Heat-insulating light ablation-resistant foamed ceramic silicone rubber material and preparation method thereof

Abstract

The invention belongs to the field of polymer composite materials, and relates to a heat-insulating light ablation-resistant foamed ceramic silicone rubber material and a preparation method thereof. The foamed silicone rubber is prepared by adding the self-made nano supported platinum catalyst, white carbon black and other additives, and the platinum catalyst is supported by nano fumed silica, so that the cellular structure of the silicone rubber is improved, and the foamed ceramic silicone rubber is endowed with good mechanical properties, water resistance and heat insulation. After being sintered at high temperature, the foamed ceramic silicone rubber provided by the invention can still keep a complete shape, is good in ceramic forming property, does not have the phenomena of cracking, powder falling and the like, and is excellent in structural stability. The ceramic foaming silicone rubber provided by the invention has been applied to fire-resistant cables and building fireproof materials to a certain extent, and also has very good application prospects in the fields of rail transit, aerospace, new energy automobiles, energy storage and the like.

Description

Technical Field

[0001] The invention belongs to the field of polymer composite materials, and in particular relates to a heat-insulating, lightweight, ablation-resistant foamed ceramic silicone rubber material and a preparation method thereof. Background Art

[0002] As people pay more and more attention to fire safety, in order to reduce the personal and property damage caused by fire in daily life, the use of fire retardant materials is an effective strategy to solve the fire hazard. Ablation-resistant thermal insulation composite materials are a very important type of fireproof material.

[0003] Silicone rubber not only has good thermal stability, but also produces less harmful gases during combustion, which causes less pollution to the environment. Silicone rubber is a semi-organic and semi-inorganic polymer compound whose main molecular chain consists of alternating silicon and oxygen atoms, and methyl or vinyl groups are connected to silicon atoms. Different groups such as phenyl, propyl, cyano, etc. can be introduced to change the physical and chemical properties of silicone rubber.

[0004] Due to the high bond energy of Si-O bonds in silicone rubber, silicone rubber itself has good thermal stability. In addition, when burning under high-temperature flames, Si-O bonds will be transformed into continuous, insulating network-like SiO2 ash covering the surface, thereby effectively preventing further ablation of the substrate. It has excellent biological inertness, weather resistance, thermal conductivity, air permeability, electrical insulation, high and low temperature resistance, flame retardancy, odorlessness, non-toxicity, and will not cause harm to the environment.

[0005] The ceramicization of silicone rubber makes it potential for use as a flame retardant material. However, the high ceramicization transition temperature means that the ceramicization process has little effect on the improvement of the fire resistance of silicone rubber at medium and low temperatures.

[0006] Foamed silicone rubber is a porous polymer elastomer that has been foamed. Silicone rubber has good high and low temperature resistance, flame retardancy and physiological inertness due to its special structure of silicon-oxygen bonds and the characteristics of generating non-toxic substances such as silicon dioxide, water and carbon dioxide after combustion. Foam materials have the characteristics of light weight, good cushioning, shock absorption, damping, sound insulation and thermal insulation. Therefore, foamed silicone rubber materials have the advantages of both ordinary silicone rubber and foaming materials, making them widely used in national defense, military industry and daily life. Summary of the invention

[0007] In order to address the defects and deficiencies in the application of organosilicon compounds in ablation-resistant materials, the present invention provides a lightweight ablation-resistant foamed ceramic silicone rubber material for thermal insulation and a preparation method thereof. The purpose is to foam the ceramic silicone rubber to give the foamed ceramic silicone rubber good mechanical properties, waterproofness, and thermal insulation.

[0008] The present invention is achieved by the following technical means:

[0009] The present invention first discloses a heat-insulating, lightweight, ablation-resistant foamed ceramic silicone rubber material, comprising the following raw materials in proportion by weight:

[0010] 60-80 parts of silicone rubber, 30-40 parts of vinyl silicone oil, 30-40 parts of hydrogen-containing silicone oil, 10 parts of white carbon black, 10-20 parts of hollow glass microspheres, 40-50 parts of aluminum hydroxide, 20-40 parts of mica powder, 40-50 parts of magnesium hydroxide, 10-20 parts of graphite, 20 parts of low-melting point glass powder of 300℃-600℃, 5-10 parts of titanium dioxide, 30-40 parts of fiber filler, 5 parts of carbon black, 10-20 parts of methyl silicone oil, 0.5 parts of toluene, 0.3-0.6 parts of inhibitor, and 0.5-0.8 parts of catalyst.

