Infrared spectroscopy on thermal behavior of cellulose - II. Analysis in situ between 25 and 450 degrees C

The part I of this work discusses the potentialities and limits of the in s itu spectroscopic analysis of cellulose by Diffuse Reflectance Infrared Fou rier Transform in an environment device. In this paper, we describe: the in situ evolutions of cellulose from 25 to 270 degrees C under N-2 or air; th e evolution of a partially thermolyzed cellulose residue during thermal tre atment from 25 to 450 degrees C and finally the oxidation in air of a cellu lose char at 300 degrees C. We observe a limited evolution of the cellulose below 270 degrees C. Only some carbonyle groups issued from rearrangement of cellulose chains are formed. The thermal treatment of the thermolyzed re sidue leads to a progressive aromatization of the solid between 270 and 450 degrees C. The oxidation in air induces the formation of oxygenated groups (carbonyles, carboxylic acids, lactones) and proceeds by reaction on both aliphatic and aromatic sites. Some dehydration of carboxylic groups to anhy drides are observed.