Caffeine Interactions with Wood Polymers

Caffeine is a verified bioactive substance suitable for wood protection against pests. Unlike studies of the biocidal effects of caffeine, caffeine-wood bonds and interactions with wood polymer structures have not been studied whatsoever thus far. For this reason, caffeine (1 g/L) interactions with the main wood components (cellulose; hemicellulose; lignin and its precursors conipheryl alcohol, sinapyl alcohol, coumaryl alcohol) were analyzed in the present study. Caffeine concentrations were analyzed using UV-VIS spectrometry at wavelength 287 nm. The results confirmed caffeine variable binding with wood components in comparison to controls (pure caffeine). Cellulose and sinapyl alcohol did not interact with caffeine. Caffeine was bonded with the rest of the wood components in an increasing rank: conipheryl alcohol = lignin < hemicellulose < coumaryl alcohol. These results have a significant role in the protection of wood depending on its chemical composition and the wood species.