Solid engine heat-light curing heat insulation-lining material and preparation method thereof

Abstract

The invention discloses a solid engine thermo-photo-curing heat insulation-lining material and a preparation method thereof.The thermo-photo-curing heat insulation-lining material is prepared by taking telechelic epoxy acrylate phosphate resin as a base material and adding auxiliaries such as fibers, ablation-resistant resin and a plasticizer, a blade coating forming process is adopted, and the thermal-photo-curing heat insulation-lining material is obtained. And the slurry is formed on the inner wall of a solid engine shell, ultraviolet irradiation preliminary curing is carried out, and after solid propellant charging is completed, the material and the propellant are subjected to synchronous thermocuring forming. The problems of long semi-curing period, unmeasurable curing degree, low bonding strength margin and the like of the traditional hydroxyl-terminated polybutadiene lining can be solved; the thermal / photo-curing heat insulation / lining material is used as an engine thermal protection material, has the advantages of ablation resistance, high propellant bonding strength and the like, can solve the problems of interface debonding and the like caused by large difference between an existing rubber-based heat insulation layer and a hydroxyl-terminated polybutadiene lining resin system, and realizes high-efficiency, high-quality and batch production of engine heat insulation and liners.

Description

Technical Field

[0001] The invention belongs to the technical field of solid engine thermal insulation materials and propellant charges, and in particular relates to a solid engine thermal-photocuring thermal insulation-lining material and a preparation method thereof. Background Art

[0002] Solid rocket engines are power units for missiles, rockets and other weapons and equipment. They have the advantages of high mobility, low cost, easy maintenance and simple manufacturing process. They are widely used in military, aerospace and national economic construction. The existing solid engine insulation layer mainly uses nitrile and EPDM rubber-based insulation materials. The engine thermal protection layer is made by hand or vacuum patch process. The lining layer is mainly made of terminal hydroxyl polybutadiene as the matrix resin, and is prepared by adding reinforcing agents, plasticizers, curing agents and other additives. It is made by solvent dilution or scraping molding process, and is pre-cured at 50℃-70℃ for 3h-6h. After reaching "semi-curing", the propellant is loaded. Due to the differences in the rubber-based insulation layer, butyl hydroxy lining layer and propellant matrix resin system, the mechanical, compatibility and chemical properties of the materials on both sides of the insulation / lining layer / propellant interface are quite different, which is easy to produce bulging type, layer gap type, close-fitting type and spot type bonding defects, making the insulation / lining layer / propellant interface a weak link, and it is easy to have quality problems such as interface debonding failure under external complex load conditions.

[0003] Corresponding research has been carried out. For example, Chinese patent application No. CN202111508707.X discloses the independent synthesis and preparation of telechelic epoxy acrylate phosphate resin, and designs and develops a formula suitable for solid engine insulation / lining integrated material based on the performance of heat / photocuring ablation-resistant resin. The heat / photocuring characteristics of telechelic epoxy acrylate phosphate resin are used to solve the problems of long semi-curing cycle and unpredictable degree of curing of lining materials, while having ablation resistance and mechanical properties, meeting the performance requirements of the engine insulation layer, and solving quality problems such as insulation / lining / propellant interface bonding.

[0004] For example, Chinese patent application number CN202210871357.1 discloses a thermal insulation / lining material formula and preparation method based on spray molding technology. Chinese patent application number CN201610672693.8 reports a preparation method of a room temperature photocurable polyurethane acrylate ionomer emulsion thermal insulation material. Deng Jianru et al. reported a study on the synthesis and application of a photocurable resin for a solid rocket engine lining. The photocurable lining material has good bonding strength with the thermal insulation layer and can effectively hinder the migration of small molecule plasticizers.

[0005] However, the traditional HTPB lining has problems such as long semi-curing cycle and unpredictable degree of curing. It is necessary to develop a new technical route for the production of solid engine insulation / lining materials. Summary of the invention

[0006] In order to solve the problems of the long semi-curing cycle of the traditional hydroxybutyl liner and the unmeasurable degree of curing, the present invention provides a solid engine heat-light-cured insulation-liner material and a preparation method thereof. The present invention has developed a technical route different from the methods and technical routes adopted by the insulation / liner materials, light-cured insulation materials and light-cured liner materials reported in the existing public literature. It is a new technical route for the production of solid engine insulation / liner materials. From the material formula design and molding process, the insulation / liner integrated molding is realized, and the bonding interface strength of the solid engine insulation layer / liner / propellant is improved. On the one hand, it can solve the problems of the long semi-curing cycle of the traditional hydroxybutyl liner, the unmeasurable degree of curing and the low bonding strength margin; on the other hand, the heat / light-cured insulation / liner material as an engine thermal protection material has the advantages of ablation resistance and high propellant bonding strength, which can solve the problems of interface debonding caused by the large difference between the existing rubber-based insulation layer and the hydroxybutyl liner resin system, realize the high efficiency, high quality and batch production of engine insulation and liner, and provide a new solution for the manufacture of solid engine insulation coating materials.

