THE INFLUENCE OF THE NATURE OF STABILIZER ON THE DEGRADATION OF COAL TAR PITCH

Abstract

We studied the influence of the stabilizers on thermo-oxidative degradation of the main component (coal tar pitch) of a new material, pitch-composite. Based on the data of gravimetric and FTIR spectral analyses, it was established that individual stabilizers (irganox, melamine, calcium stearate and zinc stearate) in the amount of 2% interact with coal tar pitch at 1500C in the presence of air. Melamine, calcium stearate and zinc stearate decelerate (in contrast to irganox) destructive processes in the pitch which is accompanied by the formation of low-molecular compounds. It was shown that irganox initiates the degradation reactions with the formation of volatile compounds when interacting with pitch. When interacting with pitch components, zinc stearate and calcium stearate were stated to reduce the condensation of the system forming methylene bridges between the aromatic rings. Due to the reduced condensation of the aromatic pitch systems, the formation of lowmolecular volatile compounds is inhibited and the weight loss diminishes in the presence of calcium and zinc stearates. The obtained results should be taken into account when developing a complex stabilizer for basic stabilization of the pitch-composite.