Burn Rate Modifier for Propellants

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Solution Overview

Problem

Current burn rate modifiers like dinitrotoluene (DNT) and dibutyl phthalate are toxic, carcinogenic, and face regulatory bans due to environmental concerns, necessitating a safer alternative for propellants in ammunition.

Innovation Solution

Development of 4-(4-hydroxyphenyl)butan-2-one and its derivatives as a burn rate modifier, which exhibit superior burn rate modification properties without toxicity or carcinogenicity, suitable for use in propellants and ammunition cartridges.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If dinitrotoluene (DNT) is used as a burn rate modifier, then burn rate regulation is achieved, but toxicity and carcinogenicity increase

Engineering Contradiction:
Improveburn rate regulationVSAvoidtoxicity and carcinogenicity
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies parameter changes by modifying the chemical structure of traditional burn rate modifiers. Specifically, it uses compounds with formula (I) where R1-R6 represent various substituent groups (hydrogen, halogen, alkyl, alkoxy, nitro, cyano, etc.), allowing systematic variation of chemical parameters to achieve effective burn rate control while eliminating the toxic and carcinogenic properties of DNT.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention employs composite materials by combining the base propellant (containing nitrocellulose and other energetic materials) with coating compositions that contain the new burn rate modifier compounds. The coating composition may include solvents, plasticizers, and the formula (I) compounds, creating a composite structure that provides both burn rate control and improved safety profile.

Inventive Principle:
Principle #40Composite materials

2Reliability

If dibutyl phthalate (DBP) is used as a burn rate modifier, then burn rate control is achieved, but environmental restrictions increase

Engineering Contradiction:
Improveburn rate controlVSAvoidenvironmental impact
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies parameter changes by replacing DBP with compounds of formula (I) that have different chemical and environmental properties. The substituent variations in formula (I) allow optimization of environmental compatibility while maintaining burn rate control functionality, addressing the environmental restrictions placed on phthalates.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If traditional burn rate modifiers are used, then burn rate modification is achieved, but chemical stability decreases

Engineering Contradiction:
Improveburn rate modificationVSAvoidchemical stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The invention uses parameter changes in the molecular structure of burn rate modifiers (formula (I) compounds with various R1-R6 substituents) to achieve both effective burn rate modification and improved chemical stability. The specific substituent patterns are selected to enhance compatibility with nitrocellulose and other propellant components, reducing degradation and improving long-term stability.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The new burn rate modifier demonstrates improved stability and performance, offering enhanced ballistic consistency and thermal stability, making it a suitable substitute for DNT with reduced environmental impact.

Implementation Method 1

Burn deterrents that function by interrupting the chain reaction of burning do so by stabilising free radicals. This stabilisation extends the lifetime of the radicals, slows the rate of the radical processes and subsequently, there is less, or slower, combustion.

Methodology Applied
Scientific EffectFree radical stabilization:

Implementation Method 2

The chemical can penetrate to some extent into the grain matrix and acts to slow the burning reaction

Methodology Applied
Scientific EffectPenetration and absorption: Absorption (physical)

Data Source

PatentEP3044191B1Burn rate modifier
Publication Date: 2019.11.20 THALES AUSTRALIA LTD
  • EP3044191B1 patent drawingFigure 1~2
  • EP3044191B1 patent drawingFigure 3~4
  • EP3044191B1 patent drawingFigure 5~6

AI summary

The invention relates generally to burn rate modifiers and propellants comprising a burn rate modifier. The invention also relates to methods of producing a propellant comprising a burn rate modifier as well as an ammunition cartridge comprising the propellant. The burn rate modifier comprises a compound of formula 1and the propellant comprises a compound of formula 1 and an energetic material.