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Structural determination of pyrolyzed PI‐2525 polyimide thin films
Author(s) -
Hu C. Z.,
Andrade J. D.,
Dryden P.
Publication year - 1988
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1988.070350502
Subject(s) - polyimide , pyrolysis , materials science , carbonization , amorphous solid , x ray photoelectron spectroscopy , carbon fibers , chemical engineering , amorphous carbon , graphite , composite material , polymer chemistry , organic chemistry , chemistry , scanning electron microscope , layer (electronics) , composite number , engineering
Polyimide was pyrolyzed in an argon atmosphere at various temperatures, and thermally converted to amorphous carbon films. The irreversible change of polyimide under progressive heat treatment is characterized by three successive structural changes: pyrolysis, carbonization, and graphitization. X‐ray photoelectron spectroscopy (XPS) studies show that the polyimide starts to dissociate at pyrolysis temperatures above 500°C. At temperatures higher than 650°C most functional groups of polyimide decompose to evolve gases from the sample. The polyimide then gradually becomes more carbon rich. It is believed that at pyrolysis temperature higher than 650°C the polyimide starts to form heterocyclic structures with residual oxygen and nitrogen incorporated into the heterocyclic carbon rings. X‐ray analyses indicate that the polyimide at pyrolysis temperatures less than 1000°C is amorphous carbon and no long‐term periodic structure can be detected. At pyrolysis temperatures higher than 2000°C, the polyimide is converted to microcrystalline graphite.