JPS62265192A - High energy binder type composite propellant - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] (Industrial application field) FIELD OF THE INVENTION The present invention relates to imposito propellants.

Specifically, the present invention relates to a high-energy binder-type composite propellant whose main component is a specific polyether having a methyl azide group in its side chain, and whose physical properties are improved without deteriorating its combustion properties.

(Prior art) Composite propellants have a composition whose main components are an oxidizing agent and a binder that serves as its matrix and fuel, with metal powder added as a combustion improver if necessary, and it has excellent combustion properties. Due to its properties and physical properties, it is widely used as a propellant for high performance rocket motors. Typical oxidizing agents used include ammonium perchlorate, nitramine, and ammonium nitrate, and binders include:
Polybutadiene, polycrethane, etc. are used. Also, aluminum powder or the like is used as a combustion aid.

Improvements in the combustion performance of composite solid propellants can be achieved by using components with superior combustion characteristics for each of these components.

However, in practical terms, oxidizing agents and combustion improvers are limited to the above-mentioned types due to restrictions such as their stability, safety, and toxicity. Therefore, in recent years, research has been actively conducted on high-energy binder-type composite solid propellants in which the combustion performance of propellants is improved by containing high-energy binder components. for example.

A propellant containing a binder in which a high energy plasticizer such as 0 plasticizer is added to polyurethane, which is a common binder component, has been studied, but in this case, the amount of plasticizer is As it increases.

There was a problem that the physical properties of the propellant deteriorated.

Therefore, recently, a propellant in which the prepolymer itself having a functional group, which is the main component of the binder, is made to have high energy has been studied. As a typical prepolymer, polyethers with terminal hydroxyl groups having azide groups have been studied, and among them, aliphatic polyethers with terminal hydroxyl groups having methyl azide groups in the side chains are disclosed in US Pat. No. 4,268,450. It seems very promising in practical terms. The polyether is represented by the following general formula.

Here, X is from 10 to 60.

This polyether has the following advantages and characteristics when viewed as a prepolymer for a propellant binder.

(1) The heat of formation is high.

(2) High density.

(3) High nitrogen content.

It has also been confirmed that it has far superior stability and safety compared to conventional organic azides.

Regarding (1), the combustion characteristics of the propellant.

It contributes to an increase in specific impulse, and (2) similarly leads to an increase in density and specific impulse. (3) is because a large amount of N2 gas is generated when the binder is decomposed and burned, contributing to an increase in the specific impulse of the propellant, and the proportion of carbon and hydrogen atoms is small compared to other binders. , the amount of oxidizer in the propellant, i.e.
Since the proportion of solid content is small and the viscosity of the propellant slurry is reduced, this contributes to improving the productivity of the propellant.

(Problems to be Solved by the Invention) However, when the polyether represented by the formula (n) is used as a propellant binder as described above, it has very good combustion characteristics and manufacturability. However, there was a major problem in that the physical properties of the propellant at low temperatures were extremely poor.

As a result of intensive research taking into account the above problems, the present inventors discovered that ethylene oxide, propylene oxide, or
The present invention was developed based on the knowledge that a propellant containing as a binder a polyether prepared by addition polymerizing a specific amount of one of the above significantly improves the physical properties at low temperatures without reducing its combustion performance. completed.

(Means for Solving the Problems) Namely, one aspect of the present invention is to use a high-energy binder in which the main component of the binder is a terminal hydroxyl group aliphatic polyether having a methyl azide group in the side chain in a composite propellant.

The terminal hydroxyl group aliphatic polyether is general formula (In the formula, ?I represents 10 to 33. +t represents 1 to J3.

) The present invention relates to a high-energy binder type composite propellant characterized by the following:

Here, if n is less than io in general formula (1), elongation among the physical properties of the propellant will decrease. 33 outside
If it exceeds that, the tensile strength also decreases among the physical properties,
In addition, since the viscosity of the polyether increases, the productivity of the propellant tends to deteriorate. Preferably, n=/
'A to 30 range.

Moreover, if m+t exceeds Jj, the combustion performance of the propellant will deteriorate. Preferably, %4-L is from s
It is in the range of X/,Q.

