Abstract: High purity pine cellulose was extracted from pine sawdust by alkalization twice and acidification. The factors affecting purity of pine cellulose in the processes of alkalization and acidification were studied. the content of α-cellulose and nitric acid-ethanol cellulose in high purity pine cellulose was determined. The extraction process of cellulose was analyzed by IR and XRD. The results indicated that the optimal extraction conditions were as follows: the quality fraction of NaOH in first alkalization at 100℃ for 2h was 6%; the quality fraction of NaOH in second alkalization at 100℃ for 3h was 12%; the ratios of HNO3 and CH3COOH (V:V) in acidification at 100℃ for 30min was 1:3. The content of nitric acid-ethanol cellulose and α-cellulose in pine cellulose was 95% and 87% respectively. The recycle and environmental pollution of pine sawdust was solved to some extent and a new extractive method was got for cellulose.

Key words: pine sawdust, cellulose, extraction, aldalization