Abstract: 1. In the process for preparing a rocket motor, the improvement which comprises applying a layer of an uncured organic material capable of being cured to a rubbery material, to the interior combustion chamber wall of a rocket vessel, partially embedding powder grains in the exposed surface of said uncured material before solidification, thereafter curing and solidifying said uncured material, whereby a rubber-base liner is formed having one surface firmly adhering to said wall and said powder grains firmly adhering to the exposed surfaces of said liner, with a portion of each powder grain protruding from said liner, filling the lined portion of the chamber with a thermoplastic propellant charge, and solidifying said propellant charge, whereby a firmly adhering bond is formed between the solidified propellant charge, the powder grains and the solidified liner.

Abstract: 1. In combination with a vessel forming a rocket motor combustion chamber, a rubber-base liner firmly adhering to the interior chamber wall, said rubber-base liner containing between about 2.5 and 30 percent by weight of an inorganic metal salt selected from the group consisting of zinc chromate, barium chromate, zinc phosphate, lead phosphate, potassium phosphate, and mixtures thereof, and a propellant charge substantially filling the lined portion of the chamber, said propellant charge firmly adhering to said liner.

Abstract: 1. In combination with a vessel forming a rocket motor combustion chamber, a rubber-base liner having one surface firmly adhering to the chamber, the opposite surface of said rubber-base liner having a plurality of discrete powder grains partially embedded therein, each of said powder grains having a portion extending from said opposite surface of said rubber-base liner, and a propellant charge substantially filling the lined portion of said chamber, said propellant charge firmly adhering to said liner and enveloping each of said extending portions of said powder grains.

Abstract: 1. A composition for lining the combustion chamber of a rocket motor employing a solid propellant comprised of an epoxy resin, a copolymer of butadiene and acrylic acid, a curing agent, and between about 2.5 and about 30 per cent by weight of an inert inorganic filler selected from the group consisting of carbon, ferric oxide, titanium dioxide and mixtures thereof.

Abstract: 1. A composition of matter comprised of an epoxy resin, a copolymer of butadiene and acrylic acid, a curing agent, and between about 2.5 and about 30 percent by weight of an inorganic metal salt selected from the group consisting of metal chromates, metal bichromates, metal phosphates, and mixtures thereof.