5 - 2 h, then add fluorosilicon-modified silane thereto, stir and mix for 2 - 4 h, stop stirring, cool to room temperature, then add isophorone diisocyanate and dibutyltin dilaurate thereto, heat to 78 - 82 °C, stir and react for 0.5 - 1.5 h, then add 2,2-dimethylolpropionic acid thereto, heat to 60 - 62 °C, continue to react for 2 - 4 h, then cool to 30 - 35 °C, add triethylamine for neutralization, add deionized water, and stir at a high speed of 1200 - 2400 rpm for 15 - 30 min to obtain a hydrophobic polyurethane emulsion;

[0008] S2. Mix mesoporous silica with the hydrophobic polyurethane emulsion, and stir and mix at a high speed of 1200 - 2400 rpm for 15 - 30 min to obtain a hydrophobic mesoporous emulsion;

[0009] S3. Immerse the thermal insulation felt body in the hydrophobic mesoporous emulsion, evacuate the pressure to 500 - 1000 Pa, after impregnating for 3 - 5 min, increase the pressure to 0.5 - 0.8 MPa, continue to impregnate for 5 - 10 min, then lift out the felt body, place it at 105 - 120 °C, dry for 4 - 6 h, and obtain a hydrophobic mesoporous thermal insulation felt.

[0010] Further, in step S1, the preparation method of the fluorosilicon - modified silane is as follows:

[0011] a. After introducing nitrogen into dimethyl sulfoxide for 0.5 - 4 h, cool it to a constant temperature in an ice - water bath, add tetramethoxysilane and sodium hydroxide to it, after mixing evenly, add bis(aminopropyl)polydimethylsiloxane, heat up to 85 - 90 °C, stir and react for 4 - 12 h, then rotary evaporate to remove the excess solvent to obtain amino - terminated silane;

[0012] b. Disperse the amino - terminated silane in DMF, stir and mix evenly, then add concentrated sulfuric acid to it, continue to mix for 3 - 5 min, then drop the mixed solution into 1,3 - propanedithiol, control the temperature of the reaction system at 4 - 15 °C during the dropping process, after the dropping is completed, heat up to 78 - 85 °C, stir and react for 1.5 - 5 h, stop heating, cool to a constant temperature in an ice - water bath, add deionized water with the same volume as DMF, stir vigorously for 1 - 3 min, then let it stand for layering, remove the aqueous phase, and vacuum evaporate the remaining mixed solution to constant weight to obtain thiol - terminated silane;

[0013] c. Disperse the thiol - terminated silane in DMF again, add benzoin butyl ether and 2 - (perfluorobutyl)ethyl acrylate to it, under the protection of a nitrogen atmosphere, carry out ultraviolet irradiation reaction for 45 - 90 min, then rotary evaporate to remove the excess solvent to obtain fluorosilicon - modified silane.

[0014] Further, in step a, by weight, the mass ratio of the tetramethoxysilane, sodium hydroxide, and bis(aminopropyl)polydimethylsiloxane is 1:(0.03 - 0.05):(6.5 - 8.5).

[0015] Further, in step b, by weight, the mass ratio of the amino - terminated silane, concentrated sulfuric acid, and 1,3 - propanedithiol is 1:(0.05 - 0.08):(0.25 - 0.31).

[0016] Further, in step c, by weight, the mass ratio of the thiol - terminated silane, benzoin butyl ether, and 2 - (perfluorobutyl)ethyl acrylate is 1:(0.02 - 0.04):(0.28 - 0.36).

[0017] Further, in step S1, by weight, the hydrophobic polyurethane emulsion consists of 42 - 48 parts of polycarbonate diol, 6 - 10 parts of fluorosilicon - modified silane, 12 - 16 parts of isophorone diisocyanate, 0.2 - 1 part of dibutyltin dilaurate, 3 - 3.5 parts of 2,2 - dimethylolpropionic acid, 2 - 2.5 parts of triethylamine, and 180 - 260 parts of deionized water;

[0018] Among them, the Mn of the polycarbonate diol is 1800 - 2500.

[0019] Further, in step S2, by weight, the mass ratio of the hydrophobic polyurethane emulsion to the mesoporous silica is 1:(0.15 - 0.4).

