Evaluating the Effect of Biodiesel on the Efficacy of the Wood Preservative Copper Naphthenate
The efficacy of biodiesel as a co-solvent for copper naphthenate wood preservative treating solutions was evaluated using two fungal decay methodologies (AWPA E10-09, British Standard Method EN113). Four fungal species (Gloeophyllum trabeum, Trametes versicolor, Poria xantha, Postia placenta) and three wood species (Douglas fir, Southern yellow pine, Western red cedar) with six replicates were utilized in both studies. Two levels of biodiesel: diesel (30:70 and 50:50) were compared to diesel-only solvent systems for copper naphthenate treating systems and treated to AWPA recommended retentions. No differences in decay efficacy between the biodiesel blends and diesel-only treatment in either the AWPA or the EN113 decay studies were detected for either standard method. Copper distribution was evaluated using SEM-EDX and no differences were noted with either solvent system. It was determined that the presence of biodiesel did not have a negative impact upon the efficacy of copper naphthenate as a wood preservative.