Coating Modification of Nirtramine HMX by Polymerization and Its Application

To study the coating on thenitramine HMX particle surfaces by using emulsion polymerization of HEA-AN-MA(PHMA)copolymer and isophorone diisocyanate and the effect of the coated HMX on the mechanicalproperties of the energetic composite, based on the data of coating degree from XPSmeasurements, the effect of the absorption of PHMA and the coating effect were determined.A suitable processing technique for applying the coatings was developed in an emulsionsystem. The mechanical properties were determined by the static mechanical measurementmethod. Based on the data of coating degree from XPS measurements, the method of theemulsion polymerization was superior to that of the solution polymerization in thecrosslinking of PHMA with IPDI on the surface of HMX. The optimal processing condition ofthe emulsion polymerization was the temperature 45℃, the time of reaction 120min and theamount of prepolymer between 0.15～0.20g. The sufficiently coated HMX fillers wereincorporated into an energetic composite. An increase of the tensile strength wasobtained. It is shown that forming a crosslinked polymeric coating on HMX particlesurfaces plays a role for interfacial reinforcement between HMX fillers and polymericbinders.