Rubber type ablation-resistant thermal insulation material filled with PBO fibers and preparation method of rubber type ablation-resistant thermal insulation material

Abstract

The invention discloses a PBO fiber filled rubber type ablation-resistant thermal insulation material and a preparation method thereof, and belongs to the technical field of rubber. The adopted material components are as follows: 100 parts of rubber; 0-20 parts of an accelerant; 0.5 to 10 parts of a vulcanizing agent; 0 to 80 parts of PBO fiber; 0 to 50 parts of a reinforcing agent; 0-20 parts of a plasticizer; 0-30 parts of a flame retardant; 0 to 30 parts of ablation-resistant filler; and 0-20 parts of a ceramic forming filler. The PBO fibers are pretreated or / and non-pretreated PBO fibers. The invention discloses a preparation method of the rubber type ablation-resistant thermal insulation material. According to the method, the problem of stress concentration caused by non-uniform dispersion of the PBO fibers in a rubber matrix is solved especially through pretreatment of the PBO fibers, and the interface bonding force between the fibers and the heat insulation material matrix is effectively improved. According to the invention, the mechanical properties of the thermal insulation material in all directions can be basically kept consistent under the condition of more fiber filling parts.

Description

Technical Field

[0001] The invention belongs to the technical field of solid rocket engine thermal insulation layer materials, and prepares a solid rocket engine internal thermal insulation material with excellent mechanical properties and ablation resistance. Background Art

[0002] As a protective layer of the combustion chamber of a solid rocket engine, the flexible ablative material is located between the engine combustion chamber shell and the propellant grain, playing a role of heat insulation, preventing the shell from reaching a damage temperature that endangers its structural integrity. It has high-temperature ablation resistance, high-speed heat flow erosion resistance and good mechanical properties. It is an important component of high-performance solid propellant rocket engines in many aerospace and military applications. During the operation of the rocket engine, the insulation material will continue to degrade under the extreme environment of high temperature, high pressure and high-speed heat flow erosion, and form a carbonized layer. A temperature gradient is formed in the carbon layer, which slows down the transfer of heat and provides thermal protection for the shell. Therefore, the formation of a dense, complete and high-strength carbonized layer is crucial to having good ablation resistance.

[0003] The rubber matrix cannot form a solid carbonized layer after carbonization alone. In order to obtain an ablation-resistant material with excellent performance, an ablation-resistant fiber filler and other matching systems are usually added to the rubber matrix to give the material good mechanical properties, interface properties and ablation properties. Fillers have a very significant effect on ablative composites. Studying its mechanism of action and establishing the relationship between filler properties and composite material properties are conducive to better designing processing formulas and forming ablation-resistant materials with excellent performance. Fibers, as embedded skeleton materials, can fix more carbonized matrix, prevent the delamination and peeling of the carbonized matrix, effectively enhance the strength of the carbon layer, and improve the anti-erosion performance of the composite material to high-speed heat flow. The excellent thermal stability of the fiber can ensure that the carbonized matrix has a high mechanical strength, which is conducive to maintaining the fiber structure and strengthening the carbon layer, improving the anti-erosion performance. At the same time, it should also have a low density and thermal conductivity to achieve the lightweight and thermal insulation effect of flexible thermal insulation materials. Therefore, the thermal stability and interface interaction of the fiber are the key factors affecting the anti-erosion performance of thermal insulation materials, which have a guiding role in the research and application of the performance of ablation materials.

[0004] As asbestos fiber is carcinogenic, glass fiber and carbon fiber are easy to break during processing, and the reinforcing effect on the carbon layer structure is poor. At present, organic fibers are widely used to reinforce flexible insulation materials, such as aramid fiber (KF), polyimide fiber (PI), phenolic fiber (PF) and poly(p-phenylene benzobisoxazole) fiber (PBO). The main chain of PBO fiber molecules contains benzene rings and dioxazole ring groups, with high thermal stability and not easy to decompose. The initial decomposition temperature of PBO fiber is 643℃, the maximum decomposition rate temperature is 678℃, the residual carbon value at 800℃ is 64.7%, the limiting oxygen index is 68, and the modulus is 220GPa, which is much higher than the other three organic fibers. As a "four-super" super fiber with ultra-high strength, ultra-high modulus, ultra-high flame retardancy and ultra-high heat resistance, PBO fiber ranks first in heat resistance among high-performance organic fibers and is used as a new generation of reinforcing fiber for advanced composite materials in the aerospace field. Summary of the invention

[0005] The invention provides a solid rocket insulation layer material with excellent mechanical properties and ablation resistance and a preparation method thereof.

[0006] In order to improve the ablation resistance of thermal insulation materials and ensure that the thermal insulation materials have good mechanical properties to meet the actual working conditions of the engine, it is of great significance to develop a thermal insulation material with excellent ablation resistance and simple molding process. The present invention provides a PBO fiber-filled flexible solid rocket engine internal insulation material with excellent mechanical properties and ablation resistance, which can meet the design and use requirements of high-performance solid rocket engines.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] The present invention first provides an ablation-resistant flexible insulation material, comprising the following components in parts by weight: rubber, 100 parts; accelerator, 0 to 20 parts; vulcanizer, 0.5 to 10 parts; fiber, 0 to 80 parts and not 0; reinforcing agent, 0 to 50 parts; plasticizer, 0 to 20 parts; flame retardant, 0 to 30 parts; ablation-resistant filler, 0 to 30 parts; and porcelain-forming filler, 0 to 20 parts.

[0009] Preferably, the ablation-resistant flexible insulation material includes the following components in parts by weight: rubber, 100 parts; accelerator, 0 to 15 parts; vulcanizer, 0.5 to 5 parts; fiber, 0 to 30 parts and not 0; reinforcing agent, 0 to 30 parts; plasticizer, 0 to 20 parts; flame retardant, 0 to 20 parts; ablation-resistant filler, 0 to 20 parts; and porcelain-forming filler, 0 to 20 parts.

[0010] Furthermore, the rubber is one or more of natural rubber (NR), butadiene rubber (BR), styrene butadiene rubber (SBR), chloroprene rubber (CR), nitrile rubber (NBR), ethylene propylene rubber (EPM), graft-modified ethylene propylene rubber (g-EPM), ethylene propylene diene monomer rubber (EPDM), polyurethane elastomer (PU), silicone rubber (SR), fluororubber (FKM), polyphosphazene elastomer (PZ), chlorosulfonated polyethylene rubber (CSM), polysulfide rubber (PSR), and polyisoprene rubber (IR).

[0011] Furthermore, the accelerator is one or more of thiazoles, sulfenamides, thiurams, dithiocarbamates, guanidines and xanthates.

[0012] Furthermore, the vulcanizing agent is one or more of sulfur, organic peroxide, and metal oxide.

[0013] Furthermore, the reinforcing agent is one or more of carbon black, white carbon black, silicate, calcium carbonate, montmorillonite, and zinc oxide.

[0014] Furthermore, the plasticizer is one or more of liquid ethylene propylene rubber, liquid hydroxyl-terminated polybutadiene, aliphatic hydrocarbons, cycloalkanes, aromatic hydrocarbon process oils, phthalates, fatty dibasic acid esters, fatty acids, phosphates, polyesters, epoxies, and chlorine-containing types.

[0015] Furthermore, the flame retardant is one or more of an inorganic flame retardant (such as aluminum hydroxide, magnesium hydroxide, boron compounds, molybdenum compounds, antimony trioxide), a phosphorus flame retardant (ammonium polyphosphate, tricresyl phosphate, phosphite), and an organic halogen flame retardant (such as decabromodiphenylethane, decabromodiphenyl ether (DBDPO), tetrabromobisphenol A bis(2,3-dialkylpropyl) ether (TBAB), octabromodiphenyl ether (OBDPO), chlorinated paraffin, tetrachlorophthalic anhydride, tetrachlorobisphenol A, hexachlorocyclopentadiene, bis(hexachlorocyclopentadiene)cyclooctane, perchlorocyclopentadecane, tetrachlorophthalic anhydride, and chlorendic acid).