[0020] Further, in step S3, the insulation felt body is any one of a glass fiber felt, a basalt fiber felt, and an aluminosilicate fiber felt with a thickness of 1 - 9 mm.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] Since the thermal insulation felt is a fiber - felt - type thermal insulation material, the essence of its heat preservation is to use the fiber structure to capture air and hinder the flow of air. Since the thermal conductivity of air is low, the air in the insulation felt is enclosed between the fibers to form a heat - insulating layer, thereby reducing heat conduction and convection; however, the structure formed by the fibers of the fiber - felt - type is not a closed structure, and air can still flow in it and exchange with the outside gas. Therefore, in the face of humid weather, due to the high air humidity, when the insulation felt absorbs water and gets damp, the heat transfer effect of the insulation felt will increase significantly, seriously affecting the heat - preservation ability of the insulation felt. Therefore, in this application, a mesoporous material is mixed with a hydrophobic - modified resin material to enhance the thermal insulation felt;

[0023] The present invention first uses tetramethoxysilane as a raw material, reacts it with diaminopropyl polydimethylsiloxane containing an amino group in an acidic environment to generate a four - armed terminal amino silane, and then reacts it with 1,3 - propanedithiol containing a mercapto group, and further grafts a mercapto group therein. On this basis, the terminal mercapto silane is mixed with 2 - (perfluorobutyl) ethyl acrylate containing a fluorine element, and under the action of a photoinitiator, the mercapto group reacts with the double bond, and finally a fluorosilicon - modified silane containing fluorine, silicon elements, and a mercapto group is generated. The introduction of fluorine and silicon elements can significantly improve the hydrophobicity of the resin, thereby improving the performance of the insulation felt in a humid environment, and the retention of the terminal mercapto group enables the fluorosilicon - modified silane prepared by the present invention to further participate in the cross - linking of the subsequent polyurethane emulsion, enhancing the cross - linking degree of the resin and improving its physical properties;

[0024] On this basis, the present invention further introduces mesoporous materials into the hydrophobic polyurethane emulsion. By utilizing the hollow characteristics of the mesoporous materials, the defect of increased thermal conductivity caused by the modification of the thermal insulation felt with the polyurethane emulsion is improved. Detailed implementation mode

[0025] Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the present invention.

[0026] In this application, the polycarbonate diol used has a Mn of 2000; the mesoporous silica used is XFF11 type monodisperse mesoporous silica; the thermal insulation felt body used is a glass fiber felt with a thickness of 6 mm;

[0027] Example 1. A preparation process of a hydrophobic mesoporous thermal insulation felt, comprising the following steps:

[0028] S1. Prepare a hydrophobic polyurethane emulsion;

[0029] By weight, heat 45 parts of polycarbonate diol to 105 °C, dry for 2 h, then add 6 parts of fluorosilane-modified silane thereto, stir and mix for 2 h, stop stirring, cool to room temperature, then add 14.5 parts of isophorone diisocyanate and 0.8 part of dibutyltin dilaurate thereto, heat to 78 °C, stir and react for 1 h, then add 3.2 parts of 2,2-dimethylolpropionic acid thereto, heat to 62 °C, continue to react for 4 h, then cool to 35 °C, add 2 parts of triethylamine for neutralization, then add 230 parts of deionized water, and stir at a high speed of 1600 rpm for 25 min to obtain a hydrophobic polyurethane emulsion;

[0030] Among them, the preparation method of the fluorosilane-modified silane is:

[0031] a. By weight, after introducing nitrogen into dimethyl sulfoxide for 2 h, cool it to a constant temperature in an ice-water bath, add 1 part of tetramethoxysilane and 0.04 part of phosphoric acid thereto, mix evenly, then add 6.5 parts of diaminopropyl polydimethylsiloxane thereto, heat to 85 °C, stir and react for 8 h, and then remove the excess solvent by rotary evaporation to obtain an amino-terminated silane;

