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PDF :	19060265.pdf
title(En) :	Thermogravimetric Analysis of Woods
author(En) :	Yaomi Kumagai, Takeo Ohuchi, Masataka Ono
information :	Mokuzai Gakkaishi 19(6), 265-270 (1973)
assort :	Original Article
summary(En) :	Thermal degradations of 14 species of woods have been investigated using the technique of thermogravimetric analysis (TGA) between room temperature and 600°C.    TGA curves and differential thermogravimetric curves (DTG) were obtained at 10°C/min in flowing nitrogen and air atmospheres.    Initial significant weight loss began at 193-225°C in nitrogen and at 185-205°C in air.    DTG curves of wood of broad-leaved tree showed the tendency of constancy or decrease of the rate of weight loss in temperature range 283-300°C in air and 295-315°C in nitrogen, but these of wood of coniferous tree and red lauan showed no such phenomena.    The most active pyrolyses occurred at 350-370°C in nitrogen and at 320-330°C in air.    Assuming the first-order reaction for thermal degradation, the activation energies were calculated from the data obtained by dynamic TGA.    Thermal degradation took place by four reaction stages in temperature range 250-380°C in nitrogen and three reaction stages in 240-330°C in air except for some woods studied.    The activation energies were as follows: in nitrogen, 16-30kcal/mole at 250-285°C, 3-14 kcal/mole (wood of broad-leaved tree) and 16-30kcal/mole (wood of coniferous tree) at 285-320°C, 20-44 kcal/mole at 320-340°C, 42-89 kcal/mole at 340-370°C, in air, 22-38 kcal/mole at 240-270°C, 11-19 kcal/mole (wood of broad-leaved tree) and 22-30 kcal/mole (wood of coniferous tree) at 270-300°C, 54-82 kcal/mole at 300-330°C respectively.