Novel Energetic Polyphosphazene Polymer Binder System for Environmentally Benign Rocket Propellants
WP-2141
Objective
Solid rocket motor propellants and explosives utilized within the Department of Defense (DoD) historically have been formulated to provide the most performance over all other operational requirements including environmental and sensitivity considerations. The current fielded minimum signature rocket propellants incorporate burn rate catalysts (primarily lead compounds) and RDX, a nitramine, to achieve burning rate and performance objectives. Both lead and RDX are toxic to humans, and RDX can react strongly to outside stimuli and be hazardous.
The objective of this project is to develop the next generation of environmentally benign propellants for use in weapons systems by introducing cutting edge energetic materials as replacements for toxic lead catalysts and RDX explosives. The resultant propellants should meet key performance parameters and an improved level of insensitivity to unwanted initiation.
Technical Approach
This limited-scope project will investigate the viability of developing a new class of minimum signature propellants utilizing nitrato/azido functionalized polyphosphazene that provide an energetically dense polymer backbone with superior low-temperature properties compared to existing energetic polymers. The application of a polyphosphazene energetic (PPZ-E) polymer system with a polymer backbone that contains higher enthalpy functional groups (-ONO2, -N3) will allow reaction kinetics and heats of combustion to control burn rate parameters rather than catalytic kinetics, thus eliminating the need for lead or any other metal burn rate modifiers. Similarly, RDX nitramine content will be replaced with more thermodynamically stable energetics--diamino dinitroethylene (FOX-7), guanylurea dinitramide (FOX-12), or similar ingredients stabilized by hydrogen bonding, overlapping Pi orbitals, and resonance structures--that respond more favorably to various stimuli.
Benefits
A working knowledge of the ability of polyphosphazenes to act as new polymer replacements in minimum signature propellants without undue secondary smoke will be achieved and a tool-kit of ingredients identified from which to choose that exhibit less toxicity and sensitivity. The resulting robust low-temperature energetic polymer system will be applicable for minimum signature fixed wing environments. An energetic polymer/oxidizer system could also serve as a possible replacement for HTPB-HTCE and ammonium perchlorate-based propellants that exhibit high levels of perchlorate contaminants. (Anticipated Project Completion - 2012)
Points of Contact
Principal Investigator
Mr. Joseph Clubb
Naval Air Warfare Center - Weapons Division
Phone: 760-939-7661
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.