Organosilane bonding agent, preparation method thereof and application of organosilane bonding agent in solid propellant

Abstract

The invention relates to the technical field of solid propellants, and particularly discloses an organosilane bonding agent as well as a preparation method and application thereof in a solid propellant. The preparation method of the organosilane bonding agent comprises the following steps: reacting N-(beta-aminoethyl)-gamma-aminopropyl trimethoxy silane with acrylonitrile, adding acrylonitrile, reacting, and carrying out reduced pressure distillation to remove unreacted small molecular compounds, so as to prepare the organosilane bonding agent. Siloxane in the organosilane bonding agent avoids high-activity primary amine groups and secondary amine groups, meanwhile, cyano groups with an induction effect are introduced, stress concentration of the propellant under the tensile condition can be improved, in addition, multiple hydroxyl groups are introduced into molecules and can participate in a curing reaction, when the organosilane bonding agent is used for the propellant, the crosslinking density of the propellant can be improved, and the propellant tensile strength can be improved. Therefore, the mechanical property of the propellant is improved.

Description

Technical Field

[0001] The invention relates to the technical field of solid propellants, and in particular to an organosilane bonding agent and a preparation method thereof and application thereof in solid propellants. Background Art

[0002] Bonding agent is an indispensable auxiliary agent in composite propellant. It improves the interface between oxidant and adhesive and inhibits the interface "dewetting" phenomenon of propellant, thus ensuring the stability and reliability of propellant.

[0003] At present, the main propellant bonding agents include aziridine compounds, alkanolamine compounds, borate compounds, polyamine compounds, neutral polymers, organic phthalates and organosilanes. The siloxane of the organosilane bonding agent can react with water on the surface of the filler to form silanol, which can adsorb on the surface of the filler to play a bonding role. Most of the existing silane bonding agents are silane bonding agents containing primary or secondary amine groups, such as N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane. The primary and secondary amine groups have too high reactivity and can react quickly with isocyanates, resulting in a decrease in the process performance of the propellant. Therefore, this type of silane coupling agent is usually used to treat coated AP. In addition, this type of silane bonding agent lacks an inducing group and cannot release the stress concentration point of the propellant, which is not conducive to the mechanical properties of the propellant. Therefore, it is of great application value to develop an organosilane bonding agent with little effect on the process performance of the propellant and excellent effect. Summary of the invention

[0004] The invention provides an organic silane bonding agent and a preparation method thereof and application in solid propellants, which have the characteristics of low activity and no influence on the process performance of the propellant.

[0005] The technical solution of the present invention is to provide an organosilane bonding agent, the molecular structure of the organosilane bonding agent is as follows: ; Wherein, R is one of the functional groups -OH, -OCH2CH2CH3, -OCH2CH=CH2 or -OCH2CH2CH2Si(OCH3)3.

[0006] The present invention also relates to a method for preparing the organosilane bonding agent, comprising the following steps: S1, using N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane as a raw material, mixing it with acrylonitrile for reaction; S2, S1 obtained material added modified glycidyl ether to react again, after the reaction is completed, distilled to remove the unreacted small molecular compounds, the remaining light yellow or yellow viscous liquid is the organosilane bonding agent.

[0007] Optionally, the molar ratio of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane to acrylonitrile in S1 is 1:1.00-1.10.

[0008] Optionally, the reaction temperature in S1 is 30-50° C., the reaction time is 3-5 hours, and after the reaction is completed, the mixture is cooled to room temperature before proceeding to the next step.

[0009] Optionally, the amount of modified glycidyl ether added in S2 is 2.00 to 2.20 times the molar amount of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane.

[0010] Alternatively, the modified glycidyl ether includes, but is not limited to, glycidol, n-propyl glycidyl ether, allyl glycidyl ether or γ-glycidyloxypropyltrimethoxysilane.

[0011] Optionally, the reaction temperature in S2 is 30-50° C., and the reaction time is 3-5 hours.

[0012] Optionally, the distillation temperature in S2 is 70-90°C.

[0013] The invention also relates to application of the obtained organic silane bonding agent in composite solid propellant.

[0014] Optionally, the amount of the organic silane bonding agent added is 0.05-0.1%.

[0015] The present invention has the following beneficial effects: The siloxane in the organosilane bonding agent of the present invention contains only tertiary amines, thereby avoiding highly active primary and secondary amine groups and being unable to react with isocyanate in the propellant. At the same time, the present invention introduces a cyano group with an inductive effect into the organosilane bonding agent, which can improve stress concentration under tensile conditions of the propellant. In addition, multiple hydroxyl groups are introduced into the molecule to participate in the curing reaction, thereby increasing the crosslinking density of the propellant and thus improving the mechanical properties of the propellant.

[0016] The organosilane bonding agent provided by the present invention has the advantages of simple synthesis method, mild reaction conditions and the like. DETAILED DESCRIPTION

[0017] The experimental methods in the following examples are conventional methods unless otherwise specified. The raw materials, reagents, etc. used in the following examples are commercially available products unless otherwise specified.

[0018] The present invention provides an organosilane bonding agent, the molecular structure of which is as follows: ; Wherein, R is one of the functional groups -OH, -OCH2CH2CH3, -OCH2CH=CH2 or -OCH2CH2CH2Si(OCH3)3.

[0019] The present invention also relates to a method for preparing the organosilane bonding agent, comprising the following steps: S1, using N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane as a raw material, mixing it with acrylonitrile for reaction; S2, S1 obtained material added modified glycidyl ether to react again, after the reaction is completed, distilled to remove the unreacted small molecular compounds, the remaining light yellow or yellow viscous liquid is the organosilane bonding agent.

