CELLULOSE CHAR STRUCTURE - A COMBINED ANALYTICAL PY-GC-MS, FTIR, AND NMR-STUDY

Bulk samples of microcrystalline cellulose were charred in an anaerobi c environment, at atmospheric pressure, and temperatures ranging from 190 to 390 degrees C. Curie-point pyrolysis-gas chromatography-mass sp ectrometry (Cu-Py-GC-MS) was used as an analytical tool for characteri zation of the resulting chars. Fourier-transform infrared (FTIR) spect roscopy and solid-state C-13 nuclear magnetic resonance (NMR) spectros copy were employed for verification of the results. The abundance of a romatic building blocks (furans, alkylbenzenes, and alkylnaphthalenes) in Cu-Py-GC chromatograms increases with the pretreatment temperature . FTIR and NMR show the breakdown of the pyranose polymer and gradual formation of a new intermediate polymer with an aromatic character whi ch disproportionates further and aromatizes at temperatures above 310 degrees C. A model for the formation of this intermediate polymer is p roposed. Cu-Py-GC-MS data are in agreement with the results of FTIR an d NMR.