[0011] Furthermore, the vinyl silicone oil is selected from two or more of 1000 cSt, 500 cSt and 100 cSt.

[0012] Furthermore, the fiber filler is selected from three or more of carbon fiber, glass fiber, basalt fiber and aluminum silicate fiber.

[0013] Furthermore, the inhibitor is selected from: a combination of two or more of propargyl acetate, diallyl maleate, 1-alkynyl-1-cyclohexanol and 2-methyl-3-butyn-2-ol.

[0014] Furthermore, the catalyst is selected from: one or more of: silane transition metal complexes, chloroplatinic acid, palladium chloride, and platinum-loaded silica catalysts.

[0015] The present invention also discloses a method for preparing any of the above-mentioned lightweight, ablation-resistant foamed ceramic silicone rubber materials, comprising:

[0016] Mixing vinyl silicone oil and an inhibitor to obtain a first matrix;

[0017] Mixing hydrogen-containing silicone oil, toluene and a catalyst to obtain a second matrix;

[0018] The third matrix is ​​obtained by mixing silicone rubber, white carbon black, hollow glass microspheres, aluminum hydroxide, mica powder, magnesium hydroxide, graphite, low melting point glass powder, titanium dioxide, fiber filler, carbon black and methyl silicone oil;

[0019] The first matrix and the third matrix are mixed, and then the second matrix is ​​added and mixed evenly to obtain a mixture;

[0020] The mixture is subjected to ultrasonic treatment and then pre-curing treatment to obtain a lightweight, ablation-resistant foamed ceramic silicone rubber material.

[0021] Furthermore, the pre-curing treatment includes: placing the mixture after ultrasonic treatment at 80° C. to 100° C. for pre-curing for 1 to 2 minutes.

[0022] The invention also discloses a heat-insulating, lightweight, ablation-resistant foamed ceramic silicone rubber material prepared according to any of the above preparation methods.

[0023] The present invention also discloses an application of any of the above-mentioned lightweight ablation-resistant foamed ceramic silicone rubber materials in the production of foamed organic silicon fireproof materials, comprising:

[0024] The light-weight ablation-resistant foamed ceramic silicone rubber material is prepared at high temperature. The foamed silicone fireproof material is prepared by adjusting the content of the foaming agent to 10%, 15%, and 20%, and undergoing preheating treatment and curing treatment at high temperature to obtain the material.

[0025] Furthermore, the preheating condition at high temperature is: preheating at 100° C. for 1 to 2 minutes; and the curing condition is: curing at 110° C. to 130° C. for 8 to 10 minutes.

[0026] Furthermore, the application fields of the production of the foamed silicone fireproof material include but are not limited to: rail transportation, aerospace, new energy vehicles and energy storage.

[0027] The beneficial effects of the present invention are:

[0028] The present invention adopts a self-developed ceramic silicone resin, which forms a porcelain body after high-temperature sintering, while maintaining good thermal insulation and structural stability to meet the product use requirements. Under high temperature conditions, the silicone resin decomposes to generate SiO2, which reacts eutectically with the molten porcelain filler and flux system to finally form a ceramic body. By adding additives such as foaming agent and white carbon black, the effects of factors such as curing cross-linking temperature, foaming agent content and cross-linking agent content on the pore structure are studied in depth. In addition, nano-gas-phase silica is used to load platinum catalyst to improve the pore structure of silicone rubber, so that the pores are in a closed-cell form, thereby giving the foamed ceramic silicone rubber good elasticity, softness, waterproofness and thermal insulation. The foamed ceramic silicone rubber after high-temperature sintering can still maintain a complete shape, has good porcelain characteristics, no cracking or powdering phenomenon, shows excellent structural stability, and summarizes the law between porcelain structure and thermal protection performance. DETAILED DESCRIPTION

[0029] Unless otherwise specified, the scientific and technical terms used herein are understood according to the knowledge of ordinary technicians in the relevant fields.

