FT-IR STUDY OF ROCKROSE AND OF CHAR AND ACTIVATED CARBON

Fourier transform-infrared spectroscopy was used in the study of rockr ose (Cistus ladaniferus, L.) and of rockrose chars and activated carbo ns. Chars were prepared by heating the starting material between 200 a nd 1000 degrees C in nitrogen. Also, a sample was obtained at 600 degr ees C in the atmosphere of the products of the thermal decomposition o f rockrose. This charred product was used in the preparation of activa ted carbons. It was heated at 800 degrees C in air, CO2 or steam to 40 % burn-off. The presence of oxygen groups and of olefinic and aromatic structures was detected in rockrose. The heat treatment of rockrose i n the range 300-500 degrees C produced the most significant changes in the chemical structure of the material. Olefinic C=C bonds and ether structures increased first in the chars and then the aromatic structur e developed. Above 500 degrees C, the oxygen groups decreased with the temperature increase. The charring method of rockrose also influenced markedly the chemical structure of the chars. The use of a greater ma ss of sample slowed down the pyrolysis of rockrose. The activated carb ons possessed aromatic C=C bonds and oxygen groups.