Use of carbon fibrils to enhance burn rate of pyrotechnics and gas generants
AssigneeThiokol Corporation
InventorsDaniel B. Nielson, Dean M. Lester
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AssigneeThiokol Corporation
InventorsDaniel B. Nielson, Dean M. Lester
Estimating the term…
Conductive carbon fibrils are incorporated into energetic compositions to enhance the burn rate. The carbon fibrils are grown catalytically from carbon precursors and are substantially free of pyrolytically deposited thermal carbon. The fibrils generally have a length in the range from about 1.mu. to about 10.mu. and a diameter in the range from about 3.5 nanometers to about 75 nanometers. Length to diameter aspect ratios are greater than 5, and typically in the range from about 100:1 to about 1000:1. A 100% improvement in burn rate was observed in compositions containing as little as 0.1 weight percent carbon fibrils. Greater amounts of carbon fibrils (2 weight percent) have increased the burn rate 500%. In most cases, fibril concentration will be in the range from about 0.1 to about 2 weight percent, although greater amounts are possible. The burn rate may be effectively tailored by varying the amount of fibrils added to the composition.
A method for enhancing the burn rate in an energetic composition selected from propellant and pyrotechnic energetic compositions comprising incorporating into said energetic composition an effective quantity of conductive carbon fibrils sufficient to increase the burn rate at least 20% upon burning said energetic composition, said carbon fibrils having substantially continuous layers of ordered carbon atoms having an outside diameter between about 3.5 and 75 nanometers which are catalytically grown and having a distinct inner core region, each of the carbon layers being disposed substantially concentrically about the inner core region, wherein the fibrils are substantially free of pyrolytically deposited thermal carbon.
A method for enhancing the burn rate in propellants and pyrotechnics compositions comprising the steps of:
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