[0032] b. By weight, disperse 1 part of amino-terminated silane into DMF, stir and mix evenly, then add 0.05 part of concentrated sulfuric acid thereto. After continuing to mix for 5 min, dropwise add the mixed solution into 0.25 part of 1,3-propanedithiol. During the dropping process, control the temperature of the reaction system at 4 - 8 °C. After the dropping is completed, raise the temperature to 82 °C, stir and react for 4 h, then stop heating. After cooling to a constant temperature in an ice bath, add deionized water with the same volume as DMF, stir vigorously for 3 min, then let it stand for liquid separation. After removing the aqueous phase, vacuum evaporate the remaining mixed solution to a constant weight to obtain thiol-terminated silane;

[0033] c. By weight, disperse 1 part of thiol-terminated silane into DMF again, add 0.04 part of benzoin butyl ether and 0.28 part of 2-(perfluorobutyl)ethyl acrylate thereto, protect it under a nitrogen atmosphere, and carry out ultraviolet irradiation reaction for 80 min. Then rotary evaporate to remove the excess solvent to obtain fluorosilane-modified silane;

[0034] S2. By weight, mix 0.15 part of mesoporous silica and 1 part of hydrophobic polyurethane emulsion, and stir and mix at a high speed of 1600 rpm for 25 min to obtain a hydrophobic mesoporous emulsion;

[0035] S3. Immerse the thermal insulation felt body in the hydrophobic mesoporous emulsion, pump the pressure down to 800 Pa, immerse for 3 min, then increase the pressure to 0.75 MPa and continue to immerse for 8 min. Then lift out the felt body and place it in an environment at 115 °C and dry for 4 - 6 h to obtain a mesoporous thermal insulation felt with hydrophobicity.

[0036] Example 2. A preparation process of a mesoporous thermal insulation felt with hydrophobicity, comprising the following steps:

[0037] Compared with Example 1, this example increases the addition amount of fluorosilane-modified silane in step S1;

[0038] S1. Prepare a hydrophobic polyurethane emulsion;

[0039] By weight, heat 45 parts of polycarbonate diol to 105 °C and dry for 2 h. Then add 10 parts of fluorosilane-modified silane thereto, stir and mix for 2 h, then stop stirring. After cooling to room temperature, add 14.5 parts of isophorone diisocyanate and 0.8 part of dibutyltin dilaurate thereto, heat to 78 °C, stir and react for 1 h. Then add 3.2 parts of 2,2-dimethylolpropionic acid thereto, heat to 62 °C and continue to react for 4 h. Then cool to 35 °C, add 2 parts of triethylamine for neutralization, add 230 parts of deionized water, and stir at a high speed of 1600 rpm for 25 min to obtain a hydrophobic polyurethane emulsion;

[0040] S2. Mix 0.15 parts of mesoporous silica with 1 part of hydrophobic polyurethane emulsion by weight. After high-speed stirring at a rate of 1600 rpm for 25 min, a hydrophobic mesoporous emulsion is obtained.

[0041] S3. Immerse the insulation felt body in the hydrophobic mesoporous emulsion, pump the pressure down to 800 Pa, after impregnation for 3 min, increase the pressure to 0.75 MPa, continue impregnation for 8 min, then lift out the felt body and place it in an environment of 115 °C, dry for 4 - 6 h, and a mesoporous thermal insulation felt with hydrophobicity is obtained.

[0042] Example 3. A preparation process of a mesoporous thermal insulation felt with hydrophobicity, comprising the following steps:

[0043] Compared with Example 1, the addition amount of bis(3-aminopropyl)polydimethylsiloxane in step a is increased in this example.

[0044] Among them, the preparation method of the fluorosilane-modified silane is as follows:

[0045] a. By weight, after introducing nitrogen into dimethyl sulfoxide for 2 h, cool it to a constant temperature in an ice-water bath, add 1 part of tetramethoxysilane and 0.04 part of phosphoric acid thereto, mix evenly, then add 8.5 parts of bis(3-aminopropyl)polydimethylsiloxane thereto, raise the temperature to 85 °C, stir and react for 8 h, then rotary evaporate to remove the excess solvent to obtain an amino-terminated silane.

