Abstract:

The ASE, crystallinity and characteristic of FTIR of super heat-treated Larix spp.( heat-treated temperature ranging from 180 to 240 ℃,heat-treated time was 4 h) were determined and characterized by the research. Results showed: the value of ASE increased along with the heat temperature increasing ranging from 180 to 220 ℃ and was beyond 60%, but when the heat-treated medium was nitrogen, the value of ASE was lower than that of air. The spectrum of FTIR demonstrated that the stretching vibration of —OH groups at 3 380 cm^-1 was diminished accompanying the enhancing heat temperature and obviously changed. The relative intensity of carbonyl group at 1 730 cm^-1 decreased with the increasing temperature. At the same treated situation, the hydroxide and carbonyl groups in the nitrogen were lower than those of oxygen. The tendency of crystallinity of super heat-treated Larix spp. was firstly increased, then decreased and finally increased. The value of crystallinity in the nitrogen was higher than that of air and over 65% under identical circumstances.

Key words: Larix spp., heat-treatment, dimensional stability, crystallinity, FTIR