Thermal degradation of polyurethanes investigated by direct pyrolysis in the mass spectrometer

Direct pyrolysis in the mass spectrometer yielded evidence on the mechanisms of thermal decomposition of N-monosubstituted and N-disubstituted polyurethanes. Our results indicate that N-monosubstituted polyurethanes undergo quantitatively a depolycondensation process, producing diisocyanate and diol. In contrast, disubstituted polyurethanes decompose to give selectively secondary amine, olefine and CO₂.