[0046] b. By weight, disperse 1 part of the amino-terminated silane in DMF, stir and mix evenly, then add 0.05 part of concentrated sulfuric acid thereto, continue to mix for 5 min, then dropwise add the mixed solution to 0.25 part of 1,3-propanedithiol, control the temperature of the reaction system at 4 - 8 °C during the dropping process, after the dropping is completed, raise the temperature to 82 °C, stir and react for 4 h, stop heating, cool to a constant temperature in an ice-water bath, add deionized water with the same volume as DMF, stir vigorously for 3 min, then let it stand for layer separation, remove the aqueous phase, and vacuum evaporate the remaining mixed solution to constant weight to obtain a thiol-terminated silane.

[0047] c. By weight, disperse 1 part of the thiol-terminated silane in DMF again, add 0.04 part of benzoin butyl ether and 0.28 part of 2-(perfluorobutyl)ethyl acrylate thereto, under the protection of a nitrogen atmosphere, carry out ultraviolet irradiation reaction for 80 min, then rotary evaporate to remove the excess solvent to obtain the fluorosilane-modified silane.

[0048] Example 4. A preparation process of a mesoporous thermal insulation felt with hydrophobicity, comprising the following steps:

[0049] Compared with Example 3, the addition amount of 1,3-propanedithiol in step b is increased in this example.

[0050] Among them, the preparation method of the fluorosilicon-modified silane is as follows:

[0051] a. By weight, after introducing nitrogen into dimethyl sulfoxide for 2 h, it is cooled to a constant temperature in an ice-water bath. Then, 1 part of tetramethoxysilane and 0.04 part of phosphoric acid are added thereto. After mixing evenly, 8.5 parts of diaminopropyl polydimethylsiloxane are added thereto, and the temperature is raised to 85 °C. After stirring and reacting for 8 h, the excess solvent is removed by rotary evaporation to obtain an amino-terminated silane.

[0052] b. By weight, 1 part of the amino-terminated silane is dispersed in DMF. After stirring and mixing evenly, 0.05 part of concentrated sulfuric acid is added thereto. After continuing to mix for 5 min, the mixed solution is added dropwise to 0.31 part of 1,3-propanedithiol. During the dropping process, the temperature of the reaction system is controlled at 4-8 °C. After the dropping is completed, the temperature is raised to 82 °C. After stirring and reacting for 4 h, the heating is stopped. After being cooled to a constant temperature in an ice-water bath, deionized water with the same volume as DMF is added. After vigorously stirring for 3 min, it is allowed to stand for layer separation. After removing the aqueous phase, the remaining mixed solution is vacuum-evaporated to a constant weight to obtain a mercapto-terminated silane.

[0053] c. By weight, 1 part of the mercapto-terminated silane is dispersed in DMF again. 0.04 part of benzoin butyl ether and 0.28 part of 2-(perfluorobutyl)ethyl acrylate are added thereto. Under the protection of a nitrogen atmosphere, after ultraviolet irradiation reaction for 80 min, the excess solvent is removed by rotary evaporation to obtain the fluorosilicon-modified silane.

[0054] Example 5. A preparation process of a hydrophobic mesoporous thermal insulation felt, comprising the following steps:

[0055] Compared with Example 4, the addition amount of 2-(perfluorobutyl)ethyl acrylate in step c is increased in this example;

[0056] Among them, the preparation method of the fluorosilicon-modified silane is as follows:

[0057] a. By weight, after introducing nitrogen into dimethyl sulfoxide for 2 h, it is cooled to a constant temperature in an ice-water bath. Then, 1 part of tetramethoxysilane and 0.04 part of phosphoric acid are added thereto. After mixing evenly, 8.5 parts of diaminopropyl polydimethylsiloxane are added thereto, and the temperature is raised to 85 °C. After stirring and reacting for 8 h, the excess solvent is removed by rotary evaporation to obtain an amino-terminated silane.

