KR100503894B1 - Composite for solid propellant - Google Patents

Abstract

The present invention relates to a solid propellant composition used in a rocket propulsion engine, and uses a suitable amount of bismuth trioxide, which is capable of imparting fire resistance of paper or polymer, to a propellant using butadiene to pass a fracture test. Propellant composition was constructed.

Description

Solid propellant composition {COMPOSITE FOR SOLID PROPELLANT}

The present invention relates to a new solid propellant composition that can be used in a solid rocket propulsion engine that must be insensitive to bullet impact, and specifically contains Butacene (hereinafter referred to as butacene) and bismuth trioxite (Bi ₂ O ₃ ). One solid propellant composition is disclosed.

A propulsion engine is a device that supplies the energy needed to reach a target to the aircraft. The propulsion engines can be classified into rocket propulsion engines, artillery propulsion engines and air intake propulsion engines. The rocket propulsion engines are chemical propulsion and non-chemical propulsion engines. It is classified as a driving agency. Among them, the solid propulsion engine has been widely applied as a propulsion engine such as guided coal because of its simple structure, easy handling, and excellent reliability and storage.

The solid propulsion engine consists of a propellant filler and a nozzle assembly, which includes a propellant for generating combustion gas and a combustion tube resistant to high pressure gas, a liner for bonding the propellant and the combustion tube, an insulation to protect the combustion tube from hot gas, and a propellant. Ignition device is installed. The nozzle assembly consists of a nozzle structure that resists high pressure gas and a nozzle heat resistant material that protects the nozzle structure from high temperatures, and sometimes a TVC device (Thrust Vector Control Device) for controlling the thrust direction.

Ballistics performance is an important core technology for designing the performance of solid propulsion engines.The propellant is selected to meet the system design requirements such as thrust and operating time of the missile, total area, length and diameter of the missile, and the grain shape of the propellant. And the nozzle inner surface shape. The optimum grain shape is designed through erosion combustion and combustion instability analysis in the combustion chamber and the aging characteristics analysis by stress analysis of the propellant, and the optimum nozzle inner shape is designed through the flow analysis in the nozzle.

Meanwhile, the propellant is classified into a double base and a composite. Regeneration type propellants have been mainly used in small short-range missiles because their main components consist of nitroglycerin and nitrocellulose, and they have relatively low smoke during combustion. Mixed type propellants are made by mixing oxidant powder with polymer binder and have high non-thrust and density. It is widely used in guided missiles because of its excellent mechanical properties and control of combustion speed. Recently, the development of high-energy propellants with increased energy has been spurred, and researches to increase the combustion speed are actively underway.

When a propulsion engine collides with a fast metal body such as a bullet, various phenomena occur depending on the size of the propulsion engine, the case and the characteristics of the propellant. Ideally, if nothing happens after the bullet hits the propulsion engine, in reality one of the reactions, such as burning, deflagration, explosion or detonation occurs.

The desensitization technology of solid rocket propulsion engines can be largely divided into case related technology and technology related to propellant composition, and these two technologies can be properly used to show a target combustion reaction.

In order to build a bullet-insensitive solid rocket propulsion engine to satisfy the bullet impact test, at least the propellant properties must pass the friability test in UN Test series 7. This friability test impedes a cylindrical propellant specimen 18 mm in diameter and 9 g in weight at a speed of 150 m / s on a 20 mm thick steel plate, captures the deformed propellant, and weighs 0.5 g of black powder with an average diameter of 0.75 mm. An ignition bag consisting of a hot wire (M 100) and a hot air (M 100) were used to burn in a closed bomb capable of measuring 108 cc in volume and measuring pressure change per hour. At this time, calculate the maximum value of dP / dt, which is the rate of pressure increase per unit time, from the measured pressure change data. In the UN Test series 7, the criterion for passing the crush test is an average of 15 MPa / ms or less of the maximum dP / dt results from the closed container test after testing at a collision speed of 150 m / s.

There is an urgent need to develop new solid propellant compositions that pass such fracture tests.

Accordingly, an object of the present invention is to provide a solid propellant composition which is insensitive to bullet impact and is used in a rocket propulsion engine that satisfies the fracture test standard in the UN Test series 7.

