Nitro-substituted diisocyanate compounds

摘要

Nitrated polyurethanes suitable as propellants are prepared by reacting hexanitro diisocyanates of the formula:- wherein A and A1 are C1-3 alkylene radicals, with glycols such as 2,2-dinitro-1,3-propanediol, 2,2,4,4-tetranitro-1,5-pentanediol, or 2-nitro-2-methyl-1,3-propanediol.ALSO:The invention comprises hexanitro diisocyanates of the formula:- wherein A and A1 are C1-3 alkylene radicals. Th compounds are prepared by heating a diacid halide of the formula:- (where X represents halogen, e.g. chlorine or bromine) with an alkali or alkaline earth metal halide to form a diacid azide of the formula:- which is then heated to effect rearrangement to the required diisocyanate. Diacid halides of the above formula are obtained by treating the corresponding dicarboxylic acids with PCl3, PCl5 or PBr5.