Effects of Comonomer and Two-step Oxidation on Production of Polyacrylonitrile-based Carbon Fibers

Abstract

Oxidation conditions of precursor polyacrylonitrile (PAN) fibers govern not only the performance but also productivity of PAN-based carbon fibers. The effect of the incorporation of 2 wt% of comonomers, such as Sodium acrylate (SA), methyl acrylate (MA), acrylamide (AAm) and 2-hydroxyethyl acrylate (HEA) to PAN on the productivity of carbon fibers was investigated. DSC, ch emically-bound oxygen and formation of skin-core structure in oxidized fibers, and also carbon yield and tensile strength of carbonized fibers were measured. In order to get the high performance carbon fibers with high productivity, in other words, in short oxidation time, it was found that the precursor PAN fibers containing SA had to be oxidized in 2 steps; oxidation at 243°C, the maximum temperature not giving skin-core structure in the fiber, up to the chemically-bound oxygen content of about 5 % and then oxidation at 275°C up to the DSC exothermic calorie of about 10 cal/g or the total oxygen content of about 12%.