agent for the polymeric binder will of course depend upon the particular polymeric binder employed in the case of hydroxy terminated polybutadiene binders the curing agents usually employed are di or polyisocyanates examples of such curing agents may be found in u s pat no 4 184 031 issued jan 15 1980 to graham et al which is hereby incorporated by reference a commonly employed example of these isocyanates is isophorone diisocyanate ipdi the metallic fuel and ammonium salt oxidizer most commonly used in composite propellants are powdered aluminium and ammonium perchlorate respectively although other metallic fuels and ammonium salt oxidizers known in the art may likewise be employed the composite propellant formulations useful in the practice of this invention may of course contain other ingredients in addition to those discussed above thus plasticizers fillers reinforcing agents burn rate modifiers and the like may be used one additive which has been found to be particularly useful in the practice of this invention is an alkyl monoisocyanate such as the c 10 c 25 alkyl monoisocyanates an example of which is octadecyl isocyanate odi it has been found that the addition of odi to the propellant reduces the viscosity of the propellant and thereby aids processing the amount of odi employed will vary depending upon the viscosity of the propellant mix and in fact may not be necessary at all if the viscosity of the mix is already sufficiently low in general however the alkyl monoisocyanate is employed in an amount sufficient to reduce the viscosity of the propellant mix but not so much as to affect the strain properties of the final cured propellant normally this amount will be about 0 01 to 0 10 based.