Real Time Analysis of Volatile Organic Compounds from Polypropylene Thermal Oxidation Using Chemical Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

The volatile organic compounds emitted during polypropylene thermal oxidation at constant temperature were analyzed in real time using proton transfer reaction associated with Fourier transform ion cyclotron resonance mass spectrometry. Four major compounds were identified: acetone, formaldehyde, acetaldehyde, and methylacrolein. The time dependence of the emissions showed a complex profile consisting successively in an induction period, a stationary state with low emission rate, and final rapid degradation of the sample. The formaldehyde mixing ratio increases by a factor of 3 between the stationary state stage and the fast degradation stage, while the other products remain in constant proportions. The kinetic and mechanistic implications of these results are discussed.