R. Menendez et al., INFLUENCE OF PITCH AIR-BLOWING AND THERMAL-TREATMENT ON THE MICROSTRUCTURE AND MECHANICAL-PROPERTIES OF CARBON CARBON COMPOSITES/, Journal of Microscopy, 185, 1997, pp. 146-156
This paper discusses the optimization of pitch properties as a matrix
precursor of C/C composites by subjecting the pitches to different pre
treatments to promote polymerization of the molecular components of pi
tch, which could improve carbon yield and density of the resultant car
bon materials, Two series of pitches were prepared by air-blowing of i
mpregnating coal-tar pitches at temperatures between 523 and 573 K, an
d thermal treatment at temperatures between 673 and 703 K, in an inert
atmosphere. Effects of pitch treatments on resultant coke texture and
porosity were monitored by polarized light microscopy. Unidirectional
laminar composites were prepared using the original and treated pitch
es and commercial PAN-based carbon fibres. Effects of pitch treatments
on the main microstructural features of composites are determined by
scanning electron microscopy and polarized light microscopy, and relat
ed to the mechanical properties of composites, Results show an improve
ment of the mechanical properties of composites in both series, partic
ularly for pitch treatments at 523 K/air in the air-blown series, and
at 698 K-5 h in the thermally treated one.