[0030] The technical solution of the present invention is further described below, but is not limited thereto. Any equivalent replacement of the specific substances, formulas, processing temperatures, durations, etc. involved in the technical solution of the present invention does not deviate from the spirit and scope of the present invention and should be included in the protection scope of the present invention. The material performance testing methods in the following embodiments are: density test: refer to GB / T 6343-2009, compression test: refer to GB / T 7759-1996, thermal conductivity test: refer to GB / T10294-2008, flame retardant test: refer to GB / T 8333-2008. All the component materials used are commercially available products.

[0031] Embodiment 1:

[0032] The foamed organic silicon ceramic silicone rubber material of this embodiment is composed of the following raw materials in parts by weight:

[0033] 60g silicone rubber, 10g white carbon black, 10g hollow glass microspheres, 50g aluminum hydroxide, 40g mica powder, 30g 1.6% hydrogenated silicone oil, 40g magnesium hydroxide, 10g graphite, 20g low melting point glass powder, 5g titanium dioxide, 30g carbon fiber filler, 5g carbon black, 10g methyl silicone oil, 0.5g toluene, 40g vinyl silicone oil, 0.5g inhibitor, 0.8g catalyst;

[0034] Vinyl silicone oil is selected from: 500 cSt and 100 cSt, mixed in any proportion.

[0035] The fiber filler is selected from: glass fiber, basalt fiber and aluminum silicate fiber, mixed in any proportion.

[0036] The inhibitor is selected from the group consisting of propargyl acetate, 1-alkynyl-1-cyclohexanol and 2-methyl-3-butyn-2-ol, mixed in any proportion.

[0037] The catalyst is selected from: palladium chloride.

[0038] S1, adding white carbon black, hollow glass microspheres, aluminum hydroxide, mica powder, 1.6% hydrogenated silicone oil, magnesium hydroxide, graphite, low melting point glass powder, titanium dioxide, fiber filler, carbon black, and methyl silicone oil to silicone rubber. After manual pre-stirring, mechanical stirring is then performed for 10 minutes to mix evenly to obtain a first matrix;

[0039] S2, adding the inhibitor to the vinyl silicone oil and mixing it manually for 3 minutes to obtain the second matrix;

[0040] S3, adding a catalyst into toluene to uniformly dissolve the catalyst in the toluene, and then adding hydrogen-containing silicone oil to obtain a third monomer;

[0041] S4, then add the first matrix, the second matrix, and the third matrix into the flask in order, use mechanical stirring at a speed of 2000 rap / min for 2 to 3 minutes to fully mix the mixture to obtain the fourth matrix.

[0042] S5, the fourth matrix is ​​then centrifuged to achieve uniform dispersion of various materials in the fourth matrix through high-speed shearing, thereby giving full play to the role of various materials and removing bubbles mixed in during the stirring process. The centrifugal speed is 1500 rap / min and lasts for 5 minutes.

[0043] S6, filling the evenly dispersed fourth matrix into a polytetrafluoroethylene mold, first putting it into a 100° C. oven for 1 minute for pre-curing, and then putting the pre-cured fourth matrix into a 130° C. oven for 15 minutes for the final curing step.

[0044] After cooling to room temperature, the foamed ceramic silicone rubber material of this embodiment is demolded from the polytetrafluoroethylene mold.

[0045] Example 2

[0046] The specific preparation process is the same as in Example 1, except that the formula has changed, specifically:

[0047] 70g silicone rubber, 30g vinyl silicone oil, 30g 1.6% hydrogenated silicone oil, 10g white carbon black, 15g hollow glass microspheres, 40g aluminum hydroxide, 20g mica powder, 50g magnesium hydroxide, 20g graphite, 20g low melting point glass powder, 10g titanium dioxide, 40g fiber filler, 5g carbon black, 20g methyl silicone oil, 0.5g toluene, 0.3g inhibitor and 0.5g catalyst.

[0048] Vinyl silicone oil is selected from: 1000 cSt and 100 cSt, mixed in any proportion.

[0049] The fiber filler is selected from: carbon fiber, glass fiber, basalt fiber, mixed in any proportion.

[0050] The inhibitor is selected from: propargyl acetate, diallyl maleate, mixed in any proportion.

[0051] The catalyst is selected from: silane transition metal complexes.

