Direct mass spectrometry of polymers. XII. Thermal fragmentation processes in poly‐α‐aminoacids

The thermal fragmentation processes in poly‐α‐aminoacids have been investigated by direct pyrolysis–Mass Spectrometry. The mass spectral data show that the pyrolytic breakdown of polyglycine, polysarcosine, and polyproline leads to the formation of cyclic oligomers. Polyalanine, polyphenylalanine, and polytyrosine decompose yielding compounds with olefin and nitrile end‐groups. Finally, in the case of poly‐α‐methylglutamate, the primary thermal process is the loss of methanol with consequent formation, along the polymer chain, of pyroglutamic units, which yield cyclic dimer as main pyrolysis product.