Study on the Difference of Chemical Properties among Five Acacia Species Woods I.Study on the Difference of Chemical Composition
Abstract: The difference of chemical composition among five acacia species woods (Acacia auriculaeformis, A. crassicarpa, A. cincinnata, A. mangium and A.melanoxylon ) were compared. The ash, holocellulose, α-cellulose, 1%NaOH extractive, benzene-ethanol extractive, pentosan,lignin and relative crystallinity contents were investigated. By this study, the chemical composition variable disciplinarians among the five acacia species woods were found. The results showed that they had almost the same chemical properties for A. auriculaeformis, A. crassicarpa and Acacia mangium; the chemical composition of A. crassicarpa had significant differences with that of A. cincinnata and A. melanoxylon, while the chemical composition between Acacia magnium and A. cincinnata as well as between A. cincinnata and A. melanoxylon also had remarkable difference. The contents of holocellulose for the woods (Acacia auriculaeformis, A. crassicarpa, A. cincinnata, A. mangium and A.melanoxylon) were 71.25%, 70.84%, 75.47%, 72.38% and 71.77% respectively;the contents of α-cellulose:45.30%, 46.47%, (50.15%), 46.48% and 43.99%;the contents of lignin:22.83%, 24.12%, 18.54%, 21.98% and 20.77%; the contents of relative crystallinity:58.74%, 43.36%, 43.42%, 39.74% and 41.89%;the contents of 1%NaOH extractive:22.02%, (21.20%), 22.73%, 22.00% and 26.20%;the contents of pentosan:22.98%, (21.20%), 24.68%, 23.20% and 24.72%;the contents of benzene-ethanol extractive:5.78%, 5.38%, 6.13%, 6.20% and 6.25%。