Extractive contents of the juvenile stemwood and bark of teak

Teak wood is used at the juvenile stage due to short-rotation, therefore, this study aims to describe the extractive content of stem, bark, branch, and twig parts of the wood as value-added chemicals from secondary metabolites. Moreover, the main stems comprise of sapwood, heartwood, and bark while the branch and twig are made of sapwood together with bark. In this study, the sample trees were 6 and 8 years old with three replications from clonal superior teak wood and were extracted using n-hexane, methanol, and hot water as the solvents. The average of n-hexane, methanol, hot water, and total extractives ranged from 0.49 to 2.77%, 2.27 to 17.76%, 0.65 to 7.47%, and 5.96 to 25.40%, respectively. Furthermore, the total phenolic content from soluble n-hexane and methanol extracts ranged from 162.16 to 295.24 mg GAE/g, while the total soluble polysaccharides ranged from 166.28 to 423.97 mg GluE/g. The results showed that the 8-year-samples had higher values in methanol extractive content (MEC) and lower in hot-water extractive content (HWEC) than the 6-year-old trees. In addition, the bark together with sapwood in branch and twig parts had higher concentrations of MEC and total extractive content (TEC) compared to the main stems. For radial direction, MEC, HWEC, and TEC levels were greater in bark than in other parts. The branch and twig parts also had higher phenolic concentrations compared to the main stem at the base part. Meanwhile, the sapwood at the branch and twig parts have higher total soluble polysaccharide concentration compared to the main stem.

Study on permeability of Cunninghamia Lanceolata based on steam treatment and freeze treatment

In order to improve the permeability of Cunninghamia lanceolata, the weight gain rate of C. lanceolata was taken as index. The effect of time, temperature and water content on the weight gain rate of impregnated wood was analyzed by frozen and steaming treatment. By comparing the weight gain rate under different modification methods, the optimal modification process was determined. The results indicate that the optimum parameters of C. lanceolata were saturated water content (-25°C and 8 h) at this time, the three-day gain rate of silica sol impregnated at normal temperature and pressure was 15.058%. After C. lanceolata is pre-treated by superheated steam, the weight gain rate of C. lanceolata, which in oven-dried specimen (120°C and 3 h) contents was the highest, at this time, the three-day gain rate of silica sol impregnated at normal temperature and pressure was 15.291%. By comparing the results of pre-freezing with the results of superheated steam treatment of C. lanceolata, the latter will increase the permeability of C. lanceolata better. Therefore superheated steam treatment should be chosen as an effective method for the pretreatment.