Topochemical