Chemical compositions, infrared spectroscopy, and X-ray diffractometry study on brown-rotted woods

The effect of brown-rot decay on the chemical composition and crystallinity of Masson pine was studied by exposing it to Wolfiporia cocos (Schwein.) Ryvarden and Gilbn. for durations of up to 15 weeks in the field. The holocellulose content, α-cellulose content, and wood crystallinity decreased slowly in the initial stage, followed by a significant reduction during the late stage. Pentosans did not have a significant reduction until 15-week decay, indicating that pentosans were degraded much more slowly than the cellulose. Strong correlations between the holocellulose and lignin content and alkali solubility, wood crystallinity, and IR band height ratio indicated that different wood properties affected each other during the degradation process. The results indicated that the slight degradation of amorphous cellulose and hemicellulose formed the entrance points for W. cocos to attack crystalline cellulose, and led to the serious degradation of the cell wall.