Aerogel heat insulation composite material and preparation method thereof

Abstract

The invention relates to an aerogel heat insulation composite material and a preparation method thereof, and relates to the field of heat insulation materials, the aerogel heat insulation composite material comprises the following components by weight: 120-140 parts of a resin matrix, 20-30 parts of an aerogel composite filler, 2-8 parts of a vulcanizing agent, and 8-15 parts of a processing aid. Compared with the prior art, the preparation method has the advantages that the ethylene propylene diene monomer, the phenolic resin and the PVDF-HFP in a proper proportion are mainly used as resin matrixes and matched with the specific aerogel composite filler, so that the ablation resistance of the material is remarkably improved, and the aerogel heat insulation composite material with low heat conductivity and ablation resistance is obtained; and structural integrity protection under long-time scouring of high-temperature fuel gas can be achieved, so that the use requirements in the fields of solid rocket engine combustion chambers and the like are met.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of thermal insulation materials, in particular to an aerogel thermal insulation composite material and a preparation method thereof. BACKGROUND

[0002] In many fields such as aerospace and energy power, the structural integrity protection under high temperature environment is crucial. For example, in the combustion chamber of a solid rocket engine, the high-temperature combustion gas generated by combustion has extremely high temperature and strong scouring effect, which puts extremely strict performance requirements on the inner wall material of the combustion chamber. The material not only needs to have extremely low thermal conductivity to effectively block heat transfer and reduce heat conduction to other parts of the engine, so as to ensure that each part inside the engine works normally at a suitable temperature; at the same time, it must have excellent ablation resistance, which can maintain the structural stability of itself under long-time high-temperature gas scouring and not be ablated and destroyed, so as to ensure the safe and reliable operation of the engine.

[0003] At present, although certain progress has been made in the field of thermal insulation materials, various types of thermal insulation materials have been developed, but the existing materials still have many shortcomings in performance, and it is difficult to simultaneously meet the dual requirements of low thermal conductivity and ablation resistance. SUMMARY

[0004] To solve the above problems, the present application provides an aerogel thermal insulation composite material and a preparation method thereof.

[0005] In a first aspect, the present application provides an aerogel thermal insulation composite material, which comprises the following components in parts by weight:

[0006] resin matrix 120-140 parts, aerogel composite filler 20-30 parts, vulcanizing agent 2-8 parts and processing aid 8-15 parts;

[0007] The resin matrix is composed of ternary ethylene-propylene rubber, phenolic resin and PVDF-HFP in a mass ratio of (95-105):(14-21):(10-15), and the molecular weight of the PVDF-HFP is 500,000-600,000.

[0008] The aerogel composite filler is obtained by treating silica aerogel and zirconium oxide with a silane coupling agent.

[0009] Further, the aerogel thermal insulation composite material comprises the following components in parts by weight:

[0010] resin matrix 130 parts, aerogel composite filler 27 parts, vulcanizing agent 5 parts and processing aid 12 parts.

[0011] Further, the resin matrix is composed of EPDM, phenolic resin and PVDF-HFP with a mass ratio of 100:17:12.

[0012] Further, the PVDF-HFP includes at least one of PVDF-HFP with a product model of PVDF-HFP 21216 and PVDF-HFP with a product model of PVDF-HFP LBG.

[0013] Further, the preparation method of the aerogel composite filler includes the following processes:

[0014] The silica aerogel with a bulk density of 25-50 kg / m 3 is subjected to a first heating treatment in an air atmosphere to obtain modified silica aerogel;

[0015] The modified silica aerogel, the first zirconia with a particle size of 12-16 μm and the second zirconia with a particle size of 1-3 μm are stirred and mixed according to a mass ratio of (9-13):(0.5-1):(2-3.5) to obtain dry mixture;

[0016] Under continuous stirring, the dry mixture is sprayed with a silane coupling agent hydroalcoholic solution with a pH of 4-5, and then subjected to a second heating treatment to obtain the aerogel composite filler.

[0017] Further, the working condition parameters of the first heating treatment include a temperature of 240-280℃ and a time of 30-60s;

[0018] And / or, the working condition parameters of the second heating treatment include a temperature of 115-125℃ and a time of 60-120min.