The polyether represented by the general formula (1) is contained in the propellant from 7 to
It is preferable that the propellant is contained in a weight of 30 weight, and if it is less than 7 weight, or if it exceeds 30 weight, the specific impulse of the propellant will decrease in either case. More preferably, the weight range is 10-M.

An example of a method for synthesizing polyether represented by the general formula (Natsu) will be given below. As a reaction initiator, a reaction catalyst is dissolved in a diol consisting of ethylene glycol, glopylene glycol, α-monochlorohydrin, and their polymers, into a system,
Epichlorohydrin and ethylene oxide or propylene oxide, or epichlorohydrin, ethylene oxide, and propylene oxide are subjected to an addition reaction to synthesize a terminal hydroxyl group aliphatic polyether having a chloromethyl group in the side chain. Next, the polyether represented by the general formula (1) is obtained by reacting the polyether and sodium azide in a solvent at a predetermined temperature for 1 hour.

The obtained polyether was confirmed to have a structure represented by the general formula (1) by single-element analysis, infrared absorption spectrometry, molecular weight measurement, chemical ring analysis of hydroxyl groups, and various other analyses.

In addition to the above-mentioned polyether, the binder in the propellant of the present invention includes a crosslinking agent and a curing agent, and if necessary, a plasticizer, an oxidizing agent, a binder that imparts adhesion to the binder, a curing catalyst, an anti-aging agent, etc. It is composed of additives.

As a crosslinking agent, trimethylolpropane (TMP)
, polyether triol, polyester triol, and other polyfunctional polyols having a J-functionality or higher, and preferred are TMP and trifunctional polyols having a molecular weight of 1000 or less.

As a curing agent, for example, hexamethylene diisocyanate (HMDI), influoron diisocyanate (I
PDI), tolylene diisocyanate, and other diisocyanate compounds.

Preferably it is HMD I or XPDx.

Examples of plasticizers include esters such as dioctyl adipate (DOA), dioctyl adipate (DO8), diisodecyl adipate (DIDA), and isodecyl perabonate (L'e2*daptantriol trinitrate).
Nitroplasticizers such as (BTTN), trimethylolethane trinitrate (TMETN), and )lyethylene glycol dinitrate (TEGDN) are used.

As a binder, bisisophthaloyl 1-(comethyl)
Aziridine series such as aziridine (HX-7!Co, manufactured by JM Company), reaction products of tetraethylenepentamine and acrylonitrile (TEPAN or HX-t lid, manufactured by 3M Company),
The reaction product of tetraethylenepentamine with acrylonitrile and glycidol (TgpANoL or HX-1
7g, manufactured by 3M), hydantoin systems such as dihydroxyethyl j, s dimethylhydantoin (DIE), and silane coupling agents (A-ttoo, manufactured by Nippon Unicar) as O curing catalysts. is 1, for example, dibutyltin silacrate (
Organic tin compounds such as DBTDL), dibutyltin di(coethylhexoate), and amines such as triethylenediamine are used.

Examples of anti-aging agents include 1, 2'-methylene-bis(damethyl-6-tert-butylphenonyl), phenyl-β-7-7-thylamine, and a reaction product of diphenylamine with acetone (Non-7Rex BA, Seiko Chemical Co., Ltd.). company) etc.

When producing a composite propellant, the above-mentioned binder is usually used in an amount of io to 3j% by weight, an oxidizing agent is added thereto, and if necessary, the performance is increased to v'! Combustion aids and combustion modifiers are added to stabilize the combustion.

The oxidizing agent is usually ammonium perchlorate (AP)%
Cyclotetramethylenetetranitramine (I(MX))
, cyclotrimethylenetrinitramine (RDX), lyaminoguanidine nitrate (TAGN), and ammonium nitrate (AN).

Note that AP and AN may be coated with a thermosetting resin such as an epoxy resin or a thermoplastic resin such as polyvinyl chloride in order to prevent the reaction between the moisture contained therein and the isocyanate which is a curing agent.

As the combustion improver, metal powder such as aluminum or boron is used, and as the combustion modifier, iron oxide, hexagonal locene derivatives, carborane derivatives, lead salts, carbon, etc. are used.

The proportions of each component of the high energy binder composite propellant of the present invention are generally as follows. 1 binder
0-J! The weight range and oxidizing agent are 6S to 90 weight tatami,
If necessary, a combustion improver is included in the S-X weight pot, and various additives such as a combustion modifier are included in the amount.

