Abstract: Caustic soda solution was utilized to treat and purify crude bamboo fibers. The effects of caustic soda concentration and temperature on the removal of impurities and the micro-structure properties of extracted bamboo fibers were investigated by the determination of weight loss and the analysis of SEM, FT-IR, UV-Vis and WAXD. Bamboo cellulosic fibers were not well separated due to the insufficient removal of impurities at 30℃ and 90℃. However, when crude bamboo fibers were treated at 100℃, 110℃ and 120℃ (esp. 110℃ and 120℃), the weight loss was high, the impurities could be adequately removed, so bamboo cellulosic fibers were easily separated out. High temperature and high caustic soda concentration promoted the dissolve of hemi-cellulose and lignin, but cellulose was easily degraded when caustic soda concentration was over 45 g/L at 110℃ and 120℃. In the present condition, extracted bamboo fibers belonged to celluloseⅠ. It was concluded that the extraction of bamboo cellulosic fibers should be appropriately performed at the conditions of high temperature, high pressure and low caustic soda concentration, which yielded about 81.8% bamboo fibers.

Key words: natural bamboo fiber, extraction, degumming, structure