[0019] Further, the preparation of the silane hydroalcoholic solution includes the following processes: γ-aminopropyl triethoxysilane is added to a solvent composed of ethanol and water with a volume ratio of (3-5):1, followed by adding acetic acid to adjust the system pH to 4-5 and stirring for 20-40min to obtain the silane coupling agent hydroalcoholic solution containing 5-10% of γ-aminopropyl triethoxysilane by mass fraction;

[0020] The amount of silane coupling agent used in the spraying process accounts for 1.0-2.5% of the weight of the dry mixture.

[0021] Further, the vulcanizing agent is composed of elemental sulfur and dicumyl peroxide with a mass ratio of (1-2):(3-4), and the processing aid includes paraffin oil.

[0022] In a second aspect, based on the same inventive concept, the present application provides a preparation method of the aerogel thermal insulation composite material of any one of the first aspect, the preparation method comprising the following steps:

[0023] mixing the components in the aerogel thermal insulation composite material to obtain a mixed rubber;

[0024] after the mixed rubber is left to stand, performing vulcanization treatment to obtain the aerogel thermal insulation composite material.

[0025] Further, the working condition parameters of the mixing include that the temperature is 115-120℃.

[0026] and / or, the working condition parameters of the vulcanization treatment include that the temperature is 155-165℃ and the pressure is 10-15Mpa.

[0027] Compared with the prior art, the above technical solutions provided by the embodiments of the present application have at least the following advantages:

[0028] The embodiments of the present application provide an aerogel thermal insulation composite material and a preparation method thereof. Compared with the prior art, on the one hand, the present application uses a combination of ethylene propylene diene rubber (EPDM), phenolic resin and PVDF-HFP (polyvinylidene fluoride-hexafluoropropylene copolymer) as a resin matrix, and forms a more compact three-dimensional network structure by introducing an appropriate amount of high molecular weight PVDF-HFP, which is beneficial to improve the heat resistance and long-term structural stability of the material. On the other hand, the present application reduces the permanent compression deformation of the silica aerogel by first heating treatment, and performs composite treatment with zirconia of different gradations to form a multi-scale synergistic heat resistance-anti-ablation mechanism. Based on this, the present application realizes the dual improvement of low thermal conductivity and anti-ablation performance through the optimization of the resin matrix and the gradient heat resistance structure design of the aerogel composite filler, and obtains an aerogel thermal insulation composite material with low thermal conductivity and anti-ablation. It can realize the structural integrity protection under the long-time scouring of high-temperature gas, thereby meeting the use requirements in fields such as solid rocket engine combustion chamber. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0030] Unless otherwise specifically explained, various raw materials, reagents, instruments and equipment used in the present application can be purchased on the market or prepared by existing methods. At the same time, if there is no special limitation or specific description, the steps and parameters can be carried out according to the existing processing technology or directly using the existing equipment, and the present application document will not be described one by one.

[0031] The present application will be further described in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present application and not to limit the scope of the present application. The experimental methods in the following examples are not specified, which are generally determined according to the national standards. If there is no corresponding national standard, it is carried out according to the general international standard, the conventional condition, or according to the conditions suggested by the manufacturer.

[0032] The main raw material information involved in the following examples and comparative examples is as follows:

[0033] ‌Ethylene propylene diene rubber (commercially available): product type is Mitsui Chemical EPT EPDM 3092M.

[0034] Phenolic resin (commercially available): product type is phenolic resin 2120.

[0035] ‌PVDF-HFP 1 (commercially available): product type is Arkema PVDF-HFP 21216, molecular weight is 570,000-600,000.

[0036] ‌PVDF-HFP 2 (commercially available): product type is Arkema PVDF-HFP LBG, molecular weight is 500,000-600,000.

[0037] ‌PVDF-HFP 3 (commercially available): product type is Arkema PVDF-HFP 21510, molecular weight is 290,000-310,000.

[0038] Silica aerogel (commercially available): product type is Cabot ENOVA AEROGEL MT1100, bulk density is 25-50 kg / m 3 .

[0039] Zirconium oxide 1 (commercially available): product type is DK-3CH of DKK, particle size is 12-16 μm.

[0040] Zirconium oxide 2 (commercially available): product type is DK-2 of DKK, particle size is 1-3 μm.