[0016] Furthermore, the ablation-resistant filler is a phenolic resin, such as one or more of boron phenolic resin (boron phenolic resin TH-390, boron phenolic resin FBO-389, boron phenolic resin SFB, boron phenolic resin THC-400), aminophenolic resin, barium phenolic resin, clay, montmorillonite, phenolic hollow microspheres, silica or glass microspheres, and cork.

[0017] Furthermore, the ceramic-forming filler is one or more of silazane and siloxane.

[0018] Furthermore, the fiber is one or more of pulp, short-cut fiber, long fiber and fiber cloth containing poly(p-phenylene benzobisoxazole) structure, that is, PBO fiber.

[0019] The thermal insulation material formula of the solid rocket engine containing PBO fiber prepared by the present invention can contain not only PBO fiber but also one or more of carbon fiber, glass fiber, ceramic fiber, aramid fiber, aramid pulp, aramid fiber, aramid pulp, phenolic fiber, polyimide fiber and asbestos fiber.

[0020] In the present invention, the fiber may be surface pretreated or may not be surface treated.

[0021] Fiber pretreatment methods include dispersion treatment and / or chemical modification. Dispersion treatment is conducive to the uniform distribution of fibers in the matrix. In order to further improve the interface between the fiber and the matrix and improve the mechanical properties of the thermal insulation material, the fiber surface can be chemically modified.

[0022] The fiber pretreatment preparation process is as follows:

[0023] (1) Fiber dispersion treatment: break up the fibers to improve their uniform distribution in the matrix.

[0024] (2) Fiber chemical modification: After removing impurities from the surface of PBO fibers (which can be scattered or not), the fibers are dried and then treated with chemical modifiers or plasma etching to increase the number of polar functional groups on the fiber surface and improve the surface free energy of the fibers. This can enhance the interfacial bonding between the fibers and the matrix, giving the flexible insulation material excellent mechanical properties and ablation resistance.

[0025] Furthermore, the chemical modifier is a mixture of a coupling agent, anhydrous ethanol and distilled water, wherein the concentration of the coupling agent is 0 to 40% and is not 0.

[0026] Furthermore, the coupling agent is one or more of hydrocarbon silanes.

[0027] The present invention further provides a method for preparing the above-mentioned ablation-resistant flexible thermal insulation material, comprising the following steps:

[0028] Step S1, weighing according to the formula, firstly plasticating the raw rubber on an open mixing mill;

[0029] Step S2, after being evenly mixed, add accelerator, flame retardant, ablation-resistant filler, fiber, reinforcing agent, plasticizer, and porcelain-forming filler in sequence, and pass through several times;

[0030] Step S3, finally adding the vulcanizing agent, mixing evenly and then thinning for several times, producing a sheet for standby use, and vulcanizing and molding by a flat vulcanizing machine to prepare a PBO fiber-filled ablation-resistant flexible insulation material.

[0031] Furthermore, before vulcanization, the mixed rubber material is conditioned at room temperature for not less than 12 hours.

[0032] Furthermore, the vulcanization conditions are as follows: a vulcanization temperature of 130° C. to 170° C., a vulcanization time of 30 min to 100 min, and a vulcanization pressure of 5 MPa to 30 MPa.

[0033] The method for preparing a PBO fiber-filled ablation-resistant flexible thermal insulation material provided by the present invention has the following beneficial effects:

[0034] (1) The PBO fiber used in the present invention has the characteristics of high strength, high modulus, excellent heat resistance and flame retardancy, which is conducive to giving full play to the high performance advantages of the fiber as a skeleton material, and preparing a rocket engine internal insulation material with excellent mechanical properties and ablation resistance.

[0035] (2) The preparation process adopted by the present invention can maintain good mechanical properties even when more fiber is filled, that is, the mechanical properties in the perpendicular calendering direction and the parallel calendering direction are basically the same, which solves the problem of excessive difference in mechanical properties of fiber-filled rubber materials in different directions, ensures the performance reliability of the insulation material under different conditions, and can adapt to the special requirements of the engine for the mechanical properties of the insulation layer.

[0036] (3) This product has excellent processing performance and good fluidity. In addition to being used as the thermal insulation material in solid rocket engines, it also has good application prospects in the field of civilian thermal insulation flexible materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The embodiments and comparative examples of the present invention are further described in conjunction with the accompanying drawings.

[0038] Figure 1 Surface microscopic morphology of the fibers used in Example 8 and Comparative Examples 1, 2, and 4.

[0039] Figure 2 Microscope pictures showing the dispersion of fibers in Example 8 and Comparative Examples 1, 2, and 4.

[0040] Figure 3 The microscopic morphology of the tensile cross section of the samples of Example 8 and Comparative Examples 1, 2, and 4 are shown.

[0041] Figure 4 These are the microscopic morphology of the tensile cross-section of Example 39 and Example 14 before and after fiber modification, and the dispersion of the fibers in the matrix.

[0042] Figure 5 These are the microscopic morphologies of (a) the carbon layer surface and (b) the carbon layer cross section of the sample in Example 3 after ablation.

[0043] Figure 6 This is a diagram showing the bonding effect of the sample in Example 15 with metal steel and aluminum. DETAILED DESCRIPTION

[0044] In order to enable those skilled in the art to better understand and implement the technical solution of the present invention, the present invention is further described below in conjunction with specific embodiments. However, the embodiments are only intended to illustrate the present invention and not to limit the present invention.

[0045] Example 1

[0046] EPDM rubber, 100 parts; dicumyl peroxide, 5 parts; PBO-pulp, 20 parts; white carbon black, 40 parts; dioctyl sebacate, 10 parts. The specific implementation method is as follows:

[0047] The EPDM raw rubber is plasticized on an open mixing mill for 3 minutes. After being evenly mixed, PBO-pulp, white carbon black and dioctyl sebacate are added in sequence. The temperature of the rubber compound is controlled at about 40°C, and thinned 10 times. Diisopropylbenzene peroxide is added, and the rubber compound is mixed evenly and thinned 10 times before being produced into sheets. After adjusting at room temperature for 24 hours, hot-press vulcanization is performed at 160°C for 50 minutes and the vulcanization pressure is 10 MPa to prepare the ablation-resistant EPDM thermal insulation material.

[0048] Example 2

[0049] SR rubber, 100 parts; dicumyl peroxide, 2 parts; PBO-3mm, 15 parts; white carbon black, 35 parts; boron phenolic resin TH-390, 5 parts. The specific implementation method is as follows:

[0050] The SR raw rubber was plasticized on an open mixing mill for 5 minutes. After being evenly mixed, boron phenolic resin TH-390, PBO-3mm and white carbon black were added in sequence. The temperature of the rubber compound was controlled at about 60°C, and thinned 10 times. Diisopropylbenzene peroxide was added, and the mixture was evenly thinned 10 times and then sheets were produced. After adjusting at room temperature for 24 hours, hot-press vulcanization was performed at 140°C for 50 minutes and the vulcanization pressure was 10 MPa to prepare the ablation-resistant SR thermal insulation material.

[0051] Example 3

[0052] EPDM rubber, 100 parts; thiazole accelerator, 15 parts; sulfur / dicumyl peroxide, 3 parts; PBO-3mm, 25 parts; white carbon black, 30 parts; aluminum hydroxide, 30 parts. The specific implementation method is as follows:

[0053] The EPDM raw rubber is plasticized on an open mixing mill for 3 minutes. After being evenly mixed, thiazole accelerators, aluminum hydroxide, PBO-3mm and white carbon black are added in sequence. The temperature of the rubber compound is controlled at about 40°C, and thinned through 10 times. The vulcanizing agent is added, and the rubber compound is evenly mixed and thinned through 10 times. After being sheeted, it is adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 160°C for 50 minutes with a vulcanization pressure of 10 MPa to prepare the ablation-resistant EPDM thermal insulation material.