[0007] Technical principle of the present invention:

[0008] The present invention discloses a solid engine heat-light-curing insulation-lining material. The heat / light-curing insulation / lining material is prepared by using a telechelic epoxy acrylic phosphate resin as a matrix material, adding fibers, ablation-resistant resins, plasticizers and other additives, and using a scraper coating process to form the slurry on the inner wall of the solid engine casing, which is initially cured by ultraviolet light irradiation. After the solid propellant is loaded, the material is thermally cured synchronously with the propellant.

[0009] The purpose of the present invention is achieved through the following technical solutions:

[0010] A solid engine heat-light-cured insulation-lining material, made of the following components by mass percentage: 40%-60% of telechelic epoxy acrylic phosphate resin, 10%-20% of fiber filler, 5%-10% of adhesive, 5%-15% of ablation-resistant resin, 8%-12% of reinforcing agent, 2%-5% of active diluent monomer, 2%-3% of photoinitiator and 3%-5% of plasticizer;

[0011] The molecular weight of the telechelic epoxy acrylate phosphate resin is one or more of 3000, 5000 and 7000;

[0012] The fiber filler is selected from one or two of basalt fiber, high silica fiber and alumina fiber, and the mixing ratio of the two fibers is 1:1-1:5.

[0013] The adhesive is selected from one or two of type III hydroxyl-terminated polybutadiene and epoxy resin, and multiple adhesives can be mixed in any proportion;

[0014] The ablation-resistant resin is selected from one or two of phenolic resin, polyimide resin and furfural resin, and the two resins are mixed in a ratio of 1:1-1:3;

[0015] The reinforcing agent is selected from one or both of fumed silica and precipitated silica, and the mixture can be in any proportion;

[0016] The active diluent monomer is selected from one or both of 6-hexanediol diacrylate and epoxy acrylate, and the mixture can be in any proportion;

[0017] The photoinitiator is selected from 2-hydroxy-2-methyl-1-phenyl-1-propanone;

[0018] The plasticizer is selected from one of dibutyl phthalate, dioctyl phthalate and dioctyl sebacate.

[0019] Furthermore, the fiber filler has a length of 1 mm to 3 mm, and the fiber filler is pre-coated with type III terminal hydroxyl polybutadiene or epoxy resin for surface treatment.

[0020] The method for preparing the above-mentioned solid engine heat-light-cured insulation-lining material comprises the following steps:

[0021] S1: Prepare various components of the solid engine heat / light-curing insulation / lining material, add various additives of the solid engine heat / light-curing insulation / lining material to the telechelic epoxy acrylate phosphate resin according to mass percentage, and mix them evenly with a pneumatic stirring paddle to obtain a solid engine heat / light-curing insulation / lining slurry;

[0022] S2: placing the uniformly mixed solid engine heat / light-cured insulation / lining slurry obtained in S1 into the engine casing, the casing is kept rotating at a speed of 50-100 rpm, and a silicone rubber sheet is used for uniform scraping and molding;

[0023] S3: Selecting a UV light source with a wavelength of 200 μm-350 μm, irradiating the solid engine heat / light-cured insulation / lining slurry obtained in step S2, and irradiating for 5 min-20 min;

[0024] S4: The solid engine heat / light-cured insulation / lining slurry that has been pre-cured by ultraviolet light in S3 is charged with hydroxybutane propellant. The solid engine heat / light-cured insulation / lining and propellant curing temperature is 50°C-70°C, and the curing time is 3d-7d, to obtain a solid engine heat-light-cured insulation-lining material.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] 1. The solid engine heat-photocuring insulation-lining material described in the present invention has a formula that combines the characteristics of heat / photocuring matrix resin and is designed and developed to be suitable for the performance requirements of the insulation layer and the lining. It has properties such as ablation resistance, mechanics, bonding and curing, and can solve the problems of low interface bonding strength, bulging and weak adhesion between traditional rubber-based insulation materials and hydroxybutane linings due to different resin systems.

[0027] 2. The preparation method of a solid engine heat-photocuring insulation-lining material described in the present invention realizes initial pre-curing through ultraviolet light curing to ensure that the initial strength of the insulation / lining material meets the requirements of the propellant charge vacuum evacuation process, while retaining active groups such as isocyanate groups or epoxy groups, reacting with active hydrogen or isocyanate groups in the hydroxybutane propellant to achieve "chemical bonding" at the bonding interface, thereby ensuring the solid engine interface bonding strength and greatly reducing the cycle of engine insulation production and lining coating.

