Decay, insect, and termite resistance of wood modified with epoxidized vegetable oils

Abstract

Abstract Samples of Scots pine sapwood were treated with epoxidized linseed and soybean oils to improve decay, insect and termite resistance of wood. Non-epoxidized (raw) linseed and soybean oils were included as reference treatment in the study. In the epoxidation process, hydrogen peroxide was used to open double bounds, and acetic acid was added as a catalyst. Two retention levels, Ret A (80–140 kg m−3) and Ret B (170–270 kg m−3), two impregnation methods (full cell and empty cell) and emulsion technique were used. Samples treated with epoxidized oils had significantly lower mass losses than untreated samples while epoxidized oils showed higher mass losses than unepoxidized oils for Coniophora puteana and Trametes versicolor according to EN 113 for decay test. By adding boron, fungicidal properties were introduced to the treatment. All the vegetable oils showed 100% the mortality rate against larvae of Hylotrupes bajulus according to EN 47. Moreover, leached wood samples treated with oils also showed 100% larvae mortality. Additionally, termite testing based on EN 117 revealed 100% Reticulitermes lucifugus mortality for all leached oil treated samples.