Ambient temperature mix, cast, and cure composite propellant formulations
AssigneeThiokol Corporation
InventorIngvar A. Wallace, II
Life of this patent
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Abstract
Composite propellant formulations containing a novel combination of bonding agent and cure catalyst together with carefully balanced HTPB binder and isocyanate curative may be mixed, cast, and cured at ambient temperature. The NCO/OH ratio is in the range from about 0.8 to about 0.9. The propellant formulations include as typical solid ingredients an oxidizer such as ammonium perchlorate and a reactive metal fuel such as aluminum. A plasticizer may optionally be included in the propellant to improve processing and low temperature properties. The bonding agents used in the present invention include a Schiff base or a combination of Schiff base and hydroxyl or amine functionality.
Claims19
A solid propellant formulation capable of being mixed, cast, and cured at ambient temperature comprising:
- hydroxy-terminated polybutadiene binder present in an amount ranging from about 8% to about 20% by weight;
- an isocyanate curative present in an amount ranging from about 0.7% to about 1.6% by weight, such that the NCO/OH ratio is in the range from about 0.8 to about 0.9;
- a cure catalyst;
- an oxidizer present in an amount ranging from about 50% to about 90% by weight;
- a fuel present in an amount ranging from about 0% to about 20% by weight;
- and
- a bonding agent present in an amount ranging from about 0.1% to about 0.2% by weight, said bonding agent having the following general formula:
- ##STR9## Where R.sub.1, R.sub.2, are R.sub.3 may be the same or different selected from ##STR10## --OH, --NHCH.sub.2 CH(OH)CH.sub.2 OH, --NHCH.sub.2 CH.sub.2 OH, --NH.sub.2, or --NHCH.sub.2 CH.sub.2 CN;
- and where the sum x+y+z is from about 3 to about 20.
A solid propellant formulation capable of being mixed, cast, and cured at ambient temperature comprising:
- hydroxy-terminated polybutadiene binder present in an amount ranging from about 8% to about 12% by weight;
- an isocyanate curative present in an amount ranging from about 0.7% to about 0.8% by weight, such that the NCO/OH ratio is in the range from about 0.8 to about 0.9;
- a cure catalyst;
- a plasticizer;
- ammonium perchlorate present in an amount ranging from about 60% to about 75% by weight;
- a fuel present in an amount ranging from about 10% to about 20% by weight;
- and
- a bonding agent present in an amount ranging from about 0.1% to about 0.2% by weight, said bonding agent having the following general formula:
- ##STR12## Where R.sub.1, R.sub.2, are R.sub.3 may be the same or different selected from ##STR13## --OH, --NHCH.sub.2 CH(OH)CH.sub.2 OH, --NHCH.sub.2 CH.sub.2 OH, --NH.sub.2, or --NHCH.sub.2 CH.sub.2 CN;
- and where the sum x+y+z is from about 3 to about 20.
A solid propellant formulation capable of being mixed, cast, and cured at ambient temperature comprising:
- hydroxy-terminated polybutadiene binder present in an amount ranging from about 8% to about 12% by weight;
- isophorone diisocyanate curative present in an amount ranging from about 0.7% to about 0.8% by weight, such that the NCO/OH ratio is in the range from about 0.85 to about 0.9;
- triphenyltin chloride cure catalyst;
- dioctyladipate plasticizer;
- ammonium perchlorate oxidizer present in an amount ranging from about 65% to about 70% by weight, wherein said ammonium perchlorate is present in a bimodal size distribution;
- aluminum fuel present in an amount ranging from about 15% to about 20% by weight;
- and
- a bonding agent present in an amount ranging from about 0.1% to about 3% by weight, said bonding agent having the following formula:
- ##STR15## where the sum x+y+z is from about 4 to about 8.
Dependencies are inferred from the claim text.