[0058] b. By weight, disperse 1 part of amino-terminated silane into DMF, stir and mix evenly, then add 0.05 part of concentrated sulfuric acid thereto. After continuing to mix for 5 min, drop the mixed solution into 0.31 part of 1,3-propanedithiol. During the dropping process, control the temperature of the reaction system at 4 - 8 °C. After the dropping is completed, raise the temperature to 82 °C, stir and react for 4 h, then stop heating. After cooling to a constant temperature in an ice bath, add deionized water with the same volume as DMF, stir vigorously for 3 min, then let it stand for layering. After removing the aqueous phase, vacuum-evaporate the remaining mixed solution to a constant weight to obtain thiol-terminated silane;

[0059] c. By weight, disperse 1 part of thiol-terminated silane into DMF again, add 0.04 part of benzoin butyl ether and 0.36 part of 2-(perfluorobutyl)ethyl acrylate thereto, protect it under a nitrogen atmosphere, and carry out ultraviolet irradiation reaction for 80 min. Then rotary evaporate to remove the excess solvent to obtain fluorine-silicon modified silane.

[0060] Example 6. A preparation process of a hydrophobic mesoporous thermal insulation felt, comprising the following steps:

[0061] Compared with Example 1, the addition amount of mesoporous silica in step S2 is increased in this example;

[0062] S1. Prepare a hydrophobic polyurethane emulsion;

[0063] By weight, heat 45 parts of polycarbonate diol to 105 °C, dry for 2 h, then add 6 parts of fluorine-silicon modified silane thereto, stir and mix for 2 h, then stop stirring. After cooling to room temperature, add 14.5 parts of isophorone diisocyanate and 0.8 part of dibutyltin dilaurate thereto, raise the temperature to 78 °C, stir and react for 1 h, then add 3.2 parts of 2,2-dimethylolpropionic acid thereto, raise the temperature to 62 °C, continue to react for 4 h, then cool down to 35 °C, add 2 parts of triethylamine for neutralization, then add 230 parts of deionized water, and stir at a high speed of 1600 rpm for 25 min to obtain a hydrophobic polyurethane emulsion;

[0064] S2. By weight, mix 0.35 part of mesoporous silica and 1 part of hydrophobic polyurethane emulsion, and stir and mix at a high speed of 1600 rpm for 25 min to obtain a hydrophobic mesoporous emulsion;

[0065] S3. Immerse the thermal insulation felt body in the hydrophobic mesoporous emulsion, pump the pressure to 800 Pa, immerse for 3 min, then increase the pressure to 0.75 MPa, continue to immerse for 8 min, then lift out the felt body, place it in an environment of 115 °C, and dry for 4 - 6 h to obtain a hydrophobic mesoporous thermal insulation felt.

[0066] Comparative Example 1. A preparation process of a hydrophobic mesoporous thermal insulation felt, comprising the following steps:

[0067] Compared with Example 1, no fluorosilane-modified silane was added in this example;

[0068] S1. Prepare a hydrophobic polyurethane emulsion;

[0069] By weight, heat 45 parts of polycarbonate diol to 105 °C, dry for 2 h, then cool to room temperature. Add 14.5 parts of isophorone diisocyanate and 0.8 part of dibutyltin dilaurate thereto, heat to 78 °C, stir and react for 1 h, then add 3.2 parts of 2,2-dimethylolpropionic acid thereto, heat to 62 °C, continue to react for 4 h, then cool to 35 °C, add 2 parts of triethylamine for neutralization, add 230 parts of deionized water, and stir at a high speed of 1600 rpm for 25 min to obtain a hydrophobic polyurethane emulsion;

[0070] S2. By weight, mix 0.15 part of mesoporous silica with 1 part of hydrophobic polyurethane emulsion, and stir and mix at a high speed of 1600 rpm for 25 min to obtain a hydrophobic mesoporous emulsion;

[0071] S3. Immerse the insulation felt body in the hydrophobic mesoporous emulsion, evacuate the pressure to 800 Pa, immerse for 3 min, then increase the pressure to 0.75 MPa, continue to immerse for 8 min, lift out the felt body, place it in an environment of 115 °C, dry for 4 - 6 h to obtain a mesoporous thermal insulation felt with hydrophobicity.

