CHEMICAL CHANGES DURING WOOD CUTTING
Scots pine (Pinus sylvestris) and poplar (Populus euramericana) species were chosen for the experiments.Sawdust was made by a circular saw with a rare tooth spacing for producing bigger particles beside the fine fractions. Particles were separated by a vibration separator with the sieve sizes 1 mm, 0.63mm, 0.315 mm, 0.1 mm and 0.063 mm. Infrared reflectance spectra of the particles were measured to determine the chemical changes generated by the cutting procedure.The experimental results showed that the grinding of wood resulted in bond rupture for all ether bond types appearing in the infrared spectrum. The number of conjugated and unconjugated carbonyl groups in the wood was significantly reduced during the cutting procedure. After bond breaks, oxidation and recombination processes occurred generating compounds similar to the aromatic structure of lignin, which were shown by increases in absorption at 1514, 1271 and 1231 cm-1