[0054] Example 4

[0055] NBR, 100 parts; sulfur, 2 parts; PBO-3mm, 30 parts; white carbon black, 25 parts; dibutyl phthalate, 12 parts. The specific implementation method is as follows:

[0056] The NBR raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, PBO-3mm, white carbon black and dibutyl phthalate are added in sequence. The temperature of the rubber compound is controlled at about 60°C, and thinned 10 times. Sulphur is added, and the rubber compound is evenly mixed and thinned 10 times. After being sheeted, it is adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 160°C for 70 minutes with a vulcanization pressure of 15 MPa to prepare the ablation-resistant NBR thermal insulation material.

[0057] Example 5

[0058] EPDM rubber, 100 parts; thiazole accelerator, 13 parts; dicumyl peroxide, 4 parts; PBO-6mm, 18 parts; white carbon black, 30 parts; dioctyl sebacate, 12 parts. The specific implementation method is as follows:

[0059] The EPDM raw rubber was plasticized on an open mixing mill for 3 minutes. After being evenly mixed, thiazole accelerators, PBO-6mm, white carbon black, and dioctyl sebacate were added in sequence. The temperature of the rubber compound was controlled at about 40°C, and thinned 10 times. Diisopropylbenzene peroxide was added, and the rubber compound was evenly mixed and thinned 10 times before being produced into sheets. After adjusting at room temperature for 24 hours, hot-press vulcanization was performed at 160°C for 50 minutes, and the vulcanization pressure was 10 MPa, to thereby prepare the ablation-resistant EPDM thermal insulation material.

[0060] Example 6

[0061] EPDM rubber, 100 parts; thiazole accelerator, 6 parts; sulfur / dicumyl peroxide, 3.5 parts; PBO-9mm, 12 parts; white carbon black, 40 parts; magnesium hydroxide, 20 parts. The specific implementation method is as follows:

[0062] The EPDM raw rubber is plasticized on an open mixing mill for 3 minutes. After being evenly mixed, thiazole accelerators, magnesium hydroxide, PBO-9mm and white carbon black are added in sequence. The temperature of the rubber compound is controlled at about 40°C, and thinned 10 times. Sulfur / diisopropylbenzene peroxide is added, and the rubber compound is evenly mixed and thinned 10 times. After being sheeted, it is adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 160°C for 50 minutes with a vulcanization pressure of 10 MPa to prepare the ablation-resistant EPDM thermal insulation material.

[0063] Example 7

[0064] SR rubber, 100 parts; 2,5-dimethyl-2,5-bis-(tert-butylperoxy)hexane, 3 parts; PBO-3mm, 15 parts; white carbon black, 20 parts; aminophenol-formaldehyde resin, 15 parts. The specific implementation method is as follows:

[0065] The SR raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, aminophenol-formaldehyde resin, PBO-3mm and white carbon black are added in sequence. The temperature of the rubber compound is controlled at about 60°C, and thinned 10 times. 2,5-dimethyl-2,5-bis-(tert-butylperoxy)hexane is added, and the mixture is evenly mixed and thinned 10 times. The sheet is produced after adjusting at room temperature for 24 hours, and hot-pressed and vulcanized at 140°C for 50 minutes with a vulcanization pressure of 10 MPa to prepare the ablation-resistant SR thermal insulation material.

[0066] Example 8

[0067] EPDM rubber, 100 parts; guanidine accelerator, 10 parts; sulfur, 3.5 parts; PBO-3mm, 5 parts; white carbon black, 35 parts; paraffin oil, 7 parts. The specific implementation method is as follows:

[0068] The fiber processing equipment was used to centrifugally disperse the above spare fibers with a fan, and the fan speed was controlled to be 1500r / min. The dispersed fibers were first soaked in anhydrous ethanol for 12 hours, washed with distilled water, and finally dried in a vacuum oven at 120°C for 24 hours. The fiber modification was carried out as follows: 1) The fiber was mixed with anhydrous ethanol and distilled water mixture with a coupling agent (vinyl triethoxysilane) concentration of 30%; 2) Heated reaction for 4 hours (60°C); 3) The treated fiber was washed 3 times with acetone and distilled water, and dried at 120°C for 24 hours.

[0069] The EPDM raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, guanidine accelerators, PBO-3mm, white carbon black and paraffin oil are added in sequence. The temperature of the rubber compound is controlled at about 60°C, and thinned 15 times. Sulphur is added, and the rubber compound is evenly mixed and thinned 15 times. After being sheeted, it is adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 150°C for 40 minutes with a vulcanization pressure of 15 MPa to prepare the ablation-resistant EPDM thermal insulation material.

[0070] Example 9

[0071] NBR, 100 parts; thiazole accelerator, 7 parts; dicumyl peroxide, 3 parts; PBO-3mm, 20 parts; white carbon black, 25 parts; dibutyl phthalate, 15 parts; barium phenolic resin, 20 parts. The specific implementation method is as follows:

[0072] The fiber treatment equipment was used to centrifugally disperse the above spare fibers with a fan, and the fan speed was controlled to be 1500r / min. The dispersed fibers were first soaked in anhydrous ethanol for 12 hours, then washed with distilled water, and finally dried in a vacuum oven at 120°C for 24 hours. The fiber modification was carried out as follows: 1) The fiber was mixed with anhydrous ethanol and distilled water mixture with a coupling agent (vinyl trimethoxysilane) concentration of 10%; 2) Heated reaction for 4 hours (60°C); 3) The treated fiber was washed 3 times with acetone and distilled water, and dried at 120°C for 24 hours.

[0073] The NBR raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, thiazole accelerator, barium phenolic resin, PBO-3mm, white carbon black and dibutyl phthalate are added in sequence. The temperature of the rubber compound is controlled at about 60°C, and thinned 10 times. Diisopropylbenzene peroxide is added, and the rubber compound is evenly mixed and thinned 10 times. After being sheeted, it is adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 160°C for 70 minutes with a vulcanization pressure of 15 MPa to prepare the ablation-resistant NBR thermal insulation material.

[0074] Example 10

[0075] SR rubber, 100 parts; 2,5-dimethyl-2,5-bis-(tert-butylperoxy)hexane, 3 parts; PBO-3mm, 15 parts; white carbon black, 20 parts; aminophenol-formaldehyde resin, 15 parts. The specific implementation method is as follows:

[0076] The fiber processing equipment was used to centrifugally disperse the above spare fibers with a fan, and the fan speed was controlled to be 1500r / min. The dispersed fibers were first soaked in anhydrous ethanol for 12 hours, then washed with distilled water, and finally dried in a vacuum oven at 120°C for 24 hours. The fiber modification was carried out as follows: 1) The fiber was mixed with anhydrous ethanol and distilled water mixture with a coupling agent (vinyl tri(β-methoxyethoxy) silane) concentration of 20%; 2) Heated reaction for 4 hours (60°C); 3) The treated fiber was washed 3 times with acetone and distilled water, and dried at 120°C for 24 hours.

[0077] The SR raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, aminophenol-formaldehyde resin, PBO-3mm and white carbon black are added in sequence. The temperature of the rubber compound is controlled at about 60°C, and thinned 10 times. 2,5-dimethyl-2,5-bis-(tert-butylperoxy)hexane is added, and the mixture is evenly mixed and thinned 10 times. The sheet is produced after adjusting at room temperature for 24 hours, and hot-pressed and vulcanized at 140°C for 50 minutes with a vulcanization pressure of 10 MPa to prepare the ablation-resistant SR thermal insulation material.

