Polycyanogen polyhydroxyl bonding agent, preparation method and application of polycyanogen polyhydroxyl bonding agent in hydroxyl-terminated polybutadiene propellant

Abstract

The invention relates to the technical field of solid propellants, and particularly discloses a polycyanide polyhydroxyl bonding agent, a preparation method and application of the polycyanide polyhydroxyl bonding agent in a hydroxyl-terminated polybutadiene propellant.The preparation method of the bonding agent comprises the steps that acrylonitrile is dropwise added into polyethylene polyamine, and a temperature rise reaction is conducted to prepare an intermediate; and adding glyceric acid into the intermediate, heating to carry out amidation reaction, and distilling until no liquid is distilled off to obtain the target bonding agent. The bonding agent is of a polycyanide polyhydroxyl molecular structure, hydroxyl in the bonding agent and toluene diisocynate can enter a cross-linked network through chemical bonding, cyano can generate a very strong physical adsorption effect with the surfaces of nitramine oxidizing agent particles, and the bonding agent is used as a nitramine or nitramine modified hydroxyl-terminated polybutadiene solid propellant system. After the bonding agent provided by the invention is added into a solid propellant system, the normal-temperature, high-temperature and low-temperature mechanical properties of the solid propellant are obviously improved.

Description

Technical Field

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

[0002] In the process of pursuing high energy, solid propellants add oxidant particles, such as ammonium perchlorate (AP), RDX, and HMX. These oxidant particles are non-reinforcing fillers. When the propellant is subjected to a certain external load, the filler and the matrix are easily separated, resulting in "dehumidification". The essence of "dehumidification" is that the interface between the polymer binder and the solid particles is destroyed under the action of external force, and the adhesion fails, causing the binder to detach from the surface of the solid particles. The "dehumidification" phenomenon seriously affects the mechanical properties of the propellant.

[0003] The bonding agent is a key auxiliary agent that improves the interfacial bonding performance between high-energy fillers and binders, inhibits the "dehumidification" phenomenon, and thus improves the mechanical properties of propellants. The bonding agent should first have a group that can adsorb to the solid filler particles, which determines the strength of the bonding between the bonding agent and the solid filler particles; secondly, it should have a sufficient number of groups with appropriate reactivity that can react with the curing agent, which determines the bonding strength between the bonding agent and the binder system.

[0004] In order to solve the above problems, a bonding agent with an amphiphilic structure and a sufficient number of bonding groups is added to the propellant, which can react physically and chemically with the filler and combine with the matrix at the same time, thereby enhancing the interfacial bonding between the two and improving the overall mechanical properties of the propellant. At present, the bonding agents used more in the four-component butyl hydroxyl propellant are mainly borate esters and hydantoin bonding agents. Borates can absorb moisture on solid particles and hydrolyze, eliminating the weak boundary layer around the particles caused by the presence of moisture; in addition, borate ester bonding agents can also improve the high-temperature mechanical properties of the propellant, but the hydrolysis stability of borate esters is poor. Although hydantoin triazine bonding agents can significantly improve the mechanical properties of butyl hydroxyl propellant, the effect of hydantoin bonding agents at high temperatures is not good, especially in high-temperature accelerated aging tests, the mechanical properties of the grain decrease rapidly, and it is difficult to meet the application requirements of the model. Summary of the invention

[0005] The present invention provides a polycyanide-polyhydroxy bonding agent, a preparation method and application thereof in hydroxyl butadiene propellant. The bonding agent is a polycyanide-polyhydroxy molecular structure, wherein the hydroxyl groups can enter a cross-linked network through chemical bonding with toluene diisocyanate, and the cyanide groups can produce a strong physical adsorption effect with the surface of nitramine oxidant particles, and the bonding agent is used as a nitramine or nitramine-modified hydroxyl butadiene solid propellant system.

[0006] The technical solution of the present invention is to provide a polycyanide polyhydroxy bonding agent, the molecular structure of the bonding agent is as follows: ; Where n=1~4.

[0007] Optionally, n in the molecular structure formula is 1, 2, 3 or 4.

[0008] The present invention also relates to a method for preparing the polycyanide-polyhydroxy bonding agent, comprising the following steps: S1, adding acrylonitrile dropwise to polyethylene polyamine, and heating the reaction to prepare an intermediate; S2. Add glyceric acid to the intermediate, raise the temperature to carry out amidation reaction, and then distill until no liquid is distilled out to obtain a polycyanide-polyhydroxy bonding agent.

[0009] Optionally, the molar ratio of polyene polyamine to acrylonitrile in S1 is 1:2.0-2.5.

[0010] Optionally, the polyene polyamine is one or more of ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine or ethylenehexamine.

[0011] Optionally, the reaction temperature in S1 is 35 to 90° C., and the reaction time is 0.5 to 8 hours.

[0012] Optionally, the molar ratio of polyene polyamine to glyceric acid in S2 is 1:2.0~2.5.

[0013] Optionally, the amidation reaction temperature is 140 to 190° C., and the reaction time is 0.5 to 5 hours.

