A novel PMR polyimides (TMBZ-15) based on substituted benzidines is examined and compared to state-of-the-art PMR-15. The
mechanism for the thermal decomposition of two specific PMR polyimides is obtained using TG/FTIR/MS techniques. In order to
verify the pathway of polyimide degradation, a pyrolysis/GC-MS technique was employed to evaluate the organic degradation
products, particularly the larger components that are destroyed in traditional TG/MS. A proposed degradation mechanism involves
two main stages of decomposition, each of which produce a variety of products. The first group includes aromatic hydrocarbons,
aromatic amines and nitriles, which correspond to partial fragments of polymer chains. The second group consists largely of
fluorene, naphthalene and phenanthrene, which are attributed to the isomerization, rearrangements and cyclizations of the
aforementioned pyrolyzates at high temperature.