[0041] Silane coupling agent hydroalcoholic solution (self-made): γ-aminopropyl triethoxysilane is added to a solvent composed of ethanol and water in a volume ratio of 4:1, followed by adding acetic acid to adjust the pH of the system to 4.8 and stirring for 30 min to obtain a silane coupling agent hydroalcoholic solution containing 8% of γ-aminopropyl triethoxysilane.

[0042] Example 1

[0043] The example provides an aerogel thermal insulation composite material, which comprises the following components in parts by weight:

[0044] a resin matrix 130 parts, an aerogel composite filler 27 parts, a vulcanizing agent 5 parts and a processing aid 12 parts;

[0045] The resin matrix is composed of ethylene-propylene-diene rubber, phenolic resin and PVDF-HFP (specifically, PVDF-HFP 1) in a mass ratio of 100:17:12;

[0046] The preparation method of the aerogel composite filler comprises the following processes: first heating treatment of silica aerogel with a bulk density of 25-50 kg / m 3 in an air atmosphere, at a temperature of 260°C for 45s to obtain modified silica aerogel; stirring and mixing the modified silica aerogel, zirconium oxide 1 and zirconium oxide 2 in a mass ratio of 10:0.7:3.0 to obtain dry mixture; under continuous stirring, spraying a silane coupling agent hydroalcoholic solution to the dry mixture, the amount of silane coupling agent used in the spraying process accounting for 2.0% of the weight of the dry mixture; then second heating treatment at a temperature of 120°C for 90min to obtain the aerogel composite filler;

[0047] The vulcanizing agent is composed of elemental sulfur and dicumyl peroxide in a mass ratio of 1:3.5;

[0048] The processing aid is paraffin oil.

[0049] The preparation method of the above aerogel thermal insulation composite material comprises the following steps:

[0050] Mixing ethylene-propylene-diene rubber using an open two-roll mixer, and adding the remaining components after the ethylene-propylene-diene rubber is wrapped on the roll to continue mixing, the mixing temperature is 118°C, and the mixing is carried out until the components are uniformly mixed to obtain a mixed rubber; placing the mixed rubber after standing for 24h into a mold, and using a flat vulcanizing machine to vulcanize the mixed rubber, the temperature is 160°C, the pressure is 12.5Mpa, and the time is 25min to obtain the aerogel thermal insulation composite material.

[0051] Example 2

[0052] The example provides an aerogel thermal insulation composite material, which comprises the following components in parts by weight:

[0053] a resin matrix 120 parts, an aerogel composite filler 20 parts, a vulcanizing agent 4 parts and a processing aid 10 parts;

[0054] The resin matrix is composed of terpolymer, phenolic resin and PVDF-HFP (specifically, PVDF-HFP 2) with a mass ratio of 95:14:10;

[0055] The preparation method of the aerogel composite filler includes the following processes: first heating treatment of silica aerogel with a bulk density of 25-50 kg / m 3 The modified silica aerogel, zirconium oxide 1 and zirconium oxide 2 are stirred and mixed according to a mass ratio of 9:0.5:2.0 to obtain dry mixture; under continuous stirring, the dry mixture is sprayed with a silane coupling agent hydroalcoholic solution, and the amount of silane coupling agent used in the spraying process accounts for 2.0% of the weight of the dry mixture; then, second heating treatment is carried out at a temperature of 120℃ for 90min to obtain the aerogel composite filler;

[0056] The vulcanizing agent is composed of elemental sulfur and dicumyl peroxide with a mass ratio of 1:3.5;

[0057] The processing aid is paraffin oil.

[0058] The preparation method of the aerogel thermal insulation composite material is the same as that of Example 1.

[0059] Example 3

[0060] This example provides an aerogel thermal insulation composite material, which includes the following components in weight parts:

[0061] Resin matrix 140 parts, aerogel composite filler 30 parts, vulcanizing agent 7 parts and processing aid 15 parts;

[0062] The resin matrix is composed of terpolymer, phenolic resin and PVDF-HFP (specifically, PVDF-HFP 1) with a mass ratio of 105:21:15;

[0063] The preparation method of the aerogel composite filler includes the following processes: first heating treatment of silica aerogel with a bulk density of 25-50 kg / m 3The silica aerogel is subjected to a first heating treatment in an air atmosphere at a temperature of 275℃ for 30s to obtain a modified silica aerogel; the modified silica aerogel, zirconium oxide 1 and zirconium oxide 2 are stirred and mixed according to a mass ratio of 9:0.5:2.0 to obtain a dry mixture; under continuous stirring, a silane coupling agent hydroalcoholic solution is sprayed onto the dry mixture, the amount of silane coupling agent used in the spraying process accounting for 2.0% of the weight of the dry mixture; then a second heating treatment is carried out at a temperature of 125℃ for 60min to obtain the aerogel composite filler;

[0064] The vulcanizing agent is composed of elemental sulfur and dicumyl peroxide in a mass ratio of 1:3.5;

[0065] The processing aid is paraffin oil.