[0078] Embodiment 11

[0079] EPDM rubber, 100 parts; thiuram accelerator, 10 parts; dicumyl peroxide, 2 parts; PBO-3mm, 15 parts; white carbon black, 25 parts; tributyl phosphate, 9 parts; ammonium polyphosphate, 12 parts. The specific implementation method is as follows:

[0080] The EPDM raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, thiuram accelerator, ammonium polyphosphate, fiber, reinforcing agent and tributyl phosphate are added in sequence. The temperature of the rubber compound is controlled at about 60°C, and thinned 15 times. Dicumyl peroxide is added, and the rubber compound is evenly mixed and thinned 15 times. After being sheeted, it is adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 150°C for 40 minutes with a vulcanization pressure of 15 MPa to prepare the ablation-resistant EPDM thermal insulation material.

[0081] Example 12

[0082] EPDM rubber, 100 parts; thiazole accelerator, 15 parts; sulfur / diisopropylbenzene peroxide, 2.5 parts; PBO-3mm, 20 parts; white carbon black, 20 parts; decabromodiphenylethane, 15 parts. The specific implementation method is as follows:

[0083] The EPDM raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, thiazole accelerators, decabromodiphenylethane, PBO-3mm and white carbon black are added in sequence. The temperature of the rubber compound is controlled at about 60°C, and thinned through 15 times. Sulfur / diisopropylbenzene peroxide is added, and the rubber compound is evenly mixed and thinned through 15 times. After being sheeted, it is adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 150°C for 40 minutes with a vulcanization pressure of 15 MPa to prepare the ablation-resistant EPDM thermal insulation material.

[0084] Embodiment 13

[0085] NBR, 100 parts; thiuram accelerator, 10 parts; sulfur, 4 parts; PBO-6mm, 8 parts; white carbon black, 35 parts; tributyl phosphate, 8 parts; ammonium polyphosphate, 25 parts; aminophenol-formaldehyde resin, 20 parts. The specific implementation method is as follows:

[0086] The NBR raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, thiuram accelerators, ammonium polyphosphate, aminophenol-formaldehyde resin, PBO-6mm, white carbon black and tributyl phosphate are added in sequence. The temperature of the rubber compound is controlled at about 60°C, and thinned 10 times. Sulphur is added, and the rubber compound is evenly mixed and thinned 10 times. After being sheeted, it is adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 160°C for 70 minutes with a vulcanization pressure of 15 MPa to prepare the ablation-resistant NBR thermal insulation material.

[0087] Embodiment 14

[0088] EPDM rubber, 100 parts; sulfonamide accelerator, 15 parts; sulfur / diisopropylbenzene peroxide, 5 parts; PBO-3mm, 20 parts; white carbon black, 35 parts; paraffin oil, 7 parts. The specific implementation method is as follows:

[0089] The fiber treatment equipment was used to centrifugally disperse the above spare fibers with a fan, and the fan speed was controlled to be 1500r / min. The dispersed fibers were first soaked in anhydrous ethanol for 12 hours, then washed with distilled water, and finally dried in a vacuum oven at 120°C for 24 hours. The fiber modification was carried out as follows: 1) The fiber was mixed with anhydrous ethanol and distilled water mixture with a coupling agent (vinyl trimethoxysilane) concentration of 35%; 2) Heated reaction for 4 hours (60°C); 3) The treated fiber was washed 3 times with acetone and distilled water, and dried at 120°C for 24 hours.

[0090] The EPDM raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, sulfonamide accelerators, PBO-3mm, white carbon black and paraffin oil are added in sequence. The temperature of the rubber compound is controlled at about 70°C, and thinned 20 times. Sulfur / diisopropylbenzene peroxide is added, and the rubber compound is evenly mixed and thinned 20 times. After being sheeted, it is adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 170°C for 55 minutes with a vulcanization pressure of 10 MPa to prepare the ablation-resistant EPDM thermal insulation material.

[0091] Embodiment 15

[0092] EPDM rubber, 100 parts; thiazole accelerator, 12 parts; dicumyl peroxide, 3 parts; PBO-pulp, 25 parts; white carbon black, 25 parts; paraffin oil, 15 parts; boron phenolic resin FBO-389, 20 parts. The specific implementation method is as follows:

[0093] The EPDM raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, thiazole accelerator, boron phenolic resin FBO-389, fiber, reinforcing agent and plasticizer are added in sequence. The temperature of the rubber compound is controlled at about 50°C, and thinned through 15 times. The vulcanizing agent is added, and the rubber compound is evenly mixed and thinned through 15 times. After being sheeted, it is adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 160°C for 60 minutes with a vulcanization pressure of 15 MPa to prepare the ablation-resistant EPDM thermal insulation material.

[0094] Example 16

[0095] EPDM rubber, 100 parts; sulfonamide accelerator, 16 parts; sulfur / dicumyl peroxide, 4 parts; PBO-3mm, 20 parts; white carbon black, 20 parts; boron phenolic resin SFB, 10 parts. The specific implementation method is as follows:

[0096] The EPDM raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, sulfonamide accelerators, boron phenolic resin SFB, PBO-3mm and white carbon black are added in sequence. The temperature of the rubber compound is controlled at about 50°C, and thinned through 15 times. Sulfur / diisopropylbenzene peroxide is added, and the mixture is evenly thinned through 15 times. After being sheeted, it is adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 160°C for 60 minutes with a vulcanization pressure of 10 MPa to prepare the ablation-resistant EPDM thermal insulation material.

[0097] Embodiment 17

[0098] NBR, 100 parts; thiazole accelerator, 7 parts; dicumyl peroxide, 3 parts; PBO-3mm, 20 parts; white carbon black, 25 parts; dibutyl phthalate, 15 parts; barium phenolic resin, 20 parts. The specific implementation method is as follows:

[0099] The NBR raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, thiazole accelerator, barium phenolic resin, PBO-3mm, white carbon black and dibutyl phthalate are added in sequence. The temperature of the rubber compound is controlled at about 60°C, and thinned 10 times. Diisopropylbenzene peroxide is added, and the rubber compound is evenly mixed and thinned 10 times. After being sheeted, it is adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 160°C for 50 minutes with a vulcanization pressure of 15 MPa to prepare the ablation-resistant NBR thermal insulation material.

[0100] Embodiment 18

[0101] EPDM rubber, 100 parts; sulfur / dicumyl peroxide, 2.5 parts; PBO-3mm, 18 parts; white carbon black, 30 parts; ammonium polyphosphate, 18 parts; boron phenolic resin TH-390, 20 parts. The specific implementation method is as follows:

[0102] The EPDM raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, ammonium polyphosphate, boron phenolic resin TH-390, PBO-3mm and white carbon black are added in sequence. The temperature of the rubber compound is controlled at about 50°C, and thinned through 15 times. Sulfur / diisopropylbenzene peroxide is added, and the mixture is evenly thinned through 15 times. After being adjusted at room temperature for 24 hours, the mixture is hot-pressed and vulcanized at 160°C for 60 minutes with a vulcanization pressure of 15 MPa to prepare the ablation-resistant EPDM thermal insulation material.

[0103] Embodiment 19

[0104] EPDM rubber, 100 parts; thiuram accelerator, 7 parts; dicumyl peroxide, 3.5 parts; PBO-6mm, 15 parts; white carbon black, 25 parts; boron phenolic resin THC-400, 5 parts. The specific implementation method is as follows:

[0105] The EPDM raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, thiuram accelerator, boron phenolic resin THC-400, PBO-6mm and white carbon black are added in sequence. The temperature of the rubber compound is controlled at about 50°C, and thinned through 15 times. Diisopropylbenzene peroxide is added, and the rubber compound is evenly mixed and thinned through 15 times. After being sheeted, it is adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 160°C for 50 minutes with a vulcanization pressure of 10 MPa to prepare the ablation-resistant EPDM thermal insulation material.

