Characterization of Guayule Resin as a Natural Wood Preservative: Carrier System and Leaching Rate Analysis

Abstract

The environmental and health concerns of traditional preservatives have led to investigations into an effective solution for protecting wood products with preservatives from natural sources. Guayule resin, derived from the Parthenium argentatum plant, has been reported to be effective as a wood preservative due to its bioactive properties. However, its high viscosity, limited penetration, and unknown leaching behavior may affect its durability and efficiency. This study investigated guayule resin concentration and solvent carrier efficacy. Yellow poplar and southern pine specimens were treated with guayule resin at four concentrations in three different solvents including acetone, ethyl acetate, and toluene. The leaching test was performed according to the AWPA E11-16 standard. Significant interaction between solvent type and concentrations of guayule resin were found in both species in which a lower mass loss was observed when 5% concentration of guayule combined with toluene as compared to any other guayule concentrations in southern pine. On yellow poplar specimens, 0.5% concentration of guayule in combination with toluene exhibited lower mass loss as compared to any other guayule concentration. In conclusion, toluene was found to be the best performing polar carrier system for guayule resin, considering its functionality and dose-dependence in both species.