The high energy binder composite propellant of the present invention can be obtained by a conventional manufacturing method using raw materials corresponding to the above components.

(Operations and Effects of the Invention) The high-energy binder composite propellant of the present invention has lower combustion characteristics than the conventionally known propellant containing polyether represented by the formula (If) and having high combustion performance. The physical properties at low temperatures are significantly improved without causing any damage. It has been proven through Examples and Comparative Examples that this effect is due to the action of a polymer in which at least one of ethylene oxide and propylene oxide is addition-polymerized to the main chain of the polyether represented by the formula (...). There is.

(Example) The present invention will be specifically explained below using examples. .

Example 1 (Synthesis of polyether represented by general formula (1)) First,
Polyether, which is the main component of the binder, was manufactured as follows.

Into an airtight reaction vessel were placed 6 g of ethylene glycol and 10 J g of an ether complex salt of boron trifluoride, and then added epichlorohydrin (P:CH) and ethylene oxide (
EO) to FJCH:EO=10:! ,! (molar ratio) 25 g of the mixture was added to a reaction vessel under heating at nJOC to 60° C. and under pressure of O, S to 5.0 g in a nitrogen gas atmosphere. The reaction product was then heated to 70-90°C and unreacted ECH and EOI were removed under reduced pressure. Furthermore, the catalyst was neutralized with a 10% aqueous sodium carbonate solution, and the pH was adjusted to 5-5. Then 10-1
After heating to 00°C, water was removed under reduced pressure, and filtration MR was performed to obtain a pale yellow transparent liquid E CII-K O copolymer 2.00y'.
r- got it. This product had a water content of 1:1.

Next, the ECH-EO copolymer 1500σ and sodium azide/Og were reacted in DMF at 700° C. for 72 hours. Thereafter, the mixture was cooled to room temperature, diluted with methylene chloride, and washed with distilled water to remove DMF and unreacted sodium azide. Next, water was removed with sodium sulfate, then filtered and methylene chloride was removed under reduced pressure to obtain an amber transparent liquid polyether i:t.
I got oo g.

(Physical properties of polyether) The liquid prepolymer obtained by the above method was subjected to elemental analysis 1.
Through various analyzes such as molecular weight measurement, infrared absorption analysis, and chemical analysis of water dispersion groups, the general formula (γL = n = 21),
tn = //, L = 0. It was confirmed that it was a terminal hydroxyl group aliphatic polyether with a methyl azide group in the side chain. The analytical values of this polyether are shown below.

Elemental analysis results: CJ9. A Hj, 9 N33. The
(wt%) Molecule I: CoSOO Infrared absorption: Co100 Confirmed absorption of N3 group in cPn-' Hydroxyl value: Daj, O Number of functional groups = 2 Density: /, jg/i (of the propellant of the present invention) Production and Physical Properties) Next, to 11 parts by weight of the polyether Lr, 1.06 parts by weight of trimethylolpropane (TMP) as a crosslinking agent and dibutyltin dilaure-1-0,0 as a curing catalyst were added.
/fM9 parts and the reaction product of tetraethylene entamine, acrylonitrile and glycidol as a binder (
After adding 2 parts by weight of TgpANoL) and mixing, a predetermined amount of ammonium perchlorate, which is an oxidizing agent, was added to the mixture.
The mixture was heated to 0°C and vacuum mixed for 30 minutes. Next, the curing agent hexamethylene diisocyanate (HM D
I) 10. A portion of Hiro TJ was charged and vacuum mixing was further performed for 10 minutes to obtain a slurry-like mixture. Pour this mixture into a predetermined molded container under vacuum, and after defoaming,
The propellant of the present invention was obtained by curing at 0° C. for 7 days. Regarding the slurry-like mixture immediately after vacuum mixing, Part 6
The viscosity at 0°C was measured using an Fj'l viscometer.

The binder composition and propellant distribution composition are shown in the first column, and the viscosity is shown in the second table.

In addition, the tensile characteristics and combustion characteristics were measured using the method shown below using the above-mentioned propulsion f, = ff, and the results obtained were γ? :
Shown in Table 2.

(Durability) From the propellant described above, a tensile test piece was prepared as specified by the Propellant Drugs Conference, and the tensile speed was determined! owyke.