In order to achieve the above object, the present invention provides ammonium nitrate (AN), hexanitro hexaazaisobutytan (hexanitro hexaaza isowurtzitane (HNIW)) in a content of 45% to 97.5% as a filler, and phase stabilized ammonium nitrate ( phase stabilized ammonium nitrate (PSAN), ammonium dinitramide (ADN), cyclo trimethylene tetranitramine (HMX), cyclotrmethylene trinitramine (RDX), ammonium perchlorate (ammoniun perchlorate: any one or more substances selected from AP); Hydroxyterminated polybutadiene (HTPB) in a content of greater than 0% and up to 20% as a prepolymer; Butacene in a content of 0.5 to 10% as a combustion catalyst; And 2 to 15% content of bismuthrioxide.

Butacene refers to a French SNPE product as a material used as a combustion catalyst and a binder (prepolymer) of the AP propellant.

The composition may further comprise ZrC in the range of more than 0% to 5%. ZrC is a combustion stabilizer that eliminates instability when combustion instability occurs in the propulsion engine.

In addition, the composition may include 0 to 30% of Al, Zr, B, Pb to increase the specific force and density of the propellant to increase the performance of the propellant.

The prepolymer may further include any one or more materials selected from dimer diisocyanante (DDI), isophorone diisocyanante (IPDI) or hexamethylene diisocyanate (HDI) as a curing agent. . The content of the curing agent relative to the prepolymer is expressed by the ratio of NCO / OH, the range of 0.8 ~ 1.1 is preferred.

On the other hand, the composition is a plasticizer dioctyl sebacate (DOS), dioctyl adipate (dioctyl adipate (DOA), isodecyl pelargonate (IDP), or BuNENA (Nn-Butyl-N- (2-nitratoethyl) nitramine) may further include any one or more substances selected from. The preferred amount of plasticizer relative to the total propellant is 0% to 5%.

In addition, the composition is a bisisophtanyl-methyl-aziridine (HX-752), trimesoyl-1- (2-ethyl) aziridine (HX-) as a binder 868), TEPANOL or bis-hydroxyethyl glycol amide (BHEGA) may further include any one or more materials selected from. The preferred amount of binder relative to the total propellant is 0.01% to 0.5%.

Butacene is a very good catalyst for increasing the burning rate of solid propellants, especially HTPB / AP propellants, and bismuth trioxide is a high density material used as a fireproof additive in paper or polymers.

When the two propellants are mixed with an appropriate amount of a solid propellant to prepare a propellant, it is possible to prepare a solid propellant having excellent combustion performance and mechanical properties as well as excellent friability characteristics.

Combustion rate of AP propellant is determined by the AP particle size and the content of butacene, and the combustion speed increases as the content of AP decreases but the content of butadiene increases. However, when the propellant is constructed in the above direction to increase the combustion rate, the mechanical properties are degraded and the fracture test cannot be passed. Furthermore, a composition with a butadiene content of more than about 4% results in combustion at a coal speed of 135m / s when the specimen collides with the steel sheet.

Therefore, in order for the propellant using butadiene to pass the crushing test, the content of butadiene must be less than 4%, the mechanical properties must be good, and the impulse-density of the propellant must be satisfactory.

In the present invention, bismuth trioxide, which has high density and can impart fire resistance to paper or polymer, is used in place of AP to form a propellant composition.

Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1.

A propellant of AP 85.5%, ZrC 1.5%, HTPB / IPDI 4.15%, butadiene 5.5%, dioctyl adipate 3.0%, TEPANOL 0.1% as a binder and AO2246 0.25% as an antioxidant was prepared.

As a result of the characteristic test, the combustion speed was 41.1 mm / s, pressure index 0.392, tensile strength 8.6 bar, strain 34%, elastic modulus 42 bar, density 1.73 g / cc at 1500 psia (20 ℃). burned at / s.

Example 2.

A propellant of AP 80.5%, Bi ₂ O ₃ 5%, HTPB / IPDI 9.40%, dioctyl adipate 3.0%, ZrC: 1.5%, TEPANOL 0.4% as a binder and AO2246 0.2% as an antioxidant was prepared.

As a result of the characteristic test, the combustion rate was 13.6 mm / s, pressure index 0.419, tensile strength 11.6 bar, strain 49%, modulus of elasticity 39 bar, density 1.79 g / cc at 1500 psia (20 ℃). dt = 11.82 MPa / ms.

Example 3.

