Abstract Dynamic mechanical analysis is combined with mass spectrometry to study nitrocellulose and nitrocellulose–diphenylamine films under oscillating strain. At a constant temperature (150–160 °C) and frequency 400–600 Hz nitrocellulose fractures demonstrating a modulus drop and release of products with m / z = 30 and 44. At a linear heating (2 °C min −1 ) and frequency 10–50 Hz similar products are released in two steps, the second of which demonstrates a modulus drop and a temperature increase indicating ignition. Addition of 2 mass% of diphenylamine markedly enhances the resistance of nitrocellulose to mechanochemical degradation. At 160 °C, the process has been initiated only after significant exposure times to high frequencies: 67 min at 200 Hz, 36 min at 300 Hz and 29 min at 400 Hz.