[0066] The preparation method of the aerogel thermal insulation composite material is the same as that of Example 1.

[0067] Comparative Example 1

[0068] This example provides an aerogel thermal insulation composite material and a preparation method thereof, which is different from Example 1 only in that:

[0069] (1) The resin matrix is composed of ternary ethylene-propylene rubber, phenolic resin and PVDF-HFP (specifically, PVDF-HFP 1) in a mass ratio of 100:9:20 (i.e., the amount of PVDF-HFP added is relatively excessive).

[0070] Comparative Example 2

[0071] This example provides an aerogel thermal insulation composite material and a preparation method thereof, which is different from Example 1 only in that:

[0072] (1) PVDF-HFP 1 in Example 1 is adjusted to PVDF-HFP 3 (i.e., the molecular weight of PVDF-HFP is too small).

[0073] Comparative Example 3

[0074] This example provides an aerogel thermal insulation composite material and a preparation method thereof, which is different from Example 1 only in that:

[0075] (1) The silica aerogel in the aerogel composite filler is not subjected to a modification treatment, and a single particle size of zirconium oxide is used and subjected to silane; the specific preparation method comprises the following steps: a silica aerogel with a bulk density of 25~50 kg / m 3The silica aerogel and zirconium oxide 2 are mixed by stirring at a mass ratio of 10:3.7 to obtain dry mixture; under continuous stirring, a silane coupling agent hydroalcoholic solution is sprayed to the dry mixture, and the amount of silane coupling agent used in the spraying process accounts for 2.0% of the weight of the dry mixture; then a second heating treatment is carried out, the temperature is 120 DEG C, and the time is 90 min, to obtain the aerogel composite filler.

[0076] Test Example

[0077] In this example, the ablation resistance of the aerogel thermal insulation composite materials obtained in the above examples 1-3 and comparative examples 1-3 is investigated; wherein the test condition parameters include: propellant combustion temperature 3425K, characteristic velocity 1550m / s, and average molecular weight of combustion gas 27; the propellant is end-face combustion, the combustion surface diameter is 180mm, and the burning rate at 8MPa is 9.5mm / s. The ablation resistance is expressed by linear ablation rate (mm / s), and the smaller the linear ablation rate, the better the ablation resistance. The test results are shown in Table 1.

[0078] Table 1

[0079] Test Group Linear Ablation Rate (mm / s) Example 1 0.05 Example 2 0.10 Example 3 0.08 Comparative Example 1 0.37 Comparative Example 2 0.29 Comparative Example 3 0.52

[0080] As can be seen from Table 1, compared with comparative examples 1-3, the linear ablation rate of the aerogel thermal insulation composite material provided in the examples of the present application is significantly reduced, and the linear ablation rate is maintained at 0.10mm / s or less, indicating that it has excellent ablation resistance. At the same time, the thermal conductivity of the aerogel thermal insulation composite material obtained in examples 1-3 of the present application is further tested, and the test results show that the thermal conductivity coefficient is <0.05 W / m·K, which has low thermal conductivity characteristics.

[0081] In summary, the examples of the present application provide an aerogel thermal insulation composite material and a preparation method thereof. Compared with the prior art, the present application mainly uses ternary ethylene-propylene rubber, phenolic resin and PVDF-HFP as the resin matrix at a suitable ratio and cooperates with a specific aerogel composite filler, which significantly improves the ablation resistance of the material, and obtains an aerogel thermal insulation composite material with low thermal conductivity and ablation resistance. It can realize the structural integrity protection under the long-time scouring of high-temperature combustion gas, so as to meet the use requirements in fields such as solid rocket engine combustion chamber.

[0082] Various embodiments of the present application can take on a variety of scopes; it should be understood that a scope in the form of a range is described merely for the sake of convenience and brevity, and should not be construed as a rigid limitation of the scope of the present application; therefore, it should be considered that the range described has specifically disclosed all possible sub-ranges and single values within that range. For example, it should be considered that a range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integral) within the indicated range.