[0072] Comparative Example 2. A preparation process of a mesoporous thermal insulation felt with hydrophobicity, comprising the following steps:

[0073] Compared with Example 1, no mesoporous silica was added in step S2 of this comparative example;

[0074] S1. Prepare a hydrophobic polyurethane emulsion;

[0075] By weight, heat 45 parts of polycarbonate diol to 105 °C, after drying for 2 h, add 6 parts of fluorosilane-modified silane thereto, stir and mix for 2 h, then stop stirring. After cooling to room temperature, add 14.5 parts of isophorone diisocyanate and 0.8 part of dibutyltin dilaurate thereto, heat to 78 °C, stir and react for 1 h, then add 3.2 parts of 2,2-dimethylolpropionic acid thereto, heat to 62 °C, continue to react for 4 h, then cool to 35 °C, add 2 parts of triethylamine for neutralization, add 230 parts of deionized water, and stir at a high speed of 1600 rpm for 25 min to obtain a hydrophobic polyurethane emulsion;

[0076] Among them, the preparation method of the fluorosilane-modified silane is:

[0077] a. By weight, after introducing nitrogen into dimethyl sulfoxide for 2 h, it was cooled to a constant temperature in an ice-water bath. 1 part of tetramethoxysilane and 0.04 part of phosphoric acid were added thereto. After mixing evenly, 6.5 parts of diaminopropyl polydimethylsiloxane were added thereto, and the temperature was raised to 85 °C. After stirring and reacting for 8 h, the excess solvent was removed by rotary evaporation to obtain an amino-terminated silane;

[0078] b. By weight, 1 part of the amino-terminated silane was dispersed in DMF. After stirring and mixing evenly, 0.05 part of concentrated sulfuric acid was added thereto. After continuing to mix for 5 min, the mixed solution was dropped into 0.25 part of 1,3-propanedithiol. During the dropping process, the temperature of the reaction system was controlled at 4 - 8 °C. After the dropping was completed, the temperature was raised to 82 °C. After stirring and reacting for 4 h, the heating was stopped. After being cooled to a constant temperature in an ice-water bath, deionized water with the same volume as DMF was added. After vigorously stirring for 3 min, it was allowed to stand for layer separation. After removing the aqueous phase, the remaining mixed solution was evaporated to a constant weight under vacuum to obtain a thiol-terminated silane;

[0079] c. By weight, 1 part of the thiol-terminated silane was dispersed in DMF again. 0.04 part of benzoin butyl ether and 0.28 part of 2-(perfluorobutyl)ethyl acrylate were added thereto. Under the protection of a nitrogen atmosphere, after ultraviolet irradiation reaction for 80 min, the excess solvent was removed by rotary evaporation to obtain a fluorosilicon-modified silane;

[0080] S2. The insulation felt body was impregnated in a hydrophobic polyurethane emulsion. The air pressure was pumped to 800 Pa. After impregnation for 3 min, the pressure was increased to 0.75 MPa. After continuing to impregnate for 8 min, the felt body was lifted out and placed in an environment of 115 °C. After drying for 4 - 6 h, a mesoporous thermal insulation felt with hydrophobicity was obtained.

[0081] Detection: The samples prepared in Examples 1 - 6 and Comparative Examples 1 - 2 were subjected to thermal conductivity detection in accordance with GB / T 10295;

[0082] The samples prepared in Examples 1 - 6 and Comparative Examples 1 - 2 were subjected to hydrophobicity rate detection in accordance with GB / T 10299 - 2011;

[0083] The samples prepared in Examples 1 - 6 and Comparative Examples 1 - 2 were subjected to compressive strength detection in accordance with GB / T 34336 - 2017. The detection results are shown in the following table;

[0084]