Test 5g), a tensile test was conducted at OC and -30°C, and the maximum stress (tensile strength), strain at maximum stress (elongation), and elastic modulus were determined.

In addition, the total length of the tensile test piece specified by the Promoting Drug Properties Committee is /2! , and both ends are $ -23m, and the length between both ends! rOtym s width 10. The specimen has a thickness of io and has a central straight section.

(Combustibility characteristics) A propellant with a cylindrical shape with a diameter of q■ in the center with a diameter of 10 vrs and a length of iao was prepared, and a drug substance was created by coating the outer peripheral side with epoxy resin. did.

Load this drug trunk into a standard rocket motor chamber with an inner diameter of text, and apply pressure! The nozzle throat diameter was adjusted so that rOK, //lr/, and the specific impulse and burning speed of the propellant were measured using an ordinary small rocket motor combustion stand apparatus. Note that the aperture ratio of the nozzle is 6.

Examples 2 to 29 Polyethers represented by the general formula (1) were synthesized in the same manner as in Example 1, with the numbers of m and l being varied. Also, the amount of binder, the type and blending ratio of binder components, the type and blending ratio of dispersant, the blending ratio of combustion modifier, and the blending ratio of combustion improver? : The feminized propellant of the present invention was exploded, and the slurry viscosity, tensile properties, and combustion properties were measured in the same manner as in Example 1. The binder composition and propellant composition are shown in Table 1, and the slurry viscosity , tensile strength, and combustion properties are shown in Table 2.

In Table 1, each symbol in the binder composition and the drug composition represents the following substance.

TMP: ) Limethylolpropane HMD
I: Hexamethylene diisocyanate DB
TDL: Diptylus X dilaurate TEP'
ANOL: Tetraethylene/pentamine, acrylonitrile, and glycidol reaction product (HX-g7g, manufactured by 3M) DHE: -,) Hydroxyethyl5.
S dimethylhydantoin BTTN: /, co, daptantriol trinai trade DOA: dioctyl adipate HMX
: Cyclotetramethylenetetraethodimine RDX : Cyclotrimethylenetrinitramine, TAGN : ) Liaminoguanidine nitrate Comparative Examples 1 to 13 Using a conventional polyether represented by the general formula (II), a binder and a propellant were used. A propellant was prepared in the same manner as in Example 1 by changing the formulation composition, and the slurry viscosity, tensile strength, and aging characteristics were determined in the same manner.

The combustion characteristics were measured.

The composition is shown in Table 3, and the various measurement results are shown in Table 4.

In Examples 1 to 17 and Comparative Example 1, the binder amount was J weight i4,
The propellant contains ammonium perchlorate as an oxidizing agent in an amount of g0 weight i%. Here, in Examples 1 to 17, the elongation at a low temperature of -30°C (strain at maximum stress) was
), the elongation tends to decrease as the number of m or L in ) decreases, but when compared with Comparative Example 1, n is significantly larger, indicating that the low-temperature elongation is significantly improved in the propellant of the present invention. It is clear that In addition, the combustion characteristics are compared with n
For example, it is clear that the propellants of Examples 1 to 17 are equivalent to the propellant of Comparative Example 1, although there are some differences in size.

Furthermore, Examples 18 to 29 are propellants in which the blending composition of the binder and propellant is changed.

Comparative Examples 2 to 16 correspond to each composition.

By comparing the Examples and Comparative Examples, it can be seen that the elongation of the propellant of the present invention shown in the Examples at low temperatures at -aO°C is significantly increased compared to the Comparative Examples. it is obvious. Furthermore, it is clear that the combustion characteristics are the same in both the Examples and Comparative Examples. - that is, the propellant of the present invention does not reduce the combustion properties.

Claims (2)

[Claims] (1) In a high-energy binder type composite propellant in which the main component of the binder is a terminal hydroxyl group aliphatic polyether having a methyl azide group in the side chain, the terminal hydroxyl group aliphatic polyether has a general formula ▲ mathematical formula, chemical formula, table, etc. A high-energy binder type composite propellant, characterized in that it is represented by the following formula: (2) The high-energy binder type composite propellant according to claim 1, wherein the terminal hydroxyl group aliphatic polyether having a methyl azide group in the side chain accounts for 7 to 30% by weight of the propellant.