Structure and properties of iron containing glassy carbons

Glassy carbons containing iron were prepared from copolymers of furfuryl alcohol and ferrocene derivatives at heat-treatment temperatures from 500°C to 2500°C. The copolymerization produced a highly dispersed state of iron in carbonaceous matrices at least in the early stage of pyrolysis. Above 500°C, the homogeneously dispersed iron separated into irregularly spaced domains consisting of cementite, pure iron and iron compounds of unknown composition. Addition of iron resulted in a local graphitization of the glassy carbon at heat-treatment temperatures above 1000°C. At heat-treatment temperatures between 500°C and 800°C, electrical resistivities of the iron-doped carbons were much smaller than those of unmodified polyfurfuryl alcohol carbons but followed more or less the behavior of the latter for heat-treatment temperatures above 800°C.Measurements of mechanical properties indicated a remarkable increase in tensile strength of the low temperature carbons (500°C) with increasing iron content but the strength of the iron containing carbons decreased at higher carbonization temperatures.