Biodegradation of pitch-based high performance carbon fibers.

Abstract

Biodegradation of pitch-based high performance carbon fibers (HPCF) by microorganisms was studied. The degraded fiber was examined by scanning electron microscopy. Aspergillus flavus ruptured surface areas of HPCF (carbon type, prepared by heat treatment at 1000°C) in 60 days. The fibril structure under the surface layer of the fiber was exfoliated by degradation. The fibrils on the second layer were 100-110 nm wide. The fibrils were oriented nearly parallel to the fiber axis. HPCF (graphite tiye, prepared by heat treatment at 2000°C) did not exhibit ruptured areas like HPCF (carbon), showing greater resistance to microbial attack. Biodegradation of HPCF (carbon) began at the point of random orientation of graphite structure on the surface layer of the fiber, proceeding to the protuberance of a limited area in the layer and to the rupture of a limited area.