[0028] 3. The existing hydroxybutane lining needs to reach the "semi-cured" level in the charge coating process to meet the requirements of vacuum extraction and bonding performance. Due to the limitations of detection technology and environmental factors, it is currently impossible to accurately test the semi-cured level, and it is difficult to determine the semi-cured level. The solid engine heat-photocuring insulation-lining material described in the present invention adjusts the molecular weight and addition amount of the photocuring resin and the photocuring parameters to control the curing and cross-linking degree of the photocuring resin, thereby achieving quantitative and constant strength pre-curing of the insulation / lining material and achieving precise semi-curing molding of the heat / photocuring lining material. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the sample after heat / photocuring insulation / liner oxyacetylene ablation of the solid motor charge in Experimental Example 1 of the present invention. DETAILED DESCRIPTION

[0030] The present invention is further described in detail below by way of examples, but these examples should not be considered as limiting the present invention.

[0031] A solid engine heat-light-cured insulation-lining material, made of the following components in percentage by mass:

[0032] Table 1 shows the formula composition ratio of the heat / light curing liner material in different implementation cases:

[0033]

[0034] Embodiment 1:

[0035] A method for preparing a solid engine heat-light-cured insulation-lining material comprises the following steps:

[0036] According to the formula ratio of heat / light curing insulation / lining, various additives are added to the telechelic epoxy acrylate phosphate resin, and the materials are mixed with a pneumatic stirring paddle. The evenly mixed slurry is placed on the inner wall of the engine casing, and the casing is rotated at a speed of 70 rpm. A silicone rubber plate is used for uniform scraping and molding. A 200 μm ultraviolet light source wavelength is selected for irradiation for 20 minutes. After pre-curing is completed, the propellant is loaded. The curing temperature of the insulation / lining material and the propellant is 50°C and the curing time is 7 days.

[0037] Figure 1 This is a schematic diagram of the sample after thermal / photocuring insulation / liner oxyacetylene ablation of the solid motor propellant in Experimental Example 1.

[0038] Embodiment 2:

[0039] A method for preparing a solid engine heat-light-cured insulation-lining material comprises the following steps:

[0040] According to the formula ratio of heat / light-curing insulation / lining, each additive is added to the telechelic epoxy acrylate phosphate resin, and the materials are mixed with a pneumatic stirring paddle. The evenly mixed slurry is placed on the inner wall of the engine casing, and the casing is kept rotating at 100 rpm. A silicone rubber plate is used for uniform scraping and molding. A 350 μm ultraviolet light source wavelength is selected for irradiation for 5 minutes. After pre-curing is completed, the propellant is loaded. The curing temperature of the insulation / lining material and the propellant is 70°C and the curing time is 3 days.

[0041] Embodiment 3:

[0042] A method for preparing a solid engine heat-light-cured insulation-lining material comprises the following steps:

[0043] According to the formula ratio of heat / light curing insulation / lining, each additive is added to the telechelic epoxy acrylate phosphate resin, and the materials are mixed with a pneumatic stirring paddle. The evenly mixed slurry is placed on the inner wall of the engine casing, and the casing is kept rotating at 50 rpm. A silicone rubber plate is used for uniform scraping and molding. A 300 μm ultraviolet light source wavelength is selected for irradiation for 10 minutes. After pre-curing is completed, the propellant is loaded. The curing temperature of the insulation / lining material and the propellant is 60°C and the curing time is 5 days.

[0044] Embodiment 4:

[0045] A method for preparing a solid engine heat-light-cured insulation-lining material comprises the following steps:

[0046] According to the formula ratio of heat / light curing insulation / lining, each additive is added to the telechelic epoxy acrylate phosphate resin, and the materials are mixed with a pneumatic stirring paddle. The evenly mixed slurry is placed on the inner wall of the engine casing, and the casing is kept rotating at 80 rpm. A silicone rubber plate is used for uniform scraping and molding. A 250 μm ultraviolet light source wavelength is selected for irradiation for 16 minutes. After pre-curing is completed, the propellant is loaded. The curing temperature of the insulation / lining material and the propellant is 70°C and the curing time is 3 days.

[0047] Comparative Example 1 (EPDM insulation material):

[0048] Silica reinforcement, phenolic resin, fiber filler, plasticizer, sulfur and vulcanizing agent were added to EPDM rubber, and mixed and blended using internal mixer and open mixer. The vulcanized samples were subjected to ablation, mechanical and steel interface bonding strength tests.