[0106] Embodiment 20

[0107] SR rubber, 100 parts; thiazole accelerator, 15 parts; dicumyl peroxide, 4 parts; PBO-6mm, 15 parts; carbon black, 40 parts. The specific implementation method is as follows:

[0108] The SR raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, thiazole accelerator, PBO-6mm and carbon black are added in sequence. The temperature of the rubber compound is controlled at about 60°C, and thinned 10 times. Diisopropylbenzene peroxide is added, and the rubber compound is evenly mixed and thinned 10 times. After being discharged from the sheet, it is adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 140°C for 50 minutes with a vulcanization pressure of 10 MPa to prepare the ablation-resistant SR thermal insulation material.

[0109] Embodiment 21

[0110] EPDM rubber, 100 parts; sulfur, 1.5 parts; PBO-6mm, 30 parts; white carbon black, 35 parts; dioctyl sebacate, 9 parts; decabromodiphenylethane, 20 parts; boron phenolic resin FBO-389, 6 parts. The specific implementation method is as follows:

[0111] The EPDM raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, decabromodiphenyl ethane, boron phenolic resin FBO-389, PBO-6mm, white carbon black, and dioctyl sebacate are added in sequence. The temperature of the rubber compound is controlled at about 50°C, and thinned 10 times. Sulphur is added, and the rubber compound is evenly mixed and thinned 10 times before being produced into sheets. After adjusting at room temperature for 24 hours, hot-press vulcanization is performed at 160°C for 50 minutes, and the vulcanization pressure is 10 MPa, to thereby prepare the ablation-resistant EPDM thermal insulation material.

[0112] Embodiment 22

[0113] EPDM rubber, 100 parts; sulfur / diisopropylbenzene peroxide, 2 parts; PBO-3mm, 28 parts; white carbon black, 40 parts; paraffin oil, 15 parts; boron phenolic resin FBO-389, 12 parts. The specific implementation method is as follows:

[0114] The EPDM raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, boron phenolic resin FBO-389, PBO-3mm, white carbon black and paraffin oil are added in sequence. The temperature of the rubber compound is controlled at about 50°C, and thinned 10 times. Sulfur / diisopropylbenzene peroxide is added, and the mixture is evenly thinned 10 times. After being sheeted, it is adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 150°C for 50 minutes with a vulcanization pressure of 10 MPa to prepare the ablation-resistant EPDM thermal insulation material.

[0115] Embodiment 23

[0116] EPDM rubber, 100 parts; thiazole accelerator, 8 parts; sulfur / dicumyl peroxide, 3 parts; PBO-3mm, 25 parts; white carbon black, 30 parts; boron phenolic resin FBO-389, 18 parts. The specific implementation method is as follows:

[0117] The EPDM raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, thiazole accelerators, boron phenolic resin FBO-389, PBO-3mm and white carbon black are added in sequence. The temperature of the rubber compound is controlled at about 50°C, and thinned through 10 times. Sulfur / diisopropylbenzene peroxide is added, and the rubber compound is evenly mixed and thinned through 10 times. After being sheeted, it is adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 160°C for 50 minutes with a vulcanization pressure of 10 MPa to prepare the ablation-resistant EPDM thermal insulation material.

[0118] Embodiment 24

[0119] SR rubber, 100 parts; thiuram accelerator, 10 parts; benzoyl peroxide, 3 parts; PBO-9mm, 20 parts; carbon black, 20 parts; aminophenol-formaldehyde resin, 30 parts. The specific implementation method is as follows:

[0120] The SR raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, thiuram accelerator, aminophenol-formaldehyde resin, PBO-9mm and carbon black are added in sequence. The temperature of the rubber compound is controlled at about 60°C, and thinned 10 times. Benzoyl peroxide is added, and the rubber compound is evenly mixed and thinned 10 times. After being sheeted, it is adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 140°C for 50 minutes with a vulcanization pressure of 10 MPa to prepare the ablation-resistant SR thermal insulation material.

[0121] Embodiment 25

[0122] EPDM rubber, 100 parts; dicumyl peroxide, 5 parts; PBO-3mm, 20 parts; white carbon black, 40 parts; ammonium polyphosphate, 30 parts. The specific implementation method is as follows:

[0123] The EPDM raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, ammonium polyphosphate, PBO-3mm and white carbon black are added in sequence. The temperature of the rubber compound is controlled at about 50°C, and thinned 10 times. Dicumyl peroxide is added, and the rubber compound is evenly mixed and thinned 10 times. After being discharged from the sheet, it is adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 150°C for 70 minutes with a vulcanization pressure of 5 MPa to prepare the ablation-resistant EPDM thermal insulation material.

[0124] Embodiment 26

[0125] EPDM rubber, 100 parts; thiazole accelerator, 15 parts; benzoyl peroxide, 4.5 parts; PBO-6mm, 10 parts; white carbon black, 30 parts; dioctyl sebacate, 8 parts; aluminum hydroxide, 20 parts. The specific implementation method is as follows:

[0126] The EPDM raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, thiazole accelerators, aluminum hydroxide, PBO-6mm, white carbon black, and dioctyl sebacate are added in sequence. The temperature of the rubber compound is controlled at about 50°C, and thinned 10 times. Benzoyl peroxide is added, and the rubber compound is evenly mixed and thinned 10 times. After being sheeted, it is adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 150°C for 70 minutes with a vulcanization pressure of 5 MPa to prepare the ablation-resistant EPDM thermal insulation material.

[0127] Embodiment 27

[0128] EPDM rubber, 100 parts; sulfur / benzoyl peroxide, 3 parts; PBO-3mm, 30 parts; white carbon black, 35 parts; decabromodiphenylethane, 10 parts. The specific implementation method is as follows:

[0129] The EPDM raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, decabromodiphenyl ethane, PBO-3mm and white carbon black are added in sequence. The temperature of the rubber compound is controlled at about 50°C, and thinned 10 times. Sulfur / benzoyl peroxide is added, and the mixture is evenly thinned 10 times. After being sheeted, it is adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 150°C for 70 minutes with a vulcanization pressure of 5 MPa to prepare the ablation-resistant EPDM thermal insulation material.

[0130] Embodiment 28

[0131] NBR, 100 parts; guanidine accelerator, 15 parts; sulfur, 2 parts; PBO-3mm, 20 parts; white carbon black, 25 parts; aminophenol-formaldehyde resin, 10 parts; silazane, 15 parts. The specific implementation method is as follows:

[0132] The NBR raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, guanidine accelerators, aminophenol-formaldehyde resin, PBO-3mm, white carbon black and silazane are added in sequence. The temperature of the rubber compound is controlled at about 60°C, and thinned 10 times. Sulphur is added, and the rubber compound is evenly mixed and thinned 10 times before being sheeted. After adjusting at room temperature for 24 hours, hot-press vulcanization is performed at 160°C for 50 minutes, and the vulcanization pressure is 15 MPa, to prepare the ablation-resistant NBR thermal insulation material.

[0133] Embodiment 29

[0134] EPDM rubber, 100 parts; guanidine accelerator, 12 parts; sulfur / dicumyl peroxide, 2 parts; PBO-3mm, 35 parts; white carbon black, 25 parts; paraffin oil, 18 parts; barium phenolic resin, 20 parts. The specific implementation method is as follows:

[0135] The EPDM raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, guanidine accelerators, barium phenolic resin, PBO-3mm, white carbon black and paraffin oil are added in sequence. The temperature of the rubber compound is controlled at about 50°C, and thinned 10 times. Sulfur / diisopropylbenzene peroxide is added, and the rubber compound is evenly mixed and thinned 10 times. After being sheeted, it is adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 150°C for 60 minutes with a vulcanization pressure of 5 MPa to prepare the ablation-resistant EPDM thermal insulation material.

