Air-oxidation and anodization of pitch-based carbon fibers

Pitch-based high modulus carbon fibers were oxidized in air and characteriz ed using the coulostatic method in order to compare them with anodized fibe rs. The interfacial shear strength (IFSS) of these fibers to an epoxy resin was evaluated by a micro debonding test. The results showed a good correla tion between the differential double layer capacities, Cd, which were measu red by the coulostatic method, and the IFSS values for air-oxidized and ano dized fibers. In order to investigate the variation of the air-oxidation an d anodization in the tow, the coefficients of variation for the Cd and pola rization resistance (Rp) by the mono-filament coulostatic method were compa red. As a result, the variation of oxidation in the tow of air-oxidized fib er seemed to be slightly larger than that of anodized fiber. (C) 1999 Elsev ier Science Ltd. All rights reserved.