RU2229465C1 - Stabilizer of chemical resistance of nitrocellulose blasting powders and solid rocket propellants and a method of their treatment - Google Patents

Abstract

FIELD: chemical industry; production a stabilizer of chemical resistance of nitrocellulose blasting powders and solid rocket propellants. SUBSTANCE: the invention presents a stabilizer of chemical resistance of blasting powders and solid rocket propellants and a method of their treatment. The invention is dealt with chemical industry, in particular with production and application of the stabilizer of nitrocellulose blasting powders and solid rocket propellants used in the barreled and rocket-propelled systems. The offered stabilizer of chemical resistance of nitrocellulose blasting powders and solid rocket propellant is a compound of tetramethylpiperidine being 2.2.6.6-tetramethyl-4-oxopiperidine or 2.2.6.6-tetramethyl-4- hydroxypiperidine or 2.2.6.6-tetramethy-4- hydroxypiperidine -1-oxyl. The invention also offers a method of treatment of nitrocellulose blasting powder and solid rocket propellant with application of the indicated stabilizers of chemical resistance. Introduction of the indicated compounds into composition of nitrocellulose blasting powders or solid rocket propellants in amount of 0.1-10 % of their mass ensures required chemical resistance of nitrocellulose blasting powders without transmutation of the used indicated compounds into toxic products. At that the invention allows to achieve an increase of a flame-extinguishing factor and ballistic characteristics. Besides utilization of the indicated compounds of tetramethylpiperidines family in treatment of nitrocellulose blasting powders and solid rocket propellants ensures their advanced light- and thermal resistance and promotes inhibition of radical oxidation and improvement of ecology. EFFECT: the invention ensures achievement of the required chemical resistance of nitrocellulose blasting powders and solid rocket-propellants without their transformation in toxic elements, improvement of their flame-extinguishing factor, ballistic characteristics and safe ecology. 2 cl, 3 ex

Description

The invention relates to the field of nitrocellulose powders and solid rocket fuels, which are used in barrel and rocket systems.

It is known that currently, for the treatment of nitrocellulose powders and solid rocket fuels, stabilizers N-nitrosodiphenylamine, alkylated diphenylureas (centrolites) or diphenylamine are used in concentrations of 0.2-4 wt.% (RU 2093500 C1, 1997; RU 2026276 C1, 1995 ; RU 2198870 C2, 2003; US 391776, 1975).

As the closest analogue of this group of inventions, the diphenylamine stabilizer of chemical resistance of nitrocellulose powders and diphenylamine can be used to stabilize the chemical resistance of nitrocellulose powders [Brief Encyclopedic Dictionary. Condensed energy systems. M .: Janus-K, 2000, pp. 407-408].

A disadvantage of the known stabilizers of nitrocellulose powders and solid rocket fuels is that currently used as stabilizers N-nitrosodiphenylamine, centrolites and diphenylamine in the process of obtaining, storage, use, processing and disposal of nitrocellulose-containing (pyroxylin-containing) materials, gunpowders form toxic substances, and these stabilizers themselves belong to different hazard classes (Harmful substances in industry. Edited by N.V. Lazarev. L .: Chemistry, 1969). In addition, the disadvantage of the known stabilizers of nitrocellulose powders is their limited range, which does not allow to obtain a variety of composite materials, gunpowder, solid rocket fuels, with desired properties without introducing additional components.

The objective of the present invention is to improve the quality of nitrocellulose-containing materials, as well as their properties and ecology in the process of obtaining, storage, use, processing and disposal due to the universality of the properties of the introduced substances, which simplify their composition, as well as to obtain composition formulations, gunpowders and solid rocket fuels with desired properties while increasing the range of substances used to stabilize nitrocellulose powders and solid rocket fuels.

The solution to this problem is achieved by using as a stabilizer nitrocellulose powders and solid rocket fuels compounds of a number of tetramethylpiperidines of the general formula

where at R ₁ = O, R = H it is 2,2,6,6-tetramethyl-4-oxopiperidine;

when R ₁ = OH, R = H, it is 2,2,6,6-tetramethyl-4-hydroxypiperidine;

when R ₁ = OH; R = O, it is 2,2,6,6-tetramethyl-4-hydroxypiperidin-1-oxyl.

A method for treating nitrocellulose vices and solid rocket fuels using a stabilizer - tetramethylpiperidine compounds of the above formula in an amount of 0.1-10.0% by weight of the processed material is also proposed.

