Microporous texture of activated carbon fibers prepared from aramid fiber pulp

Kevlar^® (poly(p-phenylene terephthalamide), PPD-T) pulp was used for the first time as a feedstock to prepare activated carbon fibers (ACFs). These were obtained by pyrolysis to 1173 K under inert (Ar) atmosphere and subsequent activation with carbon dioxide at two different temperatures (1023 and 1073 K). The resulting ACFs were characterized by adsorption of N₂ (77 K) and CO₂ (273 K). The surface area and pore volume increased after pyrolysis and especially after CO₂ activation, reaching maxima around 60% burn-off. It is concluded that Kevlar pulp constitutes a suitable feedstock for preparing microporous ACFs having a narrow pore size distribution, which is closely associated with the crystalline character of the precursor.