Abstract
The effect of impurities on the thermal degradation of poly-[ N, N′-( p, p′-oxydiphenylene) pyromellitimide] (du Pont's ‘H’-film) is discussed. Purification of the polymer in dimethylformamide decreases the rates of degradation both in air and in vacuum, but only slightly reduces the activation energies. Infrared and mass spectrometric data suggest the participation of polypyromellitamic acid (poly armmide acid) impurity in the degradation process by thermal cleavage of its carboxyl and hydrolytic scission of its amide groups. As far as the vacuum pyrolysis of the main poly imide chains is concerned, the activation energy of 74 kcal/mole, bond dissociation energies, and elemental analysis of the residue remaining after pyrolysis suggest that the primary scission occurs at the imide bonds, most likely followed by a secondary cleavage resulting in the elimination of CO groups.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.