Affiliation: | a Pulp and Paper Research Center, University of Quebec in Trois-Rivieres, PO Box 500, Trois-Rivières, Quebec, Canada G9A 5H7 b Center for Research on Science and Engineering of Macromolecules, Wood Science, Faculty of Forestry, Laval University, Quebec, Canada G1K 7P4 |
Abstract: | The thermal degradation behavior of cellulose fibers and some fibrous cellulose esters with partial degree of substitution has been studied by thermogravimetry analysis (TG) and differential scanning calorimetry (DSC). Cellulose esters were prepared by heterogeneous esterification in Py/TsCl with unsaturated or saturated long chain organic acids [undecylenic (C11), undecanoic (C11), oleic (C18) and stearic (C18)]. The thermal degradation of cellulose fibers follows a one-step process. The thermal stability of cellulose esters is inferior to that of unmodified cellulose fibers and the thermograms show a two-step degradation process, probably controlled by crosslinking reactions, which occur during thermal decomposition. Exothermic peaks in the DSC thermograms are also an indication of such reactions. Kinetic parameters such as the activation energy E, order of decomposition n, and frequency factor Z were obtained following the Friedman method. The cellulose sample followed first order of decomposition, however for cellulose esters higher orders were observed. |