Effectiveness of acetic, propionic and butyric anhydrides to protect rubberwood from decayed by white rot Trametes versicolor

Abstract

Fresh rubber tree was harvested, cut into sized (100 cm x 14 cm x 25 mm) (l x w x t) and kiln dried (10-12 %) MC. The specimen sized of 5 mm x 20 mm x 20 mm (l x w x t) were prepared, undergone soxhlet extraction with toluene/methanol/acetone (4:1:1 by volume) for 8 hours, followed by oven dried at 103 °C for 24 hours and cooled in silica gel. The specimens were vacuum impregnated and then reacted with anhydrides for times ranging from 0.25 to 24 hours at 120 °C. The weight percent gain (WPG) was calculated and the chemical bonding was analysed with FTIR. All the specimens were leached in dionised water according to EN 84 (1997) and exposed to white rot in incubation room set at 22 °C (16 weeks). The study was found that modification only managed to reduce the rate of decay; without totally protected the rubberwood. Modified rubberwood was still classified as durability class 1 when compared to scott pine and beech woods. The final MC had a positive correlation with the weight loss following decay. The SEM showed that the hyphae were penetrated in the cells in both rubberwood.