Study on the spontaneous ignition mechanism of nitric esters (II)

The thermal behavior of cellulose nitrate (NC) with diphenyl amine (DPA) or a phenol-based oxidation inhibitor (AO80) was investigated in order to estimate the effect as a stabilizer in a smokeless powder. During the isothermal storage at 393 K, both stabilizers decreased the amount of the reaction heat of NC, and lengthened the induction period of the exothermic reaction. Those effects might indicate that both stabilizers were capable of suppressing the spontaneous ignition. However, the effects of DPA and AO80 on the isothermal storage of NC were different. Under the storage in O2, DPA showed larger effect on the induction period but less effect on the released heat reduction than AO80 did. Those differences might be understood as follows: DPA mainly prevented the reaction before the autoxidation by trapping NO2, while AO80 mainly prevented the autoxidation of NC by trapping ROO.