Preliminary Investigation of the Degradation and Stabilisation of the EnergeticOxetane Binder Polynimmo

摘要

Information on the structure and functionality of poly(3-Nitratomethyl-3-methyloxetrane), polyNIMMO, is presented and the properties of binders cured with the isocyanate Desmodur N-100 are considered. Results from the ageing of crosslinked polyNIMMO are presented and the effects of adding the stabilizer 2 nitrodiphenylamine, (2NDPA), are demonstrated. It is shown that decomposition of the nitrate ester groups of unstabilized polyNIMMO is a major process but the rate of this process is much lower than that observed for nitroglycerin. Decomposition of the nitrate ester groups in polyNIMMO is accompanied by chain scission of the polyether backbone. Two effects were observed as a result of adding 1 percent of 2NDPA: the rate of nitrate ester breakdown was significantly reduced, and the rate of polymer chain scission was greatly retarded. Results indicate that chain scission only becomes significant when the stabilizer has been consumed. Current results show that the stabilized binder still retains its network structure after one year at 60 C.