Improvement of Dimensional Stability of Tropical Light-Wood Ceiba pentandra (L) by Combined Alkali Treatment and Densification
Deded Sarip Nawawi, Andita MARIA, Rizal Danang FIRDAUS, Istie Rahayu, Adesna Fatrawana, Fadlan Pramatana, Pamona Silvia SINAGA, Widya Fatrıasarı
Abstract
Densification is an effective method for improving the physical and mechanical properties of low-density wood. However, the set-recovery of dimensions was found to be the problem of densified wood due to low fixation during the densification process. Alkali pretreatment before densification is thought to be a modification process to improve the dimensional stability of densified wood. In this research, the wood samples used were boiled in a 1.25 N sodium hydroxide (NaOH) solution at different times, followed by densification for 5 h at 100°C. The alkali pretreatment for 1, 3, and 5 h of boiling increased the dimensional stability of densified woods and anti-swelling efficiency values were 8.52%, 63.24%, and 48.94%, respectively. The boiling of wood in NaOH solution decreased the holocellulose content, as well as lignin to a lesser degree, and a lower crystallinity index was observed. The lower hydroxyl groups and a higher proportion of lignin in treated samples seem to have contributed to the high dimensional stability detected.