[0049] Comparative Example 2 (HTPB lining material):

[0050] A crosslinking agent, a curing agent, a plasticizer, a solid phase filler, etc. are added to the terminal hydroxy polybutadiene adhesive to prepare a hydroxybutadiene lining material. After the sample is cured, ablation, mechanical and propellant interface bonding strength tests are performed.

[0051] The performance test results of the solid engine heat-light-cured insulation-lining material of Example 1-4 and Comparative Example 1-2 are shown in Table 2:

[0052]

[0053] The results show that:

[0054] 1. By comparing Examples 1-4 with Comparative Example 1, it is shown that the heat-light-cured insulation-lining material of the present invention has good bonding properties with the propellant interface, the oxygen-acetylene line ablation rate is 0.16-0.24 mm / s (25 s), the tensile strength is 5.21-6.57 MPa, the elongation at break is 246-323%, the propellant interface bonding strength is 0.78-0.85 MPa, and the steel interface bonding strength is 3.09-3.42 MPa; there is no need for a traditional hydroxybutyl liner as the interface bonding layer between the propellant and the insulation material, and the performance is basically equivalent to that of the rubber insulation material.

[0055] 2. By comparing Examples 1-4 with Comparative Example 2, it is shown that the heat-light-cured insulation-lining material of the present invention has comparable propellant bonding properties to the hydroxybutane lining, and can be directly used as a bonding layer between the propellant and the insulation layer. At the same time, the heat-light-cured insulation-lining material has good ablation resistance and mechanical properties.

[0056] The above are only preferred implementations of the present invention. The protection scope of the present invention is not limited to the above embodiments. Various process schemes that are not substantially different from the concept of the present invention are within the protection scope of the present invention.

Claims

1. A solid engine heat-light-cured insulation-lining material, characterized in that: Made of the following components in percentage by mass: Telechelic epoxy acrylic phosphate resin 40%-60%, fiber filler 10%-20%, adhesive 5%-10%, ablation-resistant resin 5%-15%, reinforcing agent 8%-12%, active diluent monomer 2%-5%, photoinitiator 2%-3% and plasticizer 3%-5%; The molecular weight of the telechelic epoxy acrylate phosphate resin is one or more of 3000, 5000 and 7000; The fiber filler is selected from one or two of basalt fiber, high silica fiber and alumina fiber, and the mixing ratio of the two fibers is 1:1-1:

5. The adhesive is selected from one or two of type III hydroxyl-terminated polybutadiene and epoxy resin, and multiple adhesives can be mixed in any proportion; The ablation-resistant resin is selected from one or two of phenolic resin, polyimide resin and furfural resin, and the two resins are mixed in a ratio of 1:1-1:3; The reinforcing agent is selected from one or both of fumed silica and precipitated silica, and the mixture can be in any proportion; The active diluent monomer is selected from one or both of 6-hexanediol diacrylate and epoxy acrylate, and the mixture can be in any proportion; The photoinitiator is selected from 2-hydroxy-2-methyl-1-phenyl-1-propanone; The plasticizer is selected from one of dibutyl phthalate, dioctyl phthalate and dioctyl sebacate.

2. A solid engine heat-light-cured insulation-lining material according to claim 1, characterized in that: The fiber filler has a length of 1 mm to 3 mm, and the fiber filler is pre-coated with type III terminal hydroxyl polybutadiene or epoxy resin for surface treatment.

3. The method for preparing a solid engine heat-light-cured insulation-lining material according to claim 1 or 2, characterized in that: The following steps are involved: S1: Prepare various components of the solid engine heat / light-curing insulation / lining material, add various additives of the solid engine heat / light-curing insulation / lining material to the telechelic epoxy acrylate phosphate resin according to mass percentage, and mix them evenly with a pneumatic stirring paddle to obtain a solid engine heat / light-curing insulation / lining slurry; S2: placing the uniformly mixed solid engine heat / light-cured insulation / lining slurry obtained in S1 into the engine casing, the casing is kept rotating at a speed of 50-100 rpm, and a silicone rubber sheet is used for uniform scraping and molding; S3: Selecting a UV light source with a wavelength of 200 μm-350 μm, irradiating the solid engine heat / light-cured insulation / lining slurry obtained in step S2, and irradiating for 5 min-20 min; S4: The solid engine heat / light-cured insulation / lining slurry that has been pre-cured by ultraviolet light in S3 is charged with hydroxybutane propellant. The solid engine heat / light-cured insulation / lining and propellant curing temperature is 50°C-70°C, and the curing time is 3d-7d, to obtain a solid engine heat-light-cured insulation-lining material.

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