Change in Molecular Mass of Pitch on Thermodestructive Polycondensation of Heavy Pyrolysis Tar

摘要

By determining the molecular mass of pitch from heavy pirolysis tar, additional information may be obtained regarding the thermal polycondensation and quality of pitch. The weighted mean molecular mass of toluene-soluble components of the pirolysis pitch is determined by gel-permeation chromatography. The molecular mass of the components in specific petroleum-pitch fractions is studied as a function of the time and temperature employed in isothermal holding of the heavy pirolysis tar. The weighted mean molecular mass of toluene-soluble components depends on the heat treatment of the pirolysis tar and the softening temperature of the petroleum pitch.