Abstract
In recent decades carbon fibers have been used widely from various purposes. However, the practical utilization of carbon fiber is limited by its high price which comes from the high cost of its feedstock as well as manufacturing cost. We have proposed a degradative solvent extraction method to separate various low-rank coals and biomasses to several fractions under mild conditions. The low-molecular-weight fractions, obtained in around 30 % yield, can soften and melt completely at around 100℃. In this study, the low-molecular-weight fractions were proposed to be used as low-cost precursors for the carbon fiber. Preliminary experiments showed that the fractions can be easily spun to prepare spun fibers. The spun fibers were then extracted by cyclohexane to remove light compounds and stabilized by thermal treatment from 50℃ to 330℃ in air in 10 hours. The carbonization was performed at 1000℃ for 1 hour in N2. The diameter of the carbon fiber obtained was around 5 μm. Thus, the low-molecular-weight fractions obtained by low-rank coal or biomass extraction can be promising precursors of low cost carbon fiber.
