The role of extractives on the fire performance of Tectona grandis L.f. (teak) wood

Wood from teak (Tectona grandis L.f.) is a commercially prized material due to its strength, color, and natural resistance to decay and insects. Some of these properties are attributed in part to its high extractive content. The subject of this study was to investigate the influence of extractives on the fire performance of teak wood. Two sets of dimensionally identical (100 mm × 12.5 mm × 12.5 mm) samples were prepared. One set of samples was extracted using soxhlet extraction equipment in three steps: first, for 24 hours, using a mixture of acetone, ethanol, and toluene (1:1:4); next, for 8 hours, using ethanol; and last, with distilled water to remove water-soluble extractives. The fire performance of both sets was evaluated using a rate of burning test according to BIS IS: 1734 (Part 3)—1983. Extracted wood samples exhibited a significant change in weight and surface color compared to their non-extracted counterparts. The surface color tended to become lighter and weight reduced significantly for extracted wood samples. Importantly, the extracted samples displayed a significantly slower burning rate than the non-extracted ones. These findings of the present study highlight the role of extractives in determining the fire performance of teak wood and demonstrate that the presence of wood extractives negatively influences the fire performance of teak wood.