[0136] Embodiment 30

[0137] SR rubber, 100 parts; guanidine accelerator, 7 parts; 2,5-dimethyl-2,5-bis-(tert-butylperoxy)hexane, 4 parts; PBO-3mm, 25 parts; white carbon black, 30 parts. The specific implementation method is as follows:

[0138] The SR raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, guanidine accelerators, PBO-3mm and white carbon black are added in sequence. The temperature of the rubber compound is controlled at about 60°C, and thinned 10 times. 2,5-dimethyl-2,5-bis-(tert-butylperoxy)hexane is added, and the rubber compound is evenly mixed and thinned 10 times. After being formed into sheets, the sheets are adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 160°C for 40 minutes with a vulcanization pressure of 15 MPa to prepare the ablation-resistant SR thermal insulation material.

[0139] Embodiment 31

[0140] EPDM rubber, 100 parts; benzoyl peroxide, 4 parts; PBO-3mm, 20 parts; white carbon black, 35 parts; tributyl phosphate, 6 parts. The specific implementation method is as follows:

[0141] The EPDM raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, PBO-3mm, white carbon black and tributyl phosphate are added in sequence. The temperature of the rubber compound is controlled at about 50°C, and thinned 10 times. Benzoyl peroxide is added, and the rubber compound is evenly mixed and thinned 10 times. After being sheeted, it is adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 160°C for 55 minutes with a vulcanization pressure of 15 MPa to prepare the ablation-resistant EPDM thermal insulation material.

[0142] Embodiment 32

[0143] NBR, 100 parts; sulfur, 4 parts; PBO-pulp, 20 parts; carbon black, 25 parts; boron phenolic resin TH-390, 5 parts; siloxane, 5 parts. The specific implementation method is as follows:

[0144] The NBR raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, boron phenolic resin TH-390, PBO-pulp, carbon black and siloxane are added in sequence. The temperature of the rubber compound is controlled at about 60°C, and thinned 10 times. Sulphur is added, and the rubber compound is evenly mixed and thinned 10 times. After being sheeted, it is adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 150°C for 40 minutes with a vulcanization pressure of 15 MPa to prepare the ablation-resistant NBR thermal insulation material.

[0145] Embodiment 33

[0146] EPDM rubber, 100 parts; thiazole accelerator, 6 parts; sulfur / dicumyl peroxide, 4.5 parts; PBO-9mm, 15 parts; white carbon black, 40 parts; silazane, 5 parts. The specific implementation method is as follows:

[0147] The EPDM raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, thiazole accelerators, PBO-9mm, white carbon black and silazane are added in sequence. The temperature of the rubber compound is controlled at about 60°C, and thinned 10 times. Sulfur / diisopropylbenzene peroxide is added, and the rubber compound is evenly mixed and thinned 10 times. After being sheeted, it is adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 140°C for 70 minutes with a vulcanization pressure of 15 MPa to prepare the ablation-resistant EPDM thermal insulation material.

[0148] Embodiment 34

[0149] NBR, 100 parts; thiazole accelerator, 8 parts; dicumyl peroxide, 3 parts; PBO-3mm, 25 parts; white carbon black, 35 parts; paraffin oil, 5 parts; silazane, 10 parts. The specific implementation method is as follows:

[0150] The NBR raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, thiazole accelerators, PBO-3mm, white carbon black, paraffin oil and silazane are added in sequence. The temperature of the rubber compound is controlled at about 60°C, and thinned 10 times. Diisopropylbenzene peroxide is added, and the rubber compound is evenly mixed and thinned 10 times. After being discharged from the sheet, it is adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 160°C for 70 minutes with a vulcanization pressure of 15 MPa to prepare the ablation-resistant NBR thermal insulation material.

[0151] Embodiment 35

[0152] EPDM rubber, 100 parts; dicumyl peroxide, 1 part; PBO-3mm, 8 parts; white carbon black, 20 parts; dioctyl sebacate, 10 parts; silazane, 10 parts. The specific implementation method is as follows:

[0153] The EPDM raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, PBO-3mm, white carbon black, dioctyl sebacate and silazane are added in sequence. The temperature of the rubber compound is controlled at about 60°C, and thinned 10 times. Diisopropyl peroxide is added, and the rubber compound is evenly mixed and thinned 10 times. After being formed into sheets, the sheets are adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 150°C for 60 minutes with a vulcanization pressure of 15 MPa to prepare the ablation-resistant EPDM thermal insulation material.

[0154] Embodiment 36

[0155] SR rubber, 100 parts; dicumyl peroxide, 2 parts; PBO-pulp, 15 parts; white carbon black, 20 parts; siloxane, 5 parts. The specific implementation method is as follows:

[0156] The SR raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, PBO pulp, white carbon black and siloxane are added in sequence. The temperature of the rubber compound is controlled at about 60°C, and thinned 10 times. Diisopropylbenzene peroxide is added, and the rubber compound is evenly mixed and thinned 10 times before being produced into sheets. After adjusting at room temperature for 24 hours, hot-press vulcanization is performed at 140°C for 50 minutes and the vulcanization pressure is 10 MPa to prepare the ablation-resistant SR thermal insulation material.

[0157] Embodiment 37

[0158] EPDM rubber, 100 parts; sulfur / dicumyl peroxide, 2.5 parts; PBO-pulp, 20 parts; white carbon black, 25 parts; ammonium polyphosphate, 20 parts; siloxane, 15 parts. The specific implementation method is as follows:

[0159] The EPDM raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, ammonium polyphosphate, PBO-pulp, white carbon black and siloxane are added in sequence. The temperature of the rubber compound is controlled at about 60°C, and thinned 10 times. Sulfur / diisopropylbenzene peroxide is added, and the mixture is evenly mixed and thinned 10 times. After being discharged from the sheet, it is adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 160°C for 50 minutes with a vulcanization pressure of 15 MPa to prepare the ablation-resistant EPDM thermal insulation material.

[0160] Embodiment 38

[0161] EPDM rubber, 100 parts; thiuram accelerator, 12 parts; dicumyl peroxide, 1 part; PBO-3mm, 25 parts; white carbon black, 35 parts; aminophenol-formaldehyde resin, 15 parts; siloxane, 20 parts. The specific implementation method is as follows:

[0162] The EPDM raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, thiuram accelerator, aminophenol-formaldehyde resin, PBO-3mm, white carbon black and siloxane are added in sequence. The temperature of the rubber compound is controlled at about 60°C, and thinned 10 times. Diisopropylbenzene peroxide is added, and the rubber compound is evenly mixed and thinned 10 times. After being sheeted, it is adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 140°C for 70 minutes with a vulcanization pressure of 15 MPa to prepare the ablation-resistant EPDM thermal insulation material.

[0163] Embodiment 39

[0164] EPDM rubber, 100 parts; sulfonamide accelerator, 15 parts; sulfur / diisopropylbenzene peroxide, 5 parts; PBO-3mm, 20 parts; white carbon black, 35 parts; paraffin oil, 7 parts. The specific implementation method is as follows:

[0165] The EPDM raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, sulfonamide accelerators, PBO-3mm, white carbon black and paraffin oil are added in sequence. The temperature of the rubber compound is controlled at about 70°C, and thinned 20 times. Sulfur / diisopropylbenzene peroxide is added, and the rubber compound is evenly mixed and thinned 20 times. After being sheeted, it is adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 160°C for 55 minutes with a vulcanization pressure of 10 MPa to prepare the ablation-resistant EPDM thermal insulation material.

