Methods for producing carbon fibers from versatile commercial fibers

摘要

The method for producing carbon fibers comprises providing a polyacrylonitrile precursor polymer fiber filament. The polyacrylonitrile precursor filament contains 87 to 97 mole percent of acrylonitrile and less than 0.5 mole percent of the promoting functionality. The filament is 3 denier or less per filament. The polyacrylonitrile precursor fiber filament may be arranged in a tow at least 150,000 denier per inch width. The arrayed polyacrylonitrile precursor fiber tow comprises at least one oxidation zone containing oxygen gas and maintained at a first temperature (T ₁ ) while stretching the tow by at least 10% to obtain a stabilized precursor fiber tow The tow is stabilized by heating. The stabilized precursor fiber tow is carbonized by passing the stabilized precursor fiber tow through a carbonization zone. Carbon fibers produced by this process are also disclosed.