High Modulus Carbon Fiber Processes

Abstract

Although carbon fibers have been made inadvertently from natural fibers for thousands of years, it was Edison (1) in 1878, who purposely took cotton fibers, and later bamboo, to make carbon lamp filaments. Interest in carbon fibers was renewed in the late 1950's, when synthetic cellulosics (rayons) in textile forms were converted to carbon fibers. Although other precursor fibers were studied, cellulosics remained the main source for carbon fibers until the mid 1960's. All these fibers had low stiffness, although some obscure reports and related technology indicated that high modulus carbon fibers could be made. In early 1964, Bacon (2) made the first high modulus carbon fiber by hot stretching rayon precursor carbon fibers. This was followed by Watt (3), who made a high modulus carbon fiber by retaining some of the original preferred orientation of polyacrylonitrile in the carbon fiber. Although other fiber types have been investigated for precursors,