CHARACTERIZATION OF PITCHES BY X-RAY-SCATTERING AND DIFFERENTIAL SCANNING CALORIMETRY

In this study X-ray investigations of distilled and partly pyrolysed p itches were performed at moderately small scattering angles. The avera ge molecular diameters, determined from the peak maxima at moderately small angles, increase with the temperature of heat treatment. In the case of pitch distillation, the increase of the molecular diameter cor relates with the increase of the glass transition temperature measured by differential scanning calorimetry (d.s.c.). It was found that both X-ray and d.s.c. methods are well adapted to check pitch transformati on during heat treatment.