[0083] The foregoing is considered as illustrative only of the principles of the application. Numerous modifications and adaptations will be apparent to those skilled in the art in view of the foregoing description. Thus, the above description provided is not intended to limit the application to the particular embodiment shown. Many modifications, substitutions, and changes from the teachings of this application and in its details can be made by those skilled in the art without departing from the spirit and scope of the present application, which is defined by the following claims.

Claims

1. Aerogel thermal insulation composite, characterized in that, The aerogel thermal insulation composite material comprises the following components in parts by weight: The resin matrix 120~140 parts, the aerogel composite filler 20~30 parts, the vulcanizing agent 2~8 parts and the processing aid 8~15 parts; The resin matrix is composed of terpolymer ethylene-propylene rubber, phenolic resin and PVDF-HFP with a mass ratio of (95~105):(14~21):(10~15), and the molecular weight of the PVDF-HFP is 500,000~6,000,000; The aerogel composite filler is obtained by treating silica aerogel and zirconium oxide with a silane coupling agent.

2. The aerogel thermal insulation composite of claim 1, wherein, The aerogel thermal insulation composite material comprises the following components in parts by weight: The resin matrix 130 parts, the aerogel composite filler 27 parts, the vulcanizing agent 5 parts and the processing aid 12 parts.

3. The aerogel thermal insulation composite of claim 1, wherein, The resin matrix is composed of terpolymer ethylene-propylene rubber, phenolic resin and PVDF-HFP with a mass ratio of 100:17:

12.

4. The aerogel thermal insulation composite of claim 1, wherein, The PVDF-HFP includes at least one of PVDF-HFP with product model number PVDF-HFP 21216 and PVDF-HFP with product model number PVDF-HFP LBG.

5. The aerogel thermal insulation composite of claim 1, wherein, The preparation method of the aerogel composite filler Comprises the following processes: The silica aerogel with a bulk density of 25-50 kg / m 3 The first heating treatment is performed on the silica aerogel in an air atmosphere to obtain a modified silica aerogel. The modified silica aerogel, the first zirconium oxide with a particle size of 12~16 μm and the second zirconium oxide with a particle size of 1~3 μm are stirred and mixed according to a mass ratio of (9~13):(0.5~1):(2~3.5) to obtain a dry mixture; Under continuous stirring, the dry mixture is sprayed with a silane coupling agent water-alcohol solution with a pH of 4~5, and then subjected to a second heating treatment to obtain the aerogel composite filler.

6. The aerogel thermal insulation composite of claim 5, wherein, The working condition parameters of the first heating treatment include a temperature of 240~280℃ and a time of 30~60s; And / or, the working condition parameters of the second heating treatment include a temperature of 115~125℃ and a time of 60~120min.

7. The aerogel thermal insulation composite of claim 5, wherein, The preparation of the silane water-alcohol solution comprises the following processes: γ-aminopropyl triethoxysilane is added to a solvent composed of ethanol and water with a volume ratio of (3~5):1, followed by the addition of acetic acid to adjust the pH of the system to 4~5, and stirring for 20~40min to obtain the silane coupling agent water-alcohol solution containing 5~10% of γ-aminopropyl triethoxysilane by mass fraction; The amount of silane coupling agent used in the spraying process accounts for 1.0~2.5% of the weight of the dry mixture.

8. The aerogel thermal insulation composite of claim 1, wherein, The vulcanizing agent is composed of elemental sulfur and dicumyl peroxide with a mass ratio of (1~2):(3~4), and the processing aid includes paraffin oil.

9. A method of making the aerogel thermal insulation composite of any one of claims 1-8, wherein, The preparation method of the aerogel thermal insulation composite material comprises the following steps: The components in the aerogel thermal insulation composite material are mixed to obtain a mixed rubber; The mixed rubber is placed and then subjected to a vulcanization treatment to obtain the aerogel thermal insulation composite material.

10. The method of claim 9, wherein the aerogel thermal insulation composite is prepared by a process comprising: The working condition parameters of the mixing include a temperature of 115~120℃; And / or, the working condition parameters of the vulcanization treatment include a temperature of 155~165℃ and a pressure of 10~15Mpa.