Chemical modification of the hydroxyl groups of wood can improve the properties of wood by providing moisture and biological resistance, as well as dimensional stability. Southern pine solid wood was chemically modified to various weight percentage gains (WPG) with epoxybutene (EpB, 8%-38% WPG). After modification, specimens were extracted with a toluene: ethanol (2:1) solution for 2 hours or water leached for 2 weeks. The equilibrium moisture content (EMC) at 30%, 65% and 90% relative humidity (RH) and 27 C was determined on all specimens. Laboratory soil block decay evaluations against the brown-rot fungus Gloeophyllum trabeum was performed and weight loss calculated by mass loss. Biological efficacy was found, and the biological resistance correlated with the lowering of the equilibrium moisture content, suggesting that the mechanism of efficacy was due to moisture exclusion. To assist in understanding the mechanism of effectiveness, small angle x-ray scattering (SAXS) and wide-angle x-ray scattering (WAXS) were both performed. Preliminary WAXS results showed that the modification did not significantly change the cellulose crystalline lattice parameters. Preliminary SAXS results showed that epoxide addition led to an increased polydispersity in the microfibril alignment and broader microfibril angle distributions, thus, suggesting that modification may target regions outside the microfibrils. Further experimentation is underway to confirm these results.

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