Paper Title
Effects of Superheated Steam Treatment on Mechanical and Physiochemical Properties of Rubberwood and Its Resistance to Termites and Fungal Attacks

Abstract
This research was aimed to investigate mechanical properties, color and cell-wall components changes, and durability of pre-dried rubberwood (Hevea brasiliensis) after superheated steam (SS) treatment. Wood samples were treated at different SS temperatures (140 to 180C) for 1 to 3 h. The highest compression strength parallel-to-grain, hardness and impact strength were found for samples treated at 160C for 3 h (30.7% higher than untreated), at 150C for 1 h (26.6% higher than untreated) and at 150C for 2 h (52.6% higher than untreated), respectively. The surface color after treatment was deeper than that of untreated wood. The number of accessible hydroxyl groups decreased and the relative cellulose crystallinity increased with SS temperature. Also, SEM micrographs of wood surface showed consistent decrease in starch particles with treatment temperature. Both decay and termite resistances of treated rubberwood improved with treatment temperature and time. Keywords - Rubberwood, Superheated steam treatment, Mechanical properties, Cellulose crystallinity, Decay resistance. This research was aimed to investigate mechanical properties, color and cell-wall components changes, and durability of pre-dried rubberwood (Hevea brasiliensis) after superheated steam (SS) treatment. Wood samples were treated at different SS temperatures (140 to 180C) for 1 to 3 h. The highest compression strength parallel-to-grain, hardness and impact strength were found for samples treated at 160C for 3 h (30.7% higher than untreated), at 150C for 1 h (26.6% higher than untreated) and at 150C for 2 h (52.6% higher than untreated), respectively. The surface color after treatment was deeper than that of untreated wood. The number of accessible hydroxyl groups decreased and the relative cellulose crystallinity increased with SS temperature. Also, SEM micrographs of wood surface showed consistent decrease in starch particles with treatment temperature. Both decay and termite resistances of treated rubberwood improved with treatment temperature and time. Keywords - Rubberwood, Superheated steam treatment, Mechanical properties, Cellulose crystallinity, Decay resistance.