It is known to use tetramethylpiperidine compounds as light and heat stabilizers for polymeric materials subjected to degradation, in particular polyester, polyolefin, acrylonitrile resins and varnishes, as well as rubbers (RU 2036921 C1, 1995), for stabilization of anaerobic sealing composition (RU 1455686 A1, 1995) , as a reagent for determining oxygen in the field of adsorption, catalysis, physical chemistry of the surface of solids (RU 1792913 A1, 1993), upon receipt of optical fibers (RU 2171319 C2, 2001), for the purification of hydrocarbons from cyclopentadiene (RU 835085 A1, 2000), to stabilize from hydrolysis of organic phosphites and phosphonites used as thermostabilizers of polymers (RU 2126011 C1, 1999), to control the presence of liquid microphases in the manufacture of tanned leather (RU 2008362 C1, 1994), as an inhibitor of the polymerization of methyl methacrylate (RU 1342279 C, 1994).

However, the use of these compounds as a stabilizer of nitrocellulose powders and solid rocket fuels is new, not known from the prior art.

New and non-obvious is the establishment that the use of these compounds in the processing of nitrocellulose powders and solid rocket fuels in an amount of 0.1-10% of their mass provides the required chemical resistance, while no toxic conversion products of the indicated compounds were found.

The following examples illustrate but do not limit the present invention. In all examples, the samples were prepared according to the well-known classical technology.

Example 1

In 50 ml of ethyl acetate (EA) dissolve a weighed stabilizer of 2,2,6,6-tetramethyl-4-oxopiperidine in an amount of 0.4% by weight of pyroxylin taken with an accuracy of 0.0001 g, then 5 g of pyroxylin with a nitrogen content of less than 212.0 ml NO / g (taking into account humidity = 57.3 wt.%). The resulting mixture is periodically stirred for 24-28 hours until a homogeneous mass is formed. The mass is poured over the surface of the mold to a film and dried. The obtained nitrocellulose film is cut into samples and their chemical resistance is determined according to OST B 84-2085-92.

Under the conditions of example 1, 1.5% by weight of pyroxylin 2,2,6,6-tetramethyl-4-hydroxypiperidin-1-oxyl was used and the chemical resistance of the samples was determined according to OST B 84-2085-92.

Example 2

In 50 ml of ethyl acetate (EA) dissolve a weighed stabilizer of 2,2,6,6-tetramethyl-4-hydroxypiperidine in an amount of 5.0% by weight of ballistite, taken with an accuracy of 0.0001 g, then 5 g of ballistite are poured. The resulting mixture is periodically stirred for 24-28 hours until a homogeneous mass is formed. The mass is poured over the surface of the mold to a film and dried. The obtained nitrocellulose film is cut into samples and their chemical resistance is determined according to OST B 84-2085-92.

Example 3

In 50 ml of ethyl acetate (EA) dissolve a portion of the stabilizer 2,2,6,6-tetramethyl-4-hydroxypiperidin-1-oxyl in an amount of 3.5% by weight of cordite taken with an accuracy of 0.0001 g, then 5 g of cordite is poured . The resulting mixture is periodically stirred for 24-28 hours until a homogeneous mass is formed. The mass is poured over the surface of the mold to a film and dried. The obtained nitrocellulose film is cut into samples and their chemical resistance is determined according to OST B 84-2085-92.

In the conditions of example 3 use 1.0% by weight of cordite 2,2,6,6-tetramethyl-4-oxopiperidine and determine the chemical resistance of the samples according to OST B 84-2085-92.

The chemical resistance of the obtained samples was determined according to OST B 84-2085-92 (Monometric method for determining the resistance of all types of gunpowder).

As a result of the tests, the effectiveness of the stabilizers was shown when they were introduced into the samples in an amount of 0.1-10% by weight, while the required stability of the compositions was achieved with an increase in the flame retardation rate and ballistic characteristics. In addition, the use of these compounds of a number of tetramethylpiperidines in the treatment of nitrocellulose powders and solid rocket fuels provides their increased light and heat resistance, and also helps to inhibit radical processes while improving the environment.

Claims (2)

1. The stabilizer of chemical resistance of nitrocellulose powder and solid rocket fuel, which is a compound of tetramethylpiperidine of the General formula

where at R ₁ = O, R = H it is 2,2,6,6-tetramethyl-4-oxopiperidine, with R ₁ = OH, R = H it is 2,2,6,6-tetramethyl-4-hydroxypiperidine when R ₁ = OH, R = O it is 2,2,6,6-tetramethyl-4-hydroxypiperidin-1-oxyl. 2. A method of processing nitrocellulose powder and solid rocket fuel using a chemical stability stabilizer, characterized in that as a chemical stability stabilizer, a chemical resistance stabilizer according to claim 1 is used in an amount of 0.1-10.0% by weight of the processed nitrocellulose powder and solid rocket fuel.