Lining material for azide propellant, preparation method and application

Abstract

The invention provides a lining for an azide propellant, a preparation method and application, and the lining is prepared from the following raw materials in parts by weight: 100-150 parts of hydroxyl-terminated polybutadiene, 40-100 parts of a filler, 1-3 parts of triethanolamine, 0.5-5 parts of a modifier, 2-5 parts of a bonding agent, 3-5 parts of a plasticizer, 10-40 parts of a curing agent, 0.6-1.2 parts of a catalyst and 1-3 parts of an alkynyl compound. The method comprises the following steps: dropwise adding a formula amount of alkynyl compound into a modifier, and fully stirring to obtain a mixed solution; under a stirring condition, dropwise adding the mixed solution into triethanolamine to obtain a modified chain extender; the preparation method comprises the following steps: mixing the hydroxyl-terminated polybutadiene, the filler, the modified chain extender, the plasticizer, the bonding agent, the curing agent and the catalyst according to a formula ratio. Alkynyl is introduced into a lining material in a chain extender modification mode, the defect caused by direct use of a small-molecule alkynyl compound is avoided, on the basis of isocyanate and hydroxyl curing reaction, 1, 3-dipolar cycloaddition reaction between alkynyl and azide is introduced, and a new cross-linked structure is generated.

Description

Technical Field

[0001] This invention belongs to the field of propellant liner technology, and relates to liner materials, specifically to a liner material for azide propellants, its preparation method, and its application. Background Technology

[0002] The liner, situated between the propellant and the insulation layer, is a crucial component of rocket engines. Its function is to bond the propellant and insulation, ensuring stable combustion and structural integrity of the propellant charge. With the development of weaponry, the performance of solid propellants directly impacts the combat effectiveness and survivability of missile weapons. Using glycidyl azide (GAP) as a high-energy binder can significantly improve the energy level of solid propellants. However, compared to traditional propellant binders, GAP binder molecules carry large-volume groups (-CH2N3), resulting in poor wettability between the GAP binder and the liner, weak chemical bonding, and prominent interfacial issues with the propellant charge. During engine operation, interfacial bonding failure can cause a surge in the propellant's burning surface, leading to engine malfunctions or even explosion and disintegration. Therefore, developing a dedicated liner for azide binders to improve the interfacial bonding performance of azide propellant charges is of great significance for the development of high-performance weaponry. Summary of the Invention

[0003] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a liner material for azide propellants, a preparation method and an application, so as to solve the technical problem of poor adhesion between the propellant and the insulation material when using GAP adhesive in the prior art.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0005] A method for preparing a liner material for azide propellants, wherein the method uses the following raw materials in parts by weight to prepare the liner material for azide propellants:

[0006] The mixture contains 100-150 parts of hydroxyl-terminated polybutadiene, 40-100 parts of filler, 1-3 parts of triethanolamine, 0.5-5 parts of modifier, 2-5 parts of bonding agent, 3-5 parts of plasticizer, 10-40 parts of curing agent, 0.6-1.2 parts of catalyst and 1-3 parts of alkynyl compound.

[0007] The method includes the following steps:

[0008] Step 1: Add the prescribed amount of alkynyl compound dropwise to the modifier and stir thoroughly to obtain a mixed solution;

[0009] Step 2: Under stirring conditions, the mixed solution is added dropwise to triethanolamine to obtain modified triethanolamine;

[0010] Step 3: Mix the raw materials in the following order: hydroxyl-terminated polybutadiene, filler, modified triethanolamine, plasticizer, bonding agent, curing agent, and catalyst.

[0011] The present invention also has the following technical features:

[0012] Specifically, by weight, the filler is composed of 20 to 50 parts of zinc oxide and 20 to 50 parts of silica.

[0013] Furthermore, the modifier is selected from any one or more of N,N'-carbonyldiimidazole, toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate.

