Low pressure exponent propellants containing boron

Abstract

Propellant grain consisting essentially of: A. from about 50% to about 75% by weight of an oxidizer consisting essentially of ammonium nitrate; B. from about 1% to about 20% by weight of a cured polymeric binder; C. from 0% to about 30% by weight of a nitrate ester plasticizer; D. from about 3.5% to about 8% by weight of boron in free elemental form; and E. from 0% to about 3% by weight of aluminum metal. The grain has a pressure exponent not exceeding about 0.30 at a combustion pressure between about 2500 and about 7000 pounds per square inch (between about 1700 and about 4800 N/cm.sup.2). Also, an uncured pourable slurry having the formula stated above, except that the binder is uncured. Also, a method for forming a propellant grain having the formula stated above, comprising the steps of providing the uncured pourable slurry defined above, pouring the slurry into a casing, and curing the slurry in situ to form a cured propellant grain having a pressure exponent not exceeding about 0.30 in the pressure range defined above.

Dependencies are inferred from the claim text.