[0085] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A process for preparing a hydrophobic mesoporous thermal insulation felt, characterized in that: The following steps are involved: S1. preparing a hydrophobic polyurethane emulsion; The polycarbonate diol is heated to 105-110°C, dried for 1.5-2h, and then fluorosilicone-modified silane is added thereto. After stirring and mixing for 2-4h, stirring is stopped, and after cooling to room temperature, isophorol diisocyanate and dibutyltin dilaurate are added thereto. The temperature is raised to 78-82°C, and stirred for reaction for 0.5-1.5h. Then, 2,2-dimethylolpropionic acid is added thereto. The temperature is raised to 60-62°C, and the reaction is continued for 2-4h. The temperature is then lowered to 30-35°C, triethylamine is added for neutralization, and deionized water is added thereto. The mixture is stirred at a high speed of 1200-2400rpm for 15-30min to obtain a hydrophobic polyurethane emulsion. S2. The mesoporous silica was mixed with a hydrophobic polyurethane emulsion, and the mixture was stirred at a high speed of 1200-2400 rpm for 15-30 min to obtain a hydrophobic mesoporous emulsion; S3. The thermal insulation felt is immersed in the hydrophobic mesoporous emulsion, the air pressure is evacuated to 500-1000Pa, and after immersion for 3-5min, the pressure is increased to 0.5-0.8MPa, and after continuing to immerse for 5-10min, the felt is pulled out and placed in an environment of 105-120℃. After drying for 4-6h, a hydrophobic mesoporous thermal insulation felt is obtained; In step S1, the preparation method of the fluorosilicone-modified silane is: a. After nitrogen is passed into dimethyl sulfoxide for 0.5-4h, the mixture is cooled to a constant temperature in an ice-water bath, tetramethoxysilane and phosphoric acid are added thereto, mixed evenly, bis-aminopropyl polydimethylsiloxane is added thereto, the temperature is raised to 85-90°C, the reaction is stirred for 4-12h, and the excess solvent is removed by rotary evaporation to obtain amino-terminated silane; b. Disperse the terminal amino silane in DMF, stir and mix evenly, add concentrated sulfuric acid thereto, continue mixing for 3-5 minutes, and then drop the mixture into 1,3-propanedithiol. During the dropwise addition, control the temperature of the reaction system to 4-15°C. After the dropwise addition is completed, heat to 78-85°C, stir and react for 1.5-5 hours, stop heating, and cool to constant temperature in an ice-water bath. Add an equal volume of deionized water to DMF, stir vigorously for 1-3 minutes, and allow to stand for stratification. After removing the aqueous phase, evaporate the remaining mixture in vacuo to constant weight to obtain terminal mercapto silane; c. The terminal mercaptosilane was dispersed again in DMF, to which benzoin butyl ether and 2-(perfluorobutyl) ethyl acrylate were added, and the reaction was carried out under nitrogen atmosphere for 45-90 minutes under ultraviolet irradiation, and then the excess solvent was removed by rotary evaporation to obtain fluorosilicone-modified silane; In step a, the mass ratio of tetramethoxysilane, phosphoric acid and bisaminopropyl polydimethylsiloxane is 1:(0.03-0.05):(6.5-8.5) in parts by weight.

2. The process for preparing a hydrophobic mesoporous thermal insulation felt according to claim 1, characterized in that: In step b, the mass ratio of the amino-terminated silane, concentrated sulfuric acid and 1,3-propanedithiol is 1:(0.05-0.08):(0.25-0.31) in parts by weight.

3. The process for preparing a hydrophobic mesoporous thermal insulation felt according to claim 1, characterized in that: In step c, the mass ratio of the terminal mercaptosilane, benzoin butyl ether, and 2-(perfluorobutyl)ethyl acrylate is 1:(0.02-0.04):(0.28-0.36) in parts by weight.

4. The process for preparing a hydrophobic mesoporous thermal insulation felt according to claim 1, characterized in that: In step S1, the hydrophobic polyurethane emulsion is composed of 42-48 parts of polycarbonate diol, 6-10 parts of fluorosilicone-modified silane, 12-16 parts of isophorol diisocyanate, 0.2-1 parts of dibutyltin dilaurate, 3-3.5 parts of 2,2-dimethylolpropionic acid, 2-2.5 parts of triethylamine and 180-260 parts of deionized water in parts by weight; Wherein, the Mn of the polycarbonate diol is 1800-2500.

5. The process for preparing a hydrophobic mesoporous thermal insulation felt according to claim 1, characterized in that: In step S2, the mass ratio of the hydrophobic polyurethane emulsion to the mesoporous silica is 1:(0.15-0.4) in parts by weight.

6. The process for preparing a hydrophobic mesoporous thermal insulation felt according to claim 1, characterized in that: In step S3, the thermal insulation felt body is any one of glass fiber felt, basalt fiber felt, and aluminum silicate fiber felt with a thickness of 1-9 mm.

7. A hydrophobic mesoporous thermal insulation felt prepared by the preparation process according to any one of claims 1 to 6.

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