Ozone degradation study of novel chain extended energetic polymers containing carbon-carbon double bonds

A range of chemically modified energetic polymers has been synthesized. The structural modification involves the incorporation of a double bond into t he polymeric binder which allows subsequent degradation of the material by ozonolysis thus providing an environmentally safe method for the disposal o f munitions. This was achieved by reacting the energetic prepolymer, poly-N IMMO, with a range of unsaturated diisocyanates where the double bond was i ncorporated into the cross-linking i.e. "curing" agent. Firstly, poly-NIMMO and cis-1,4-but-2-ene diol were reacted with hexamethylene diisocyanate. S econdly, three unsaturated diisocyanates (two novel) were prepared in situ from their corresponding diacyl azides and reacted with poly-NIMMO. The thr ee diisocyanates prepared were 1,4-diphenoxy-trans-2-butene-diisocyanate, p henylene diacrylic diisocyanate, and trans-2-butene-1,4-diisocyanate. The l atter has been reported previously((1,2)) although never isolated and chara cterized; however, this has been achieved successfully in this study. GPC o f the chain extended polymers prepared by both methods showed the expected increase in molecular weight distribution. A corresponding decrease followi ng ozonolysis occurred particularly with the polymers prepared from 1,4-dip henoxy-trans-2-butene-diisocyanate and phenylene diacrylic diisocyanate.