Fabrication of molded block of dilute high explosive foamed polyurethane

Abstract

A process, apparatus, and composition are disclosed for forming a molded foamed polyurethane explosive block with pentaerythritol tetranitrate in a manner in which the generation of excessive exothermic heat is inhibited during the reaction to form the foamed polyurethane. In one aspect of the invention, the exothermic heat generation is controlled by the use of non-reactive filler materials. In a preferred embodiment, a monoammonium phosphate filler is used to further impart fire retardant properties to the resultant molded foam explosive block. In another aspect of the invention, the reactants are introduced into a mixing chamber by remote control, wherein the mold itself forms a bottom wall of the mixing chamber, and the remainder of the mixing chamber is portable and is removed from the mold, after the reactants used to form the foamed polyurethane and the pentaerythritol tetranitrate explosive have been mixed together, to thereby eliminate the need to transfer the mixture from a mixing chamber into a mold while the thermosetting reactants are reacting to form the foamed polyurethane.