[0052] Example 3

[0053] The specific preparation process is the same as in Example 1, except that the formula has changed, specifically:

[0054] 70g silicone rubber, 35g vinyl silicone oil, 35g 1.6% hydrogenated silicone oil, 10g white carbon black, 15g hollow glass microspheres, 45g aluminum hydroxide, 30g mica powder, 45g magnesium hydroxide, 15g graphite, 20g low melting point glass powder, 7.5g titanium dioxide, 35g fiber filler, 5g carbon black, 15g methyl silicone oil, 0.5g toluene, 0.4g inhibitor and 0.6g catalyst.

[0055] The vinyl silicone oil is selected from: 1000 cSt, 500 cSt and 100 cSt, mixed in any proportion.

[0056] The fiber filler is selected from: carbon fiber, glass fiber, basalt fiber and aluminum silicate fiber, mixed in any proportion.

[0057] The inhibitor is selected from the group consisting of propargyl acetate, diallyl maleate, 1-alkynyl-1-cyclohexanol and 2-methyl-3-butyn-2-ol, mixed in any proportion.

[0058] The catalyst is selected from: chloroplatinic acid, palladium chloride, mixed in any proportion.

[0059] Comparative Example 1:

[0060] The difference between this comparative example and Example 1 is that no hollow glass microspheres are added.

[0061] Comparative Example 2:

[0062] The difference between this comparative example and Example 1 is that no mica powder is added.

[0063] Comparative Example 3:

[0064] The difference between this comparative example and Example 1 is that no aluminum hydroxide is added.

[0065] The density and thermal conductivity of the materials obtained in the above Example 1 and Comparative Examples 1-3 were further measured according to GB / T 6343-2009 and GB / T10294-2008. The measurement results are shown in Table 1 below:

[0066] Table 1

[0067] <![CDATA[Density (g / cm 3 )]]> Thermal conductivity (W / m·K) Example 1 0.362 0.099 Comparative Example 1 0.406 0.163 Comparative Example 2 0.381 0.092 Comparative Example 3 0.376 0.0785

[0068] According to the results in Table 1, Example 1 has the best comprehensive performance, can provide lower thermal conductivity while maintaining low density, and is suitable for application scenarios with high requirements for thermal insulation and light weight.

[0069] Removing the hollow glass microspheres (Comparative Example 1) results in an increase in both the density and thermal conductivity of the material, which weakens the thermal insulation.

[0070] Removing the mica powder (Comparative Example 2) can slightly improve thermal insulation, but will result in an increase in density.

[0071] Removing aluminum hydroxide (Comparative Example 3) significantly improved thermal insulation, and despite the increase in density, the thermal conductivity was greatly reduced, indicating that aluminum hydroxide has a significant impact on thermal conductivity.

[0072] The materials obtained in Example 1 and Comparative Examples 1-3 were further subjected to compression performance test according to GB / T 7759-1996. The test results are shown in Table 2 below:

[0073] Table 2

[0074]

[0075]

[0076] According to the results in Table 2, Example 1 exhibits stable compression performance, which means that its formula design not only takes into account low density and thermal insulation performance, but also ensures the compression stability of the material.

[0077] After the hollow glass microspheres were removed from Comparative Example 1, the compression performance of the material deteriorated, indicating that the hollow glass microspheres play an important role in improving the material's resistance to compression deformation.

[0078] The removal of mica powder in Comparative Example 2 had little effect on the compression performance, but still showed a slightly higher compression deformation, indicating that mica powder had a certain contribution to the compression stability.

[0079] After removing aluminum hydroxide from Comparative Example 3, the compression performance of the material was improved, which may be because the presence of aluminum hydroxide has a certain negative impact on the overall flexibility and compression resistance of the material.

[0080] The material prepared in this example was subjected to a flame retardancy test according to GB / T 8333-2008. The test results are shown in Table 3:

[0081] Table 3

[0082] Test Results Example 1 <![CDATA[V0]]> Comparative Example 1 <![CDATA[V1]]> Comparative Example 2 <![CDATA[V1]]> Comparative Example 3 <![CDATA[V2]]>

[0083] According to the results in Table 3:

[0084] The flame retardant performance of Example 1 is the best, reaching V0 level, indicating that the formula design is reasonable, and the synergistic effect of aluminum hydroxide, hollow glass microspheres and mica powder is significant, which improves the thermal insulation, carbonization layer stability and flame retardant performance.

[0085] The flame retardant properties of Comparative Examples 1 and 2 are relatively poor, both of which are V1 level:

[0086] Comparative Example 1 (without hollow glass microspheres): The lack of microspheres results in decreased thermal insulation, accelerated heat conduction, and reduced flame retardancy.

