Pengaruh Karakteristik Kimia terhadap Sifat Mekanis dan Keawetan Alami Tiga Jenis Kayu Kurang Digunakan (Effect of Chemical Characteristics on Mechanical and Natural Durability Properties of Three Lesser-Used Wood Species)

C hemical, mechanical, and natural durability properties of three lesser-used wood species from North Kalimantan, namely nyatoh ( Palaquium lanceolatum ), pisang putih ( Mezze t tia leptopoda ), and sepetir ( Sindora wa l lichii ) woods , were analyzed to seek the interrelationships among them and give an overview related to their utilization . T he results showed that pH values of three wood species were categorized into moderate to weak acid levels . The extractive content s in hot and cold water a s well as in NaOH 1% of s epetir wood were higher than those of nyatoh and pisang putih woods. In contrast, the solubility in ethanol-benzene of nyatoh wood was the highe st . The a sh content in the three wood species were categorized into medium level . L ignin contents in sepetir and nyatoh wood s were classified as moderate, while lignin content in pisang putih wood was high. Holocellulose and hemicellulose contents in sepetir wood were higher than those in nyatoh and pisang putih woods, whereas alpha cellulose in sepetir wood was the lowe st . MOE values of the three wood species were classified as strength class of IV ‒ V, while MOR and compression parallel to the grain were classified as strength class of IV. The hardness value of nyatoh wood was higher than that of other woods. The durability of the three wood species was classified into poor (low durable). The relationship between chemical characteristics and mechanical properties of wood was primarily influenced by its major components (cellulose, hemicellulose, and lignin) , whereas natural durability was influenced by its minor components (extractives and inorganic materials) . Keywords:  lesser-used wood species, mechanical properties, natural durability, parameters interrelationship , wood chemical characteristics