The formation of glasslike carbon by pyrolysis of polyfurfuryl alcohol and phenolic resin

Abstract The formation of impermeable glasslike carbon by thermal decomposition of 3-dimensionally cross-linked polyfurfuryl alcohol, phenolic resin, and mixtures thereof was found to be independent of the chemical structure of these resins. In each temperature range, pyrolysis products were obtained in which no pores were detectable by light and electron microscopy. The thermal decomposition is an exothermic process. This thermal behavior corresponds to the formation of the pyrolysis gases. It is concluded that the gaseous by-products must be transported through a capillary system having pore diameters smaller than 30 A. The micropore volume of this system reaches a maximum at 700°C. Natural graphite as filler material has a catalyzing effect on the crystalline ordering of the glasslike disordered carbon.