[0087] Comparative Example 2 (without mica powder): The lack of mica powder weakens the oxygen isolation effect, the carbonized layer is unstable, and the flame retardant effect is affected.

[0088] The flame retardant performance of Comparative Example 3 is the worst, only V2 level: due to the lack of aluminum hydroxide, the endothermic decomposition and protective oxide layer functions are lost, and the flame retardant performance is significantly reduced.

[0089] It is understood that the above specific description of the present invention is only used to illustrate the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that the present invention can still be modified or replaced by equivalents to achieve the same technical effects; as long as the use requirements are met, they are within the protection scope of the present invention.

Claims

1. A heat-insulating, lightweight, ablation-resistant foamed ceramic silicone rubber material, comprising: 60-80 parts of silicone rubber, 30-40 parts of vinyl silicone oil, 30-40 parts of hydrogen-containing silicone oil, 10 parts of white carbon black, 10-20 parts of hollow glass microspheres, 40-50 parts of aluminum hydroxide, 20-40 parts of mica powder, 40-50 parts of magnesium hydroxide, 10-20 parts of graphite, 20 parts of low-melting point glass powder of 300℃-600℃, 5-10 parts of titanium dioxide, 30-40 parts of fiber filler, 5 parts of carbon black, 10-20 parts of methyl silicone oil, 0.5 parts of toluene, 0.3-0.6 parts of inhibitor, and 0.5-0.8 parts of catalyst.

2. The lightweight, ablation-resistant foamed ceramic silicone rubber material according to claim 1, wherein: The vinyl silicone oil is selected from two or more of 1000 cSt, 500 cSt and 100 cSt.

3. The lightweight, ablation-resistant foamed ceramic silicone rubber material according to claim 1, wherein: The fiber filler is selected from three or more of carbon fiber, glass fiber, basalt fiber and aluminum silicate fiber.

4. The lightweight, ablation-resistant foamed ceramic silicone rubber material according to claim 1, wherein: The inhibitor is selected from the group consisting of propargyl acetate, diallyl maleate, 1-alkynyl-1-cyclohexanol and 2-methyl-3-butyn-2-ol.

5. The lightweight, ablation-resistant foamed ceramic silicone rubber material according to claim 1, wherein: The catalyst is selected from: one or more of: silane transition metal complex, chloroplatinic acid, palladium chloride, and platinum-loaded silica catalyst.

6. A method for preparing the lightweight, ablation-resistant foamed ceramic silicone rubber material according to any one of claims 1 to 5, comprising: Mixing vinyl silicone oil and an inhibitor to obtain a first matrix; Mixing hydrogen-containing silicone oil, toluene and a catalyst to obtain a second matrix; The third matrix is ​​obtained by mixing silicone rubber, white carbon black, hollow glass microspheres, aluminum hydroxide, mica powder, magnesium hydroxide, graphite, low melting point glass powder, titanium dioxide, fiber filler, carbon black and methyl silicone oil; The first matrix and the third matrix are mixed, and then the second matrix is ​​added and mixed evenly to obtain a mixture; The mixture is subjected to ultrasonic treatment and then pre-curing treatment to obtain a lightweight, ablation-resistant foamed ceramic silicone rubber material.

7. The preparation method according to claim 6, wherein: The pre-curing treatment comprises: placing the mixture after ultrasonic treatment at 80° C. to 100° C. for pre-curing for 1 to 2 minutes.

8. A heat-insulating, lightweight, ablation-resistant foamed ceramic silicone rubber material prepared according to the preparation method of claim 6 or 7.

9. An application of the lightweight ablation-resistant foamed ceramic silicone rubber material according to any one of claims 1 to 5 and 8 in the production of foamed organic silicon fireproof materials, comprising: The light-weight ablation-resistant foamed ceramic silicone rubber material is prepared at high temperature. The foamed silicone fireproof material is prepared by adjusting the content of the foaming agent to 10%, 15%, and 20%, and undergoing preheating treatment and curing treatment at high temperature to obtain the material.

10. The use according to claim 9, wherein: The conditions for preheating at high temperature are: preheating at 100° C. for 1 to 2 minutes; The curing treatment conditions are: curing at 110° C. to 130° C. for 8 to 10 minutes.

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