Carbon disc of high density and strength prepared from synthetic pitch-derived mesocarbon microbeads

Binderless carbon discs were prepared from mesocarbon microbeads (MCMB) der ived from the synthetic naphthalene pitch without and with carbon black. Th e carbonized discs were evaluated in terms of physical properties and textu res. Carbon black included in the stabilized MCMB was found to enhance sign ificantly the compressive strength of the disc by suppressing the formation and propagation of the fissures and voids in the disc. Strikingly high com pressive strength of 420 MPa, bulk density of 1.71 g/cm(3), and large volum etric shrinkage of 33% were successfully obtained by calcining the disc at 1300 degrees C, which were prepared from the stabilized MCMB with 3% BP2000 (Black Pearls 2000). The. disc of no stabilization without carbon black ex hibited a flow texture with large voids and deformed shape. Oxidative stabi lization at 300 degrees C for 1 h provided the fine mosaic texture in the d isk with the excellent shape stability and homogeneous shrinkage. The discs from MCMB with BP2000 and KB (Ketjen Black) stabilized at 270 degrees C fo r 1 h showed the intimate adhesion among MCMB particles with homogeneous te xture, no large fissure being found in the calcined disc, corresponding to their higher mechanical strength. No stabilization of MCMB with carbon blac k provided inferior strength and shape stability to that of stabilized MCMB with carbon black, but much superior to those of MCMB without carbon black regardless of the stabilization. (C) 1999 Elsevier Science Ltd. All rights reserved.