INFLUENCE OF CHEMICAL TREATMENTS ON THE BEHAVIOR OF A BITUMINOUS COALIN THERMAL ANALYSES

The influence on its thermal behaviour of the structural modifications afforded to a bituminous coal by several chemical treatments (reducti on, alkylation, oxidation followed by butylation) was studied by therm ogravimetry (TGA) and oxidative pyrolysis (Ox-Py). The results were di scussed in relation to the structural information already obtained by infrared spectroscopy and with the rheological properties characterize d by thermomechanical analysis. These results pointed out that the cla ssical behaviour of the bituminous coal is highly modified after chemi cal treatments. For example, the weakening of the intermolecular inter actions, after alkylation, is evidenced by the increase of the weight losses between 180 and 800 degrees C (up to 90-95% after O-butylation) .