[0014] Furthermore, the bonding agent is selected from any one or more of tri-1-(2-methylaziridine)phosphine oxide (MAPO), isophthaloyl(2-methylaziridine), and boron trifluoride triethanolamine complex.

[0015] Furthermore, the plasticizer is selected from any one of diisooctyl sebacate, dioctyl sebacate, diisooctyl phthalate, and dimethyl phthalate.

[0016] Furthermore, the curing agent is selected from any one of toluene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, and N-100, and the ratio of the molar number of -NCO groups to the sum of the molar numbers of -OH groups and -NH groups in the curing agent is 1.1 to 2.

[0017] Furthermore, the selected catalyst is chosen from one or two of triphenylbismuth, dibutyltin dilaurate, and stannous octoate.

[0018] Furthermore, the alkynyl compound is selected from any one of propargylamine, hepta-6-yn-1-amine, alkynyl-polyethylene glycol-amino, butynic acid, propargylic acid, methylbutynol, propargylol, ethynylcyclohexanol, and 3,7,11-trimethyldodecyn-3-ol.

[0019] This invention also protects a liner material for azide propellants, which is prepared by the above-described preparation method.

[0020] This invention also protects the application of the above-mentioned lining material for azide propellants in the insulating lining of solid rocket motor casings.

[0021] Compared with the prior art, the present invention has the following technical effects:

[0022] (1) The preparation method of the present invention introduces alkynyl groups into the liner material by modifying the chain extender, which avoids the end-capping defects caused by directly using small molecule alkynyl compounds and solves the problem that the quality consistency of the liner material cannot be controlled by directly adding small molecule alkynyl compounds; on the basis of isocyanate and hydroxyl curing reaction, a 1,3-dipolar cycloaddition reaction (Huisgen cycloaddition reaction) between alkynyl and azide groups is introduced to generate a new triazole ring crosslinking structure, thereby improving the degree of crosslinking between the two materials.

[0023] (2) The lining material provided by the present invention has strong adhesion strength to the azide propellant, which effectively solves the adhesion problem at the GAP propellant loading interface.

[0024] The specific content of the present invention will be further explained in detail below with reference to the embodiments. Attached Figure Description

[0025] Figure 1 This is the state of the sample from Example 1 after it was torn off;

[0026] Figure 2 This is the state of the comparative sample after it was torn apart.

[0027] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. Detailed Implementation

[0028] It should be noted that all raw materials used in this invention, unless otherwise specified, are all known in the prior art. For example, the bonding agents MAPO and T313 were purchased from Xi'an Hongda New Chemical Materials Co., Ltd.

[0029] The concept of this invention is to address the problem of poor adhesion between azide propellant and the liner by introducing alkynyl functional groups through a modified chain extender. During the co-curing process of the liner and propellant, cross-linking reactions occur simultaneously between the isocyanate groups and hydroxyl groups in the curing systems of the two materials, and between the alkynyl groups in the liner and the azide groups in the propellant, forming cross-linked structures such as carbamate and triazole rings. This enhances the degree of chemical bonding reaction between the two materials. By activating the reactive groups of the alkynyl compound to react with the functional groups of the chain extender, the alkynyl groups are grafted onto the chain extender, thus achieving chain extender modification treatment.

[0030] In this invention, the tear strength is tested according to the standard QJ 2038.1A—2004 "Test Method for Interfacial Adhesion Strength of Solid Rocket Engine Combustion Chamber Part 1: Tear-off Method of Rectangular Specimen"; the peel strength is tested according to the standard Q / AY 790-2017 "Determination of Interfacial Adhesion Strength of Free-Filling Solid Propellant Charges by Wheel Peel Method".

[0031] The performance tests in this invention use the following testing equipment:

[0032] Mechanical properties were tested using a QJ211B-20KV high and low temperature universal testing machine.

[0033] Following the above technical solutions, specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent modifications made based on the technical solutions of this application fall within the protection scope of the present invention.

