HIGH-TEMPERATURE PYROLYSIS OF NOVOLAC RESIN BIOMASS COMPOSITES

Composites of novolac resin (N.R.) and biomass derived from olive ston es(OL.B.), in various proportions, were cured with hexamethylenetetram ine (HTA) and pyrolyzed up to 900 degrees C. The pyrolysis mechanism w as monitored using TGA and gas chromatography. The pyrolysis regions, as well as important pyrolysis parameters of the materials used, were determined. Cured and pyrolyzed composites of N.R./OL.B. varied from 2 0/80 to 75/25, exhibiting at temperatures up to approx. 600 degrees C lower weight losses than expected by the rule of mixtures, owing to ad ditional cross linkages of lignin with HTA. This stabilization effect vanished during pyrolysis at higher temperatures because of the breaki ng of other chemical bonds, e.g. cross linkages. The release of CH, du ring the pyrolysis of OL.B. is derived from the lignin contained in OL .B. The other gases, CO, CO2 and H-2, could be formed from celluose, h emicellulose and lignin which are the main components of OL.B. The use of N.R. in the initial mixture with OL.B. reduces the weight losses d uring pyrolysis compared with OL.B. alone. A heating rate of 1O degree s C/min was necessary for the carbonization processes of OL.B. and its mixtures with N.R. in order to promote minimum weight loss of materia l and minimum pyrolysis time.