Preparation of carbon fibers from biomass-based phenol-formaldehyde resin

The work was carried out to get information how to use wasted biomass, particularly waste woods, as a raw material for fine and advanced carbon products. A phenol-starch-formaldehyde resin was synthesized by using phenol of which one third was replaced by cornstarch as a model material for waste wood. The resin was spun, stabilized and finally carbonized at 900◦C. A commercial novolac-type phenol-formaldehyde resin was used as a reference. There was no essential difference in the microscopic structures between the carbon fibers derived from the synthesized and the commercial resins, but the former resin showed some disadvantages against the latter: one is a poor spinnability to result in thick and irregular carbon fibers, and another one is the formation of macropores in the resulting carbon fibers, leading to low mechanical strength. These disadvantages are thought to be caused by the remaining MgO particles used as a neutralization agent in the synthesis of the resin. A possibility to achieve the final purpose is discussed briefly. C 2005 Springer Science + Business Media, Inc.