[0014] The invention also relates to the application of the polycyanide-polyhydroxy bonding agent in propellants.

[0015] Furthermore, the propellant is hydroxybutyrate propellant.

[0016] The present invention has the following beneficial effects: The present invention uses polyethylene polyamine as a raw material, reacts with acrylonitrile and glyceric acid, and the obtained bonding agent contains multiple hydroxyl groups and cyano groups at the same time. The hydroxyl groups react with isocyanate to enter the curing network system, and the cyano groups and nitramine molecules have a strong physical interaction, which inhibits the dissolution of nitramine molecules in the plasticizer, prevents the appearance of a "soft interface layer", and improves the mechanical properties of butyl hydroxy propellants.

[0017] The polycyanide-polyhydroxy bonding agent provided by the present invention also has good hydrolysis resistance and still has good bonding effect under high temperature environment. The preparation method of the bonding agent is simple, the reaction conditions are mild, and the reaction time is short. The obtained product has high purity and yield; the reaction process does not require additional reagents and solvents, the raw material utilization rate is high, and there is no operation such as solvent recovery, and no hazardous waste is generated in the preparation process; it is suitable for industrial production. DETAILED DESCRIPTION

[0018] 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.

[0019] The present invention provides a polycyanide polyhydroxy bonding agent, the molecular structure of the bonding agent is as follows: ; Where n=1~4.

[0020] Optionally, n in the molecular structure formula is 1, 2, 3 or 4.

[0021] The present invention also relates to a method for preparing the polycyanide-polyhydroxy bonding agent, comprising the following steps: S1, adding acrylonitrile dropwise to polyethylene polyamine, and heating the reaction to prepare an intermediate; S2. Add glyceric acid to the intermediate, raise the temperature to carry out amidation reaction, and then distill until no liquid is distilled out to obtain a polycyanide-polyhydroxy bonding agent.

[0022] In some embodiments, the molar ratio of polyene polyamine to acrylonitrile in S1 is 1:2.0-2.5; preferably 1:2.2.

[0023] In some embodiments, the polyene polyamine is one or more of ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine or ethylenehexamine, preferably pentaethylenehexamine.

[0024] In some embodiments, the reaction temperature in S1 is 35-90°C, preferably 75°C; the reaction time is 0.5-8 hours, preferably 3 hours.

[0025] In some embodiments, the molar ratio of polyene polyamine to glyceric acid in S2 is 1:2.0-2.5, preferably 1:2.1.

[0026] In some embodiments, the temperature of the amidation reaction is 140-190° C., preferably 160° C. The reaction time is 0.5-5 hours, preferably 3 hours.

[0027] 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.

[0028] Example 1 Weigh 0.5 mol of ethylenediamine in a three-necked flask, slowly drip 1.1 mol of acrylonitrile into the three-necked flask, keep the temperature at about 60°C while adding acrylonitrile, and stir continuously at a stirring speed of about 110r / min. Raise the system temperature to 70°C, stir at a speed of 130r / min, and keep warm for 3 hours to obtain an intermediate; slowly drip 1.1 mol of glyceric acid into the intermediate, keep the temperature at about 120°C while adding glyceric acid, and stir continuously at a stirring speed of about 150r / min. After the addition of glyceric acid is completed, heat to 145°C, remove water while stirring, and carry out reduced pressure distillation after keeping warm for 3 hours, control the system pressure to 0.06MPa, and end the distillation until no liquid is distilled out, and the product is the target bonding agent 1.

[0029] Example 2 Weigh 0.5 mol of diethylenetriamine in a three-necked flask, slowly drip 1.12 mol of acrylonitrile into the three-necked flask, keep the temperature at about 60°C while adding acrylonitrile, and stir continuously at a stirring speed of about 110r / min. Raise the system temperature to 70°C, stir at a speed of 130r / min, and keep warm for 3 hours to obtain an intermediate; slowly drip 1.1 mol of glyceric acid into the intermediate, keep the temperature at about 120°C while adding glyceric acid, and stir continuously at a stirring speed of about 150r / min. After the addition of glyceric acid is completed, raise the temperature to 145°C, remove water while stirring, and carry out reduced pressure distillation after keeping warm for 3 hours, control the system pressure to 0.06MPa, and end the distillation until no liquid is distilled out, and the product is the target bonding agent 2.

[0030] Example 3 Weigh 0.5 mol of triethylenetetramine in a three-necked flask, slowly drip 1.2 mol of acrylonitrile into the three-necked flask, keep the temperature at about 60°C while adding acrylonitrile, and stir continuously at a stirring speed of about 110r / min. Raise the system temperature to 70°C, stir at a speed of 130r / min, and keep warm for 3 hours to obtain an intermediate; slowly drip 1.1 mol of glyceric acid into the intermediate, keep the temperature at about 120°C while adding glyceric acid, and stir continuously at a stirring speed of about 150r / min. After the addition of glyceric acid is completed, heat to 160°C, remove water while stirring, and carry out reduced pressure distillation after keeping warm for 3 hours, control the system pressure to 0.06MPa, and end the distillation until no liquid is distilled out, and the product is the target bonding agent 3.

