Thermal degradation behavior and kinetic analysis of spruce glucomannan and its methylated derivatives.
The thermal degradation behavior and kinetics of spruce glucomannan (SGM) and its methylated derivatives were investigated using thermogravimetric analysis to characterize its temperature-dependent changes for use in specific applications. The results were compared with those obtained for commercial konjac glucomannan (KGM). The SGM and the KGM exhibited two overlapping peaks from 200 to 375°C, which correspond to the intensive devolatilization of more than 59% of the total weight. Differences in the pyrolysis-product distributions and thermal stabilities appeared as a result of the different chemical compositions and molecular weights of the two GMs. The Friedman and Flynn-Wall-Ozawa isoconversional methods and the Coats-Redfern were adopted to determine the kinetic triplet of the intensive devolatilization region. Both GMs can be modeled using a complex mechanism that involves both a Dn-type and an Fn-type reaction. The comparative study of partially methylated GM indicated higher homogeneity and thermal resistance for the material with the higher degree of substitution.
Department of Fibre and Polymer Technology, Royal Institute of Technology-KTH, SE-100 44 Stockholm, Sweden.
Rosana
R
Moriana
Department of Fibre and Polymer Technology, Royal Institute of Technology-KTH, SE-100 44 Stockholm, Sweden.
Yujia
Y
Zhang
Department of Food Chemistry, Technische Universität Braunschweig, Schleinitzstraße 20, D-38106 Braunschweig, Germany.
Petra
P
Mischnick
Department of Fibre and Polymer Technology, Royal Institute of Technology-KTH, SE-100 44 Stockholm, Sweden; Wallenberg Wood Science Center, The Royal Institute of Technology and Chalmers University of Technology, SE-100 44 Stockholm, Sweden.
Jiebing
J
Li
Department of Fibre and Polymer Technology, Royal Institute of Technology-KTH, SE-100 44 Stockholm, Sweden. Electronic address: monicaek@kth.se.
Monica
M
Ek
D002400:Cathartics / Q000737:chemistry*; D006358:Hot Temperature; D007700:Kinetics; D008351:Mannans / Q000737:chemistry*; D008745:Methylation; D028222:Picea / Q000737:chemistry*; D013818:Thermogravimetry
D002400:Cathartics; D008351:Mannans; C022901:(1-6)-alpha-glucomannan
Kinetic triplet; Konjac glucomannan; Methylated glucomannan; Spruce glucomannan; Thermal degradation behavior; Thermogravimetry