Investigation of the thermal degradation of alkyl isocyanate polymers by direct pyrolysis mass spectrometry

Thermal degradation mechanisms of alkyl isocyanate homo- and copolymers were studied using TGA and DP–MS. Both analyses showed that these polymers begin decomposing at around 190°C under inert or vacuum conditions. DP–MS analysis showed the formation of trace quantities of monomer from poly(butyl isocyanate) only and none from higher homologs. All polymers studied produced trimers as their principal decomposition product, implying that intramolecular cyclization is the dominant mechanism of decomposition.