FT‐IR study of the stabilization reaction of polyacrylonitrile in the production of carbon fibers

Abstract
The stabilized fibers prepared by heating PAN and a PAN copolymer in air and under reduced pressure have been examined by FT‐IR spectroscopy in order to determine their chemical structures. Three kinds of reactions, cyclization, dehydrogenation, and oxygen uptake are found to occur almost simultaneously in the stabilization process in air by digital difference spectrum method. The effect of the comonomer is confirmed to accelate the dehydrogenation reaction and also the formation of acridone ring in the thermal stabilization in air by kinetic study.