A propellant was prepared having a composition of AP 75.5%, Bi ₂ O ₃ 10%, HTPB / IPDI 9.40%, dioctyl adipate 3.0%, ZrC: 1.5%, TEPANOL 0.4% as binder and AO2246 0.2% as antioxidant.

As a result of the characteristic test, the combustion rate was 13.72 mm / s, pressure index 0.4305, tensile strength 9.0 bar, strain 48%, modulus of elasticity 28 bar, density 1.84 g / cc at 1500 psia (20 ℃). dt = 10.65 MPa / ms.

Example 4.

A propellant of AP 85.5%, butadiene 3.0%, HTPB / IPDI 6.7%, dioctyl adipate 3.0%, ZrC: 1.5%, TEPANOL 0.1% as a binder, AO2246 0.2% as an antioxidant was prepared.

As a result of the characteristic test, the combustion rate was 27.02 mm / s, pressure index 0.3454, tensile strength 13.2 bar, strain 29%, modulus 79 bar, density 1.73 g / cc at 1500 psia (20 ℃). dt = 22.93 MPa / ms.

Example 5.

Propellants were prepared with AP 81.0%, Bi ₂ O ₃ 5.0%, butadiene 3.0%, HTPB / IPDI 6.2%, dioctyl adipate 3.0%, ZrC 1.5%, TEPANOL 0.1% as binder and AO2246 0.2% as antioxidant. .

As a result of the characteristic test, the combustion rate was 24.07 mm / s, pressure index 0.3271, tensile strength 9.5 bar, strain 44%, modulus 34 bar, density 1.80 g / cc at 1500 psia (20 ℃). dt = 13.86 MPa / ms.

From the experimental results, it can be seen that when the butadiene and bismuthrioxide are used together with the solid propellant, the fracture properties are excellent and the test criteria can be satisfied.

As described above, the present invention has excellent fracture properties by using butadiene together with bismuthrioxide in a solid propellant composed of a filler and a polymer, and satisfies the fracture test standard in the UN Test series 7. Therefore, it is possible to manufacture a rocket propulsion engine insensitive to bullet impact.

Claims (11)

Ammonium nitrate (AN), hexanitro hexaaza isowurtzitane (HNIW), phase stabilized ammonium nitrate (PSAN) in a content of 45% to 97.5% as a filler Any one selected from dinitramide (ammonium dinitramide: ADN), cyclo trimethylene tetranitramine (HMX), cyclotrimethylene trinitramine (RDX), and ammonium perchlorate (AP) The above substances; Hydroxyterminated polybutadiene (HTPB) in a content of greater than 0% and up to 20% as a prepolymer; Butacene in a content of 0.5-4.0% as a catalyst; And Composed of 2 to 15% bismuthrioxide Solid propellant compositions. The solid propellant composition of claim 1, wherein said composition further comprises ZrC. The solid propellant composition of claim 2, wherein the content of ZrC is in the range of greater than 0% and 5%. The solid propellant composition of claim 1, wherein said composition further comprises Al, Zr, B or Pb. The solid propellant composition according to claim 4, wherein the content of Al, Zr, B or Pb is in the range of more than 0% to 30%. The method of claim 1, wherein the prepolymer is at least one material selected from dimer diisocyanante (DDI), isophorone diisocyanante (IPDI) or hexamethylene diisocyanate (HDI) as a curing agent. Further comprising a solid propellant composition. The solid propellant composition of claim 6, wherein the ratio of curing agent to prepolymer is determined such that the NCO / OH value is between 0.8 and 1.1. The method of claim 1, wherein the composition is selected from dioctyl sebacate (DOS), dioctyl adipate (DOA), isodecyl pelargonate (IDP), or BuNENA as a plasticizer. A solid propellant composition further comprising any one or more materials. The solid propellant composition of claim 8, wherein the content of plasticizer is in the range of greater than 0% and 5%. The composition of claim 1, wherein the composition is a bis-isophthanyl-1-methyl-aziridine (HX-752), trimesoylethylaziridine (trimesoyl-1- (2-ethyl) as a binder. aziridine: HX-868), tepanol (TEPANOL) or bis-hydroxyethyl glycol amide (bis-hydroxyethyl glycol amide: BHEGA) further comprises a solid propellant composition further comprising. The solid propellant composition of claim 10, wherein the binder content is in the range of 0.01% to 0.5%.