Investigation on The Effect of heat treatment in rapeseed oil on decay resistance of Populus deltoides wood

In this study the decay resistance of Populus deltoides sapwood heat treated in air and rapeseed oil were investigated. For this purpose، the samples of Cottonwood with dimensions 19×19×19mm in according to ASTM D 1413 standard were prepared. Heat treatments were performed at 180، 200 and 220°C temperatures for 2 or 4 hours in air and rapeseed oil. Then samples volumes losses were measured. The experimental samples were exposed to brown rot fungus (Coniophora puteana) and white rot fungus (Trametes versicolor) for 12 weeks. Then weight loss and moisture content of the samples were measured. Results showed that heat treatment improved the decay resistance of cottonwood. With increasing treatment time and temperature، the decay resistance increased. So that heat treatment with rapeseed oil at the temperature of 220 degrees for 4 hours، improved the decay resistance against C. puteana and T. versicolor 91. 5 and 90. 6 percent، respectively. The results also showed that، heat treatment in rapeseed oil had a better effect in comparison to air heat treatment on the improvement of Cottonwood decay resistance.