Abstract
Decomposition of cellulose crystallites in wood during pyrolysis was studied by X-ray diffraction using a tension wood of Populus maximowiczii (cottonwood), which contains highly crystalline cellulose. X-ray diffraction profiles were recorded at varied temperature up to 360°C. By one-hour isothermal treatments, the cellulose crystallites did not decompose at 300°C, but completely decomposed at 340°C. The change in equatorial diffraction profile was studied by temperature scan up to 360°C and by isothermal treatment at the critical temperature of 320°C. Along with the changes by thermal expansion, the changes in diffraction diagram revealed a characteristic discrepancy between the diminishment of crystalline order and the reduction in crystallite size; i.e., the intensity of crystalline reflections diminished steadily while the crystallite size decreased much more slowly. A model of highly heterogeneous decomposition is proposed to explain this behavior.
Original language | English |
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Pages | 521-524 |
Number of pages | 4 |
Volume | 55 |
No | 5 |
Specialist publication | Holzforschung |
DOIs | |
State | Published - 2001 |
Keywords
- Cellulose crystallites
- Populus maximowiczii
- Tension wood
- Thermal decomposition
- X-ray diffraction