influence of artificial weathering on acetylated beech solid wood and particleboard by spectroscopy and electron microscopy

this research was conducted to investigate the effect of acetylation on weathering resistance of solid wood and particleboard produced from acetylated particles of fagus orientalis. after 12 hours soaking in acetic unhydride, in order to achieve three levels of weight gain, 5, 9 and 16%, acetylated particles of bech wood were heated in oven at 120oc for 30, 90 and 240 minutes, respectively. also, after 12 hours soaking iacetic unhydride and heating at 120 oc for 240 minutes, the weight gain of solid wood reached to 10%. the particles were glued with 12% melamine urea formaldehyde (solids on oven dry mass of particles) and then, pressed. results showed that resistance to weathering increased by acetylation. by increasing level of acetylation from zero to 16%, difference between weathered and unweathered acetylated particleboard samples became more invisible. after weathering for 300 hours, the radial surface sem of acetylated beech solid wood showed that, with increasing of acetylation level, depth of surface cracks decreased and bordered pits approximately did not change.