Dagobert E. Stuetz

Production of activated carbon fibers from acid contacted polybenzimidazole fibrous material

An improved process which makes possible the expeditious formation of activated carbon fibers having high absorptivity characteristics is provided. A polybenzimidazole fibrous material is contacted with a solution of an acid (e.g. sulfuric acid) so as to form a polybenzimidazonium salt (as described), and the resulting fibrous material is preoxidized, carbonized, and activated under the conditions defined which have been found to reliably and expeditiously yield the desired product. The resulting activated carbon fiber product exhibits a dynamic weight absorptivity of at least 100 mg. of CCl4 per gram, and particularly is suited for the formation of protective garments having highly satisfactory sorptive characteristics.