Chitosan–caffeine formulation as an ecological preservative in wood protection

Abstract

Nowadays, taking into account environmental degradation, climate changes, as well as, environmentally friendly regulations and increasing ecological awareness of con sumers, methods of wood protection without negative impact on the environment are being intensively developed. In this study, a mixture of chitosan and cafeine was proposed as ecological wood preservative. The aim of the research was to eval uate the application of chitosan (medium and high molecular weight) as an agent limiting the leaching of cafeine from the structure of treated wood. The resistance of pine wood treated with chitosan–cafeine preparations and ingredients of these preparations (cafeine and chitosan) to brown rot fungus—Coniophora puteana was assessed. The degree of cafeine leaching from the treated wood was determined by chromatographic analysis (cafeine concentration) and elemental analysis (nitro gen concentration). The results showed that chitosan limited cafeine leaching from wood, which was confrmed by chromatographic analysis and changes in the wood structure observed in FTIR spectra. Moreover, wood treated with chitosan–cafeine preparations showed resistance against C. puteana (mass loss about 0.5%); however, antifungal activity was reduced when treated wood was subjected to leaching with water (mass loss about 10%). The obtained results suggest that the chitosan–cafeine preparations can be promising ecological preservatives for the wood treatment.