Rheogical behavior of coal-tar pitch modified with p-methyl benzaldehyde

The chemical structures and morphologies of the pitches, including parent coal-tar pitch and the modified pitch, were analyzed using Fourier transform infrared (FT-IR) and scanning electron microscopy (SEM), respectively. Moreover, the rheogical properties of the modified pitch were measured using rotating coaxial-cylinder viscometer. The experimental findings are as following: (1) There exist many micro-fibers with a uniform distribution in the modified pitch, which is due to the polymerization between coal-tar pitch and PMB. (2) The apparent viscosity of the modified pitch is 78-548 mPa · s over the temperature range of 150-210°C when the shear rate is 100 s^-1, indicating that the modified pitch has good rheogical properties. (3) The viscous activation energy (E) of the modified pitch becomes large with the decrease of toluene soluble (TS) content, and the apparent viscosity becomes small with the increase of shear rate.