Joint Army/Navy Program for Environmentally Acceptable Propellant Charges for Medium Caliber Guns

WP-200529

Objective

Currently, medium caliber applications utilize propellants produced by a solvent manufacturing process. Both ball powders and stick propellants use volatile solvents throughout the production process. In the stick propellant production process, solvents are used during dehydration of the nitrocellulose (NC) (750 lbs of alcohol per 350 lbs dry weight), propellant dough mixing cycle (200 lbs of ether per 350 lbs dry weight), and deterrent coating process (150 lbs of alcohol per 900 lbs of dry weight). During a normal production cycle, approximately 3 lbs of solvent are used for every pound of propellant produced. The objective of this project is to demonstrate and validate new green NC propellants to replace medium caliber propellants containing environmentally objectionable plasticizers, stabilizers, and oxidizers.

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Technology Description

The formulation optimization effort will fabricate propellants making use of a solventless process, namely, a water slurry using an NC-based binder. A water emulsion delivery system is currently under investigation. The current design and formulation incorporates a solventless propellant formulation developed by Picatinny Arsenal, PAP-8386. The formulation is a mixture of water wet NC, NG, DEGDN, Akardit II, magnesium oxide, and DNPA. The propellant is then coated by means of an emulsion process that utilizes a polyester adipate penetrant deterrent combined with a pine resin inhibitor. The formulation contains no toxic ingredients; whereas, the solvent formulations contain diphenyl amine (DPA) and/or dibutyl phathalate (DBP), which have been identified as “environmental watch” ingredients.

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Benefits

By eliminating the solvent from the propellant process through mixing, the total overall usage of volatile solvents will be reduced by approximately 85%. Additional reductions will also be realized through the deterrent process. Legacy NC-based propellants will continue to utilize a solventless slurry process, but they will not use environmentally objectionable materials in their formulation. In addition to the environmental advantages of this formulation, Insensitive Munitions (IM) benefits also exist. Because of the solventless nature of the formulation, the propellant exhibits improved IM properties through improved mechanical properties. In the event that a catastrophic incident occurs, the ammunition will have improved reactionary responses in respect to impact. Recent gun firings have demonstrated comparable performance to the currently fielded propellant.

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Project Documents

Points of Contact

Principal Investigator

Ms. Thelma Manning

U.S. Army Armament Research, Development and Engineering Center (ARDEC)

Phone: 973-724-3015

Fax: 973-724-4708

Program Manager

Weapons Systems and Platforms

SERDP and ESTCP

Project Documents

Document Types

  • Fact Sheet - Brief project summary with links to related documents and points of contact.
  • Final Report - Comprehensive report for every completed SERDP and ESTCP project that contains all technical results.
  • Cost & Performance Report - Overview of ESTCP demonstration activities, results, and conclusions, standardized to facilitate implementation decisions.
  • Technical Report - Additional interim reports, laboratory reports, demonstration reports, and technology survey reports.
  • Guidance - Instructional information on technical topics such as protocols and user’s guides.
  • Workshop Report - Summary of workshop discussion and findings.
  • Multimedia - On demand videos, animations, and webcasts highlighting featured initiatives or technologies.
  • Model/Software - Computer programs and applications available for download.
  • Database - Digitally organized collection of data available to search and access.