Leach and Mold Resistance of Essential Oil Metabolites

摘要

Purified primary metabolites from essential oils were previously shown to be bioactive inhibitors of mold fungi on unleached Southern pine sapwood, either alone or in synergy with a second metabolite. This study evaluated the leachability of these compounds in Southern pine that was either dip- or vacuum-treated. Following laboratory leach tests, specimens were evaluated for inhibition of mold growth for 12 weeks and analyzed quantitatively by GC-MS for residual metabolite(s). With the exception of geraniol, vacuum treating the specimens generally provided longer protection than dip-treating. Citronellol and carvone protected vacuum-treated specimens from mold growth for the 4-week duration of the ASTM D4445-10 test, but efficacy diminished after extending incubation beyond 4 weeks. Thymol completely inhibited mold growth for 12 weeks in both dip-treated and vacuum impregnated specimens even though GC-MS analysis showed that 49% thymol leached from the vacuum-treated specimens.