[0020] In some embodiments, the molar ratio of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane to acrylonitrile is 1:1.00-1.10, preferably 1:1.05. In S1, the reaction temperature is 30-50°C, the reaction time is 3-5 hours, and after the reaction is completed, the reaction is cooled to room temperature before the next step.

[0021] In some embodiments, the amount of modified glycidyl ether added in S2 is 2.00-2.20 times the molar amount of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane; the modified glycidyl ether includes but is not limited to glycidol, n-propyl glycidyl ether, allyl glycidyl ether or γ-glycidyloxypropyltrimethoxysilane; the reaction temperature in S2 is 30-50°C, and the reaction time is 3-5 hours. The distillation temperature is 70-90°C.

[0022] The present invention is described in detail below in conjunction with specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and a specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0023] Example 1 (1) Weigh 0.50 mol of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, add it into a three-necked reaction bottle, and slowly add 0.50 mol of acrylonitrile through a dropping funnel. After the addition is complete, the reaction temperature of the system is controlled to be 40°C. After the reaction is carried out for 3 hours, cool to room temperature; (2) Slowly add 1.10 mol of allyl glycidyl ether to the product of step 1. After the addition is complete, continue to heat the system to 40°C, react for 4 hours, and then distill under reduced pressure at 70°C to remove unreacted small molecular compounds. After cooling to room temperature, the target yellow viscous liquid product can be obtained. Example 2 (1) Weigh 0.50 mol of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, add it into a three-necked reaction bottle, and slowly add 0.52 mol of acrylonitrile through a dropping funnel. After the addition is complete, the reaction temperature of the system is controlled to be 40°C. After the reaction is carried out for 5 hours, cool to room temperature; (2) Slowly add 1.02 mol of propylene oxide to the product of step 3. After the addition is complete, continue to heat the system to 50°C. After reacting for 2 hours, remove the unreacted small molecule compounds by vacuum distillation at 90°C. After cooling to room temperature, the target light yellow viscous liquid product can be obtained.

[0024] Example 3 (1) Weigh 0.50 mol of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, add it into a three-necked reaction bottle, and slowly add 0.53 mol of acrylonitrile through a dropping funnel. After the addition is complete, the reaction temperature of the system is controlled to be 50°C. After the reaction is carried out for 3 hours, cool to room temperature; (2) Slowly add 1.08 mol of n-propyl glycidyl ether to the product of step 3. After the addition is complete, continue to heat the system to 40°C, react for 4 hours, and then distill under reduced pressure at 90°C to remove unreacted small molecular compounds. After cooling to room temperature, the target yellow viscous liquid product can be obtained.

[0025] Example 4 (1) Weigh 0.50 mol of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, add it into a three-necked reaction bottle, and slowly add 0.55 mol of acrylonitrile through a dropping funnel. After the addition is complete, the reaction temperature of the system is controlled to be 30°C. After the reaction is carried out for 4 hours, cool to room temperature; (2) Slowly add 1.05 mol of γ-glycidyloxypropyltrimethoxysilane to the product of step 3. After the addition is complete, continue to heat the system to 40°C, react for 4 hours, and then distill under reduced pressure at 80°C to remove unreacted small molecular compounds. After cooling to room temperature, the target yellow viscous liquid product can be obtained.

[0026] The organosilane bonding agent obtained in the above examples and comparative examples is used in a butyl hydroxy four-component formula. In the propellant (solid content 88.0%), the amount of bonding agent added is 0.08%. The properties of the obtained propellant are shown in Table 1.

[0027] Table 1 Application performance of organosilane bonding agent

[0028] It can be seen from Table 1 above that the organosilane bonding agent of the present invention has good application performance.

[0029] The above embodiments describe the preferred implementation of the present invention, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An organosilane bonding agent, characterized in that: The molecular structure of the organosilane bonding agent is as follows: ； Wherein, R is one of the functional groups -OH, -OCH2CH2CH3, -OCH2CH=CH2 or -OCH2CH2CH2Si(OCH3)3.

2. The method for preparing an organosilane bonding agent according to claim 1, characterized in that: The following steps are involved: S1, using N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane as a raw material, mixing it with acrylonitrile for reaction; S2, S1 obtained material added modified glycidyl ether to react again, after the reaction is completed, distilled to remove the unreacted small molecular compounds, the remaining light yellow or yellow viscous liquid is the organosilane bonding agent.

3. The method for preparing the organosilane bonding agent according to claim 2, characterized in that: The molar ratio of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane to acrylonitrile in S1 is 1:1.00~1.

10.

4. The preparation method according to claim 2 or 3, characterized in that: In S1, the reaction temperature is 30-50°C, the reaction time is 3-5 hours, and after the reaction is completed, the reaction is cooled to room temperature before proceeding to the next step.

5. The preparation method according to claim 2, characterized in that: The amount of modified glycidyl ether added in S2 is 2.00 to 2.20 times the molar amount of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane.

6. The preparation method according to claim 2, characterized in that: The modified glycidyl ether includes, but is not limited to, glycidol, n-propyl glycidyl ether, allyl glycidyl ether or γ-glycidyloxypropyltrimethoxysilane.

7. The preparation method according to claim 2, characterized in that: In S2, the reaction temperature is 30-50°C and the reaction time is 3-5 hours.

8. The preparation method according to any one of claims 3 to 7, characterized in that: The distillation temperature in S2 is 70~90℃.

9. Use of the organosilane bonding agent obtained according to claim 1 or the organosilane bonding agent obtained by the preparation method according to any one of claims 2 to 8 in composite solid propellants.

10. The use according to claim 9, characterized in that: The amount of the organosilane bonding agent added to the propellant is 0.05%~0.1%.

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