[0166] Comparative Example 1

[0167] EPDM rubber, 100 parts; thiazole accelerator, 12 parts; sulfur, 2 parts; PF, 12 parts; white carbon black, 25 parts; magnesium hydroxide, 10 parts. The specific implementation method is as follows:

[0168] The EPDM raw rubber is plasticized on an open mixing mill for 3 minutes. After being evenly mixed, thiazole accelerators, magnesium hydroxide, PF and white carbon black are added in sequence. The temperature of the rubber compound is controlled at about 60°C, and thinned 15 times. Sulphur is added, and the rubber compound is evenly mixed and thinned 15 times. After being sheeted, it is adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 150°C for 60 minutes with a vulcanization pressure of 10 MPa to prepare the ablation-resistant EPDM thermal insulation material.

[0169] Comparative Example 2

[0170] EPDM rubber, 100 parts; thiazole accelerator, 9 parts; dicumyl peroxide, 4 parts; PI, 15 parts; white carbon black, 30 parts; ammonium polyphosphate, 15 parts. The specific implementation method is as follows:

[0171] The EPDM raw rubber is plasticized on an open mixing mill for 3 minutes. After being evenly mixed, thiazole accelerators, ammonium polyphosphate, PI and white carbon black are added in sequence. The temperature of the rubber compound is controlled at about 60°C, and thinned through 15 times. Diisopropylbenzene peroxide is added, and the rubber compound is evenly mixed and thinned through 15 times. After being discharged from the sheet, it is adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 160°C for 60 minutes with a vulcanization pressure of 10 MPa to prepare the ablation-resistant EPDM thermal insulation material.

[0172] Comparative Example 3

[0173] SR rubber, 100 parts; 2,5-dimethyl-2,5-bis-(tert-butylperoxy)hexane, 2 parts; KF, 15 parts; carbon black, 30 parts; boron phenolic resin TH-390, 20 parts. The specific implementation method is as follows:

[0174] The SR raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, boron phenolic resin TH-390, KF and carbon black are added in sequence. The temperature of the rubber compound is controlled at about 60°C, and thinned 10 times. 2,5-dimethyl-2,5-bis-(tert-butylperoxy)hexane is added, and the mixture is evenly mixed and thinned 10 times. After the mixture is formed into sheets, it is adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 150°C for 50 minutes with a vulcanization pressure of 10 MPa to prepare the ablation-resistant SR thermal insulation material.

[0175] Comparative Example 4

[0176] EPDM rubber, 100 parts; thiuram accelerator, 5 parts; dicumyl peroxide, 5 parts; KF, 18 parts; white carbon black, 35 parts; aluminum hydroxide, 20 parts. The specific implementation method is as follows:

[0177] The EPDM raw rubber was plasticized on an open mixing mill for 3 minutes. After being evenly mixed, thiuram accelerators, aluminum hydroxide, KF and white carbon black were added in sequence. The temperature of the rubber compound was controlled at about 60°C, and thinned through 15 times. Diisopropylbenzene peroxide was added, and the rubber compound was evenly mixed and thinned through 15 times. After being discharged from the sheet, it was adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 160°C for 55 minutes with a vulcanization pressure of 10 MPa to prepare the ablation-resistant EPDM thermal insulation material.

[0178] Comparative Example 5

[0179] NBR rubber, 100 parts; thiuram accelerator, 5 parts; benzoyl peroxide, 2 parts; PI-pulp, 20 parts; white carbon black, 35 parts; aminophenol-formaldehyde resin, 10 parts. The specific implementation method is as follows:

[0180] The NBR raw rubber is plasticized on an open mixing mill for 5 minutes. After being evenly mixed, thiuram accelerator, aminophenol-formaldehyde resin, PI-pulp and white carbon black are added in sequence. The temperature of the rubber compound is controlled at about 60°C, and thinned 10 times. Benzoyl peroxide is added, and the rubber compound is evenly mixed and thinned 10 times. After being sheeted, it is adjusted at room temperature for 24 hours, and hot-pressed and vulcanized at 160°C for 50 minutes with a vulcanization pressure of 10 MPa to prepare the ablation-resistant NBR thermal insulation material.

[0181] Comparative Example 6

[0182] EPDM rubber 90 parts, PZ rubber, 10 parts; thiazole agent, 5 parts; dicumyl peroxide, 2 parts; PBO-3mm, 15 parts; white carbon black, 35 parts; aminophenol-formaldehyde resin, 10 parts. The specific implementation method is as follows:

[0183] The EPDM / PZ raw rubber was plasticized on an open mixing mill for 5 minutes. After being evenly mixed, thiazole accelerators, aminophenol-formaldehyde resin, PBO-3mm and white carbon black were added in sequence. The temperature of the rubber compound was controlled at about 60°C, and thinned 10 times. Diisopropylbenzene peroxide was added, and the rubber compound was evenly mixed and thinned 10 times before being produced into sheets. After adjusting at room temperature for 24 hours, the rubber compound was hot-pressed and vulcanized at 160°C for 60 minutes with a vulcanization pressure of 15 MPa to prepare the ablation-resistant EPDM / PZ thermal insulation material.

[0184] In the above embodiments and comparative examples, the tensile strength and elongation at break of the thermal insulation material are measured according to "GB / T 528-2009 Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber"; the linear ablation rate is measured according to "GJB 323A-96 Ablation test method for ablative materials"; the density is measured according to "GB / T 533-2008 Determination of density of vulcanized rubber or thermoplastic rubber"; and the bonding strength with metal is measured according to "GB / T 13936-2014 Determination method for tensile shear strength of bonding between vulcanized rubber and metal".

[0185] Table 1 Comparison of thermal insulation material properties between examples and comparative examples

[0186]

[0187]

[0188] It can be concluded from the mechanical property data in Table 1 that the thermal insulation material and the preparation method thereof in the embodiment can maintain good mechanical properties even when the fiber is overfilled, that is, the mechanical properties in the parallel calendering direction and the perpendicular calendering direction are basically the same. In addition, the density of the thermal insulation material in the embodiment is relatively small, which effectively reduces the mass of the thermal insulation material, thereby reducing the negative mass of the engine and ultimately improving the range of the engine.

[0189] Example 8 and Comparative Examples 1, 2, and 4 describe the effect of fibers on material properties. Figure 1 The surfaces of PF, PI and KF fibers are relatively smooth, while the surface roughness of PBO fiber is higher than that of the other three fibers. Figure 3 As can be seen from the PF diagram, the tensile section of the EPDM / PF material shows a large number of PF fiber stubs. From the fiber pull-out holes, it can be seen that the fibers are not obviously pulled, and there is no EPDM matrix attached to the fiber surface, indicating that the interface bonding force between the PF fiber and the matrix is ​​weak, and it cannot effectively play a bearing role, and it is difficult to exert the high performance of the fiber. This is related to the inherent properties of the PF fiber itself. Due to the high brittleness of the PF fiber, the PF fiber is prone to breakage during the processing of the insulation material, and it is difficult to maintain the original shape. The ability to serve as a carbon layer skeleton material is weakened, resulting in a low carbon layer strength and an increased ablation rate. As can be seen from the PI diagram, the PI fiber in the EPDM / PI tensile section is obviously pulled. Due to the strong flexibility of the PI fiber, it is not easy to be damaged during the processing and maintains its original shape. However, there is no EPDM matrix attached to the surface of the pulled-out fiber, indicating that the interface bonding force between the PI fiber and the EPDM matrix is ​​weak. The KF fiber is obviously pulled at the cross section, and the layered EPDM matrix film is attached to the fiber surface, indicating that the KF fiber has a good interface force with the EPDM matrix, but the KF fiber agglomeration phenomenon appears in the EPDM / KF cross section, that is, there is no rubber matrix here, and the fibers are entangled and gathered together. When the material is stretched by external force, stress concentration occurs here, resulting in material damage, which is consistent with the change in the mechanical properties of EPDM / KF. It can be seen from the PBO figure that the PBO fiber is obviously pulled, and the fiber is pulled into a curved and thin state. The overall state is relatively messy, and it is obviously subjected to a certain force. There is an EPDM matrix film attached to the fiber surface, indicating that the PBO fiber has a strong interface bonding force with the EPDM matrix, which is conducive to the transmission of stress, giving full play to the high performance of the fiber, effectively enhancing the insulation material, and meeting the working conditions of the rocket engine.