[0031] Example 4 Weigh 0.5 mol of tetraethylenepentamine in a three-necked flask, slowly drip 1.1 mol of acrylonitrile into the three-necked flask, keep the temperature at about 60°C while adding acrylonitrile, and stir continuously at a stirring speed of 110r / min. Raise the system temperature to 75°C, stir at a speed of 140r / min, and keep warm for 3 hours to obtain an intermediate; slowly drip 1 mol of glyceric acid into the intermediate, keep the temperature at about 120°C while adding glyceric acid, and stir continuously at a stirring speed of about 150r / min. After the addition of glyceric acid is completed, raise the temperature to 160°C, remove water while stirring, and carry out reduced pressure distillation after keeping warm for 3 hours, control the system pressure to 0.09MPa, and end the distillation until no liquid is distilled out, and the product is the target bonding agent 4.

[0032] Example 5 Weigh 0.5 mol of pentaethylenehexamine in a three-necked flask, slowly drip 1.2 mol of acrylonitrile into the three-necked flask, keep the temperature at about 60°C while adding acrylonitrile, and stir continuously at a stirring speed of 120r / min. Raise the system temperature to 75°C, stir at a speed of 140r / min, and keep warm for 3 hours to obtain an intermediate; slowly drip 1.1 mol of glyceric acid into the intermediate, keep the temperature at about 120°C while adding glyceric acid, and stir continuously at a stirring speed of about 150r / min. After the addition of glyceric acid is completed, heat to 180°C, remove water while stirring, and carry out reduced pressure distillation after keeping warm for 3 hours, control the system pressure to 0.09MPa, and end the distillation until no liquid is distilled out, and the product is the target bonding agent 5.

[0033] Comparative Example 1 Weigh 0.25 mol of polypropylene glycol diglycidyl ether-400, and drip 0.53 mol of pentaethylene hexamine into a three-necked flask. After the addition, control the temperature to 40°C. After reacting for 4 hours, cool to room temperature. Slowly drip 1.2 mol of acrylonitrile into the three-necked flask, while adding acrylonitrile, keep the temperature at about 60°C, and stir continuously at a stirring speed of 120r / min. Raise the system temperature to 75°C, stir at a speed of 140r / min, and keep warm for 3 hours to obtain.

[0034] The bonding agents obtained in the above examples and comparative examples were respectively applied to a certain formula of a hydroxybutane four-component propellant (solid content 88%), and the amount of the bonding agent added was 0.05% of the hydroxybutane four-component propellant; the mechanical properties test results are shown in Table 1 (the test reference standard is GJB770B-2005).

[0035] Table 1 Mechanical properties of different bonding agents

[0036] It can be seen from the data in Table 1 that, compared with the blank sample (without adding a bonding agent) and polypropylene glycol diglycidyl ether-400 with a low hydroxyl content, after adding the bonding agent provided by the present invention to the solid propellant system, the room temperature, high and low temperature mechanical properties of the solid propellant are significantly improved, indicating that the bonding agent prepared by the present invention has a good bonding effect on the butyl hydroxyl propellant system containing ammonium nitrate under the action of multiple cyano groups and hydroxyl groups.

[0037] 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. A polycyano-polyhydroxy bonding agent, characterized in that: The molecular structure of the bonding agent is as follows: ； Where n=1~4.

2. The polycyanide-polyhydroxy bonding agent according to claim 1, characterized in that: In the molecular structural formula, n is 1, 2, 3 or 4.

3. The method for preparing the polycyanide-polyhydroxy bonding agent according to claim 1 or 2, characterized in that: The following steps are involved: S1, adding acrylonitrile dropwise to polyethylene polyamine, and heating the reaction to prepare an intermediate; S2. Add glyceric acid to the intermediate, raise the temperature to carry out amidation reaction, and then distill until no liquid is distilled out to obtain a polycyanide-polyhydroxy bonding agent.

4. The preparation method according to claim 3, characterized in that: The molar ratio of polyene polyamine to acrylonitrile in S1 is 1:2.0-2.

5.

5. The preparation method according to claim 3, characterized in that: The polyene polyamine is one or more of ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine or ethylenehexamine.

6. The preparation method according to any one of claims 3 to 5, characterized in that: In S1, the reaction temperature is 35 to 90° C., and the reaction time is 0.5 to 8 hours.

7. The preparation method according to claim 3, characterized in that: The molar ratio of polyene polyamine to glyceric acid in S2 is 1:2.0~2.

5.

8. The preparation method according to claim 7, characterized in that: The temperature of the amidation reaction is 140 to 190° C., and the reaction time is 0.5 to 5 hours.

9. Use of the polycyanide-polyhydric bonding agent according to claim 1 or 2 or the polycyanide-polyhydric bonding agent obtained by any one of the preparation methods of claims 3 to 8 in propellants.

10. The use according to claim 9, characterized in that: The propellant is hydroxybutyrate propellant.

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