[0034] Example 1

[0035] This embodiment provides a method for preparing a liner material for azide propellants. The method uses the following raw materials to prepare the liner material for azide propellants:

[0036] 100 parts of hydroxyl-terminated polybutadiene, 20 parts of zinc oxide, 30 parts of silica, 1.5 parts of triethanolamine, 5 parts of toluene diisocyanate (TDI, modifier), 2 parts of boron trifluoride triethanolamine complex (T313, bonding agent), 3 parts of dioctyl sebacate (plasticizer), 30 parts of isophorone diisocyanate (curing agent), 0.6 parts of dibutyltin disilicate (catalyst), and 1 part of acetylenol cyclohexanol (alkynyl compound).

[0037] The preparation method includes the following steps:

[0038] Step 1: Add the prescribed amount of methylbutyninol dropwise to TDI and stir thoroughly to obtain a mixed solution;

[0039] Step 2: Under stirring conditions, the mixed solution is added dropwise to triethanolamine to obtain the modified chain extender;

[0040] Step 3: Mix the raw materials in the following order: hydroxyl-terminated polybutadiene, filler, modified chain extender, plasticizer, bonding agent, curing agent and catalyst.

[0041] The azide propellant liner material prepared in this embodiment can be used as a heat insulation liner for a solid rocket motor casing. The usage steps are as follows:

[0042] Step S1: Sandblast the area to be coated on the surface of the insulation layer of the solid rocket motor casing;

[0043] Step S2: Pre-bake the heat insulation layer of the engine casing after sandblasting.

[0044] Step S3: Apply the azide propellant lining material evenly to the area to be coated on the surface of the insulation layer of the solid rocket motor casing;

[0045] Step S4: After the liner is in a semi-cured state, the propellant is poured in, and then the solid rocket motor casing coated with the liner material for azide propellant is placed in a constant temperature environment of 50-70°C to co-cur with the propellant.

[0046] The adhesion performance of the liner material prepared in this embodiment to the azide propellant was tested, and the results are shown in Table 1.

[0047] Referring to standard QJ2038.1, using the materials provided in this embodiment, rectangular specimens for the tear test were prepared using the same preparation method and curing conditions as the insulation liner of a solid rocket motor. After preparation, the specimens were mounted on a testing machine, and a tensile speed of 20 mm / min was applied at room temperature until the specimen broke. The load value was recorded, and the state of the specimen after tearing was as follows. Figure 1 As shown.

[0048] Example 2

[0049] This embodiment provides a method for preparing a liner material for azide propellants. The method uses the following raw materials to prepare the liner material for azide propellants:

[0050] 100 parts hydroxyl-terminated polybutadiene, 20 parts zinc oxide, 30 parts silica, 1.5 parts triethanolamine, 2 parts MAPO (bonding agent), 3 parts dioctyl sebacate (plasticizer), 20 parts toluene diisocyanate (curing agent), 1 ml dibutyltin dibutylsilicate (catalyst), 1.5 parts methylbutyninol (alkynyl compound), and 0.8 parts N,N'-carbonyldiimidazole (modifier).

[0051] The preparation method follows the same steps as in Example 1.

[0052] The adhesion performance of the liner material prepared in this embodiment to the azide propellant was tested, and the results are shown in Table 1.

[0053] The lining material for azide propellant prepared in this embodiment has good properties and can be used as an insulating lining for solid rocket motor casings. The method of use is the same as in Example 1.

[0054] Comparative Example 1

[0055] This comparative example provides a method for preparing a liner material for azide propellants. Compared with Example 1, the raw materials used in this comparative example do not include acetylenecyclohexanol (acetylene compound) and toluene diisocyanate (TDI, modifier). That is, unmodified chain extender is used in this comparative example, and the proportions of other raw material components are the same as in Example 1.

[0056] The preparation method includes: weighing the above-mentioned components in the prescribed amount, and mixing them in the following order: hydroxyl-terminated polybutadiene, silica, zinc oxide, chain extender, plasticizer, bonding agent, curing agent and catalyst, to obtain the final product.

