Abstract

This research aims at detecting the hydrophobicity change in Samama (Anthocephalus macrophyllus) wood surface after hydro-thermo-mechanical modification. The modification started by soaking the test piece until water-saturated, followed with pre-compression at 100 °C for an hour. The second stage was impregnation of citric acid 10% using autoclave at pressure 7.5 kg cm⁻² for 4 h. The other test piece was only impregnated using distilled water, without citric acid, with the same pressure within the same time. Further, the second compression was conducted on the test piece impregnated only with distilled water and citric acid. It was conducted at 180 °C for 10, 20, 30, 40, 50 and 60 min. The compaction target was 20%. After conditioning for 2 weeks at room temperature (25 °C) and RH 85%, the test piece was soaked in distilled water for 24 h for the spring back test. The surface roughness and surface free energy were tested after the spring back test. The test result shows that the tangential surface of Samama wood impregnated with citric acid and compressed for 50 min (type CA50) has the smoothest tangential surface. The type also has the lowest SFE value of 36.193 mJ m⁻². In addition, the dispersive component of densified Samama wood surface seems to increase and, on the contrary, its polar component is reduced. The wood radial surface impregnated with citric acid tends to be rougher with a higher total SFE value than that of the tangential surface.

摘要

本研究旨在检测水热机械改性后 Samama ( Anthocephalus macrophyllus ) 木材表面的疏水性变化。通过将测试件浸泡至水饱和开始改性，然后在 100°C 下预压缩 1 小时。^{第二阶段是使用高压釜在 7.5 kg cm -2}的压力下浸渍 10% 的柠檬酸4小时。另一试片仅使用蒸馏水浸渍，不使用柠檬酸，在相同的时间内以相同的压力浸渍。此外，对仅浸渍有蒸馏水和柠檬酸的试验片进行第二次压缩。它在 180 °C 下进行 10、20、30、40、50 和 60 分钟。压实目标是 20%。在室温（25°C）和 RH 85% 条件下调节 2 周后，将试件在蒸馏水中浸泡 24 小时进行回弹试验。在回弹试验后测试表面粗糙度和表面自由能。测试结果表明，浸渍柠檬酸并压缩 50 分钟的萨玛玛木材（CA50 型）的切向表面具有最光滑的切向表面。该类型还具有最低的 SFE 值，为 36.193 mJ m ^-2. 此外，致密的萨玛玛木材表面的分散成分似乎增加了，相反，它的极性成分减少了。用柠檬酸浸渍的木材径向表面往往比切向表面更粗糙，总 SFE 值更高。