Functional silicones used for wood protection: preliminary study
C Reynaud, F Marchal, F Pochon, M Kutnik
Due to worldwide regulation the wood preservation domain is constantly changing. Silicones are used for different industrial applications as hydrophobic agents. This property could enable to reduce water uptake of wood treated with these compounds. Treated wood could then be less prone to dimensional variation and fungal attack, those parameters being driven by variations in wood’s moisture content. In the present study, Scots pine specimens were treated with different silicone-based products, either separately or in combination. The aim of combining silicones was to create a hydrophobic network protecting the surface of wood from water ingress and fungal attack.
In addition to fungal resistance and dimensional stability, protection against wood boring insects is required for most applications. Nevertheless silicones used in this study did not demonstrate any ability to protect wood against insects. Consequently, permethrin at different concentrations was combined to the first silicone.
Water uptake, resistance against Reticulitermes termite, longhorn beetle Hylotrupes Bajulus and basidiomycete fungi were evaluated after treatment of Scots pine with the different formulations of silicones. Resistance against insects and fungal decay was successfully improved for Scots pine treated with different silicones and water uptake was decreased. In addition, silicones applied to wood demonstrated limited leachability over time, supporting possible use for outdoor applications. The tested silicone-based formulations, containing only an insecticide but protecting wood both against insects and fungi, could be regarded as a more environmentally friendly alternative to traditional wood preservatives, which contains both insecticides and fungicides.
Keywords: silicone, hydrophobation, protection against insects and fungi