[0057] The adhesion properties (including peel strength and pull-off strength) of the liner material prepared in this comparative example to the azide propellant were tested, and the results are shown in Table 1.

[0058]

[0059]

[0060] Table 1. Test results of adhesion performance between liner material and azide propellant

[0061] As can be seen from the table above, the use of the liner material provided by this invention significantly improves the interfacial adhesion performance of azide propellants.

[0062] Referring to standard QJ2038.1, and using the material provided in this comparative example, rectangular specimens for the tear test were prepared using the same preparation method and curing conditions as those for the insulation liner of a solid rocket motor. After preparation, the specimens were mounted on a testing machine, and a tensile speed of 20 mm / min was applied at room temperature until the specimen broke. The load value was recorded, and the state of the specimen after tearing was as follows. Figure 2 As shown.

[0063] from Figure 1 and Figure 2 It can be seen that the fracture location of the sample prepared in Example 1 is inside the propellant, while the fracture location of the sample prepared in the comparative example is at the propellant / liner interface. This indicates that through the modification of the chain extender, the tensile failure mode of the joint sample of propellant / liner / insulation layer changes from interfacial failure to propellant cohesive failure, proving the reliability of the interface.

[0064] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0065] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for preparing a liner material for azide propellant, characterized in that, This method uses the following raw materials, by weight, to prepare the liner material for azide propellants: The mixture contains 100-150 parts of hydroxyl-terminated polybutadiene, 40-100 parts of filler, 1-3 parts of triethanolamine, 0.5-5 parts of modifier, 2-5 parts of bonding agent, 3-5 parts of plasticizer, 10-40 parts of curing agent, 0.6-1.2 parts of catalyst and 1-3 parts of alkynyl compound. The method includes the following steps: Step 1: Add the prescribed amount of alkynyl compound dropwise to the modifier and stir thoroughly to obtain a mixed solution; Step 2: Under stirring conditions, the mixed solution is added dropwise to triethanolamine to obtain the modified chain extender; Step 3: Mix the raw materials in the prescribed amount in the following order: hydroxyl-terminated polybutadiene, filler, modified chain extender, plasticizer, bonding agent, curing agent and catalyst.

2. The preparation method according to claim 1, characterized in that, The filler is composed of 20 to 50 parts by weight of zinc oxide and 20 to 50 parts by weight of silica.

3. The preparation method according to claim 1, characterized in that, The modifier is selected from any one or more of N,N'-carbonyldiimidazole, toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate.

4. The preparation method according to claim 1, characterized in that, The bonding agent is selected from any one or more of tri-1-(2-methylaziridine)phosphine oxide, isophthaloyl(2-methylaziridine), and boron trifluoride triethanolamine complex.

5. The preparation method according to claim 1, characterized in that, The plasticizer is selected from any one of diisooctyl sebacate, dioctyl sebacate, diisooctyl phthalate, and dimethyl phthalate.

6. The preparation method according to claim 1, characterized in that, The curing agent is selected from any one of toluene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate and N-100, and the ratio of the molar number of -NCO groups to the sum of the molar numbers of -OH groups and -NH groups in the curing agent is 1.1 to 2.

7. The preparation method according to claim 1, characterized in that, The selected catalyst is chosen from one or two of triphenylbismuth, dibutyltin dilaurate, and stannous octoate.

8. The preparation method according to claim 1, characterized in that, The alkynyl compound is selected from any one of propargylamine, hepta-6-yn-1-amine, alkynyl-polyethylene glycol-amino, butynic acid, propargylic acid, methylbutynol, propargol, and ethynylcyclohexanol.

9. A liner material for azide propellant, characterized in that, The liner material for the azide propellant is prepared using the preparation method described in any one of claims 1 to 8.

10. The application of the lining material for azide propellants as described in claim 9 in the heat insulation lining of a solid rocket motor casing.

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