Monitoring uptake and penetration of pesticides during impregnation of pine (Pinus sylvestris) and spruce (Picea abies) wood with bio-based microemulsion gel formulations
IRG/WP 20-30756
D Messaoudi, K Ruel, J-P Joseleau
Even in dry state wood is susceptible to biological degradation. Preservation against biological decay in exposed conditions is conventionally achieved by impregnating the wood with pesticides applied at professional and industrial levels. Impregnation of wood with preservatives is a complex process that involves wood macro- and microstructure, and the physical characteristics of woods. Here we focused on pine (Pinus sylvestris), an easily impregnable species, as opposed to spruce (Picea abies), a refractory species. In this work, the two species were impregnated with commercial bio-based emulsion formulations containing insecticide and fungicide agents. Penetration and uptake of the active agents were evaluated on laboratory specimens. The impact of different modes of application, dipping, surface spraying, and vacuum-impregnation, on the retention and distance of penetration of the active agents, cypermethrin, permethrin and propiconazole was assessed by gas liquid chromatography coupled to mass spectroscopy. Due to the suitable combinations of solvents and surfactants of our bio-based emulsions of low-toxicity and minimal environmental impact, rapid wood penetration enabled high retention yields. The difference of penetrability of pine versus spruce is discussed in relation to their anatomical characteristics, and their conducting cells network. The present data demonstrate the penetration and retention performances of these bio-based formulations.