[0190] Example 17 and Example 9, Example 7 and Example 10, Example 39 and Example 14 respectively describe the effects of PBO fiber modification on the properties of NBR, SR, and EPDM insulation materials. Taking EPDM / PBO as an example, the microscopic morphology of the cross section of the tensile specimen before and after modification and the dispersion of the fiber in the material matrix are shown in FIG. Figure 4 As shown. Figure 4 It can be seen that the fibers are pulled at the cross section, which indicates that the fibers effectively play a bearing role when the material is subjected to external forces. After the fibers are treated, it is obvious that the pores left by the pulled out fibers and the fibers that are not pulled out and remain in the matrix are evenly distributed on the cross-section surface. At the same time, it can be seen from the microscope image that after the modification, the fibers are more evenly dispersed in the matrix, avoiding the stress concentration problem caused by uneven dispersion, which is beneficial for the material to withstand greater external forces and improve the mechanical properties of the material. In addition, the alkoxy group at one end of the silane coupling agent is hydrolyzed to form a silanol group, which is oriented on the fiber surface, while the organic group at the other end of the coupling agent is oriented on the surface of the rubber material, participating in the cross-linking and curing reaction, and finally building a bridge between the fiber and the rubber matrix, improving the interfacial bonding between the fiber and the rubber matrix, making the material more dense and firm, and the fiber reinforcement effect is obvious.

[0191] It can be seen from the microscopic morphology of the carbon layer surface and cross section after ablation of the sample in Example 3 that PBO fibers can promote the connection of carbon residues in the insulation material matrix and form a dense and strong carbonized layer. The fibers serve as an embedded skeleton of the carbonized matrix to strengthen the carbon layer, prevent the carbon layer from stratification and peeling, and effectively improve the ability to resist erosion by high-speed heat flow. In addition, the high thermal stability of the fibers is conducive to maintaining the original structure and morphology and strengthening the carbon layer.

[0192] The present invention successfully prepares a solid rocket engine inner insulation layer material with high ablation resistance, low density, excellent metal bonding performance and mechanical properties through the optimization and modification technology of PBO fibers and the high performance of a comprehensive formula of ablation-resistant resins, flame retardant systems, plasticizers, etc.

[0193] The above embodiments are further detailed descriptions of the present invention, but not limitations of the present invention. For ordinary technicians in the relevant field, various equivalent substitutions or improvements can be made to the technical solutions and implementation methods of the present invention. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A PBO fiber-filled rubber-type ablation-resistant thermal insulation material, characterized in that: The invention comprises the following components in parts by weight: rubber, 100 parts; accelerator, 0 to 20 parts; vulcanizer, 0.5 to 10 parts; fiber, 0 to 80 parts and not 0; reinforcing agent, 0 to 50 parts; plasticizer, 0 to 20 parts; flame retardant, 0 to 30 parts; ablation-resistant filler, 0 to 30 parts; and porcelain-forming filler, 0 to 20 parts.

2. A PBO fiber-filled rubber-type ablation-resistant thermal insulation material according to claim 1, characterized in that: The invention comprises the following components in parts by weight: rubber, 100 parts; accelerator, 0 to 15 parts; vulcanizer, 0.5 to 5 parts; fiber, 0 to 30 parts and not 0; Reinforcing agent, 0-30 parts; plasticizer, 0-20 parts; flame retardant, 0-20 parts; ablation-resistant filler, 0-20 parts; porcelain-forming filler, 0-20 parts.

3. A PBO fiber-filled rubber-type ablation-resistant thermal insulation material according to claim 1 or 2, characterized in that: The rubber is one or more of natural rubber, butadiene rubber, styrene-butadiene rubber, chloroprene rubber, nitrile rubber, ethylene-propylene rubber, graft-modified ethylene-propylene rubber, EPDM rubber, polyurethane elastomer, silicone rubber, fluororubber, polyphosphazene elastomer, chlorosulfonated polyethylene rubber, polysulfide rubber, and polyisoprene rubber; The accelerator is one or more of thiazoles, sulfenamides, thiurams, dithiocarbamates, guanidines and xanthates; The vulcanizing agent is one or more of sulfur, organic peroxide, and metal oxide; The reinforcing agent is one or more of carbon black, white carbon black, silicate, calcium carbonate, montmorillonite, and zinc oxide; The plasticizer is one or more of liquid ethylene-propylene rubber, liquid hydroxyl-terminated polybutadiene, aliphatic hydrocarbons, cycloalkanes, aromatic hydrocarbon process oils, phthalates, fatty dibasic acid esters, fatty acids, phosphates, polyesters, epoxies, and chlorine-containing ones; The flame retardant is one or more of inorganic, organic phosphorus and organic halogen; The ablation-resistant filler is one or more of phenolic resin such as boron phenolic resin or barium phenolic resin, clay, montmorillonite, phenolic hollow microspheres, silicon dioxide or glass microspheres, and cork; The ceramic filler is one or more of silazane and siloxane; The fiber is one or more of pulp, short-cut fiber, long fiber and fiber cloth containing poly(p-phenylene benzobisoxazole) (PBO) structure.

4. A PBO fiber-filled rubber-type ablation-resistant thermal insulation material according to claim 1 or 2, characterized in that: The fiber includes one or more of carbon fiber, glass fiber, ceramic fiber, aramid fiber, aramid pulp, aramid fiber, aramid pulp, phenolic fiber, polyimide fiber and asbestos fiber.

5. A PBO fiber-filled rubber-type ablation-resistant thermal insulation material according to claim 1 or 2, characterized in that: The fiber can be surface pretreated or surface untreated; Fiber pretreatment methods include dispersion treatment and / or chemical modification; The fiber pretreatment preparation process includes the following: (1) Fiber dispersion treatment: break up the fibers to improve their uniform distribution in the matrix. (2) Fiber chemical modification: After removing impurities from the surface of PBO fibers (which can be scattered or not), the fibers are dried and then treated with chemical modifiers or plasma etching to increase the number of polar functional groups on the fiber surface and improve the surface free energy of the fibers, thereby enhancing the interfacial bonding between the fibers and the matrix and giving the flexible thermal insulation material excellent mechanical properties and ablation resistance. The coupling agent is one or more of hydrocarbon silanes.

6. The method according to claim 5, characterized in that The chemical modifier is a mixture of a coupling agent, anhydrous ethanol and distilled water, wherein the coupling agent concentration is 0-40% and is not 0.

7. A method for preparing a PBO fiber-filled rubber-type ablation-resistant thermal insulation material according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step S1, weighing according to the formula, firstly plasticating the raw rubber on an open mixing mill; Step S2, after being evenly mixed, add accelerator, flame retardant, ablation-resistant filler, fiber, reinforcing agent, plasticizer, and porcelain-forming filler in sequence, and pass through several times; Step S3, finally adding the vulcanizing agent, mixing evenly and then thinning for several times, producing a sheet for standby use, and vulcanizing and molding by a flat vulcanizing machine to prepare a PBO fiber-filled ablation-resistant flexible insulation material.

8. The method according to claim 7, characterized in that Before vulcanization, the mixed rubber material should be conditioned at room temperature for not less than 12 hours.

9. The method according to claim 7, characterized in that The vulcanization conditions are as follows: a vulcanization temperature of 130°C to 170°C, a vulcanization time of 30min to 100min, and a vulcanization pressure of 5MPa to 30MPa.

10. Use of the PBO fiber-filled rubber-type ablation-resistant insulation material according to any one of claims 1 to 6 for solid rocket insulation layer materials.

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