| Summary: In this study, the efficiency of vegetable oils polymerized by epoxidation on wood protection was investigated. For this purpose, unsaturated double bonds in linseed and soybean oil were reacted by epoxidation with hydrogen peroxide. Sapwood of Scots pine (Pinus sylvestris L.) was impregnated with epoxidized and unepoxidized vegetable oils by using two different retention ranges (Ret A, 80-140 kg/m3 and Ret B, 170-270 kg/m3). In order to gain the properties of fungicidal and insecticidal to oils, secondary impregnation with boric acid and oil-boric acid emulsions have been tried. The effect of polymerized oils was also investigated in order to prevent leaching of boric acid. The physical (water uptake, dimensional stability), mechanical (modulus of rupture, modulus of elasticity, compression strength parallel to grain), biological (Coniophora puteana, Trametes versicolor fungi and Hylotrupes bajulus insect) thermal (TGA and DSC), analytical (boron analysis, FTIR) and morphological (SEM and light microscope) properties of the impregnated and control samples were determined. The decrease in iodine numbers of oils after epoxidation and the FTIR measurements indicated that the epoxidation process was successful. Compared to the control samples, it was determined that water repellency was achieved by 65% and dimensional stability was increased by 70% in the epoxidized groups after two weeks. Boric acid additions to vegetable oils were found to be effective against fungi and insect attacts, while vegetable oils reduced boric acid leaching by 47% in some groups. Due to damaging the wood components, the acetic acid used in the polymerization of oils adversely affected the mechanical properties. It was determined by SEM analysis that the oils were mostly located in late wood tracheids. According to TGA analysis results, the addition of boric acid to oils increased the resistance of oils to fire.
Key Words: Epoxidation, Vegetable Oils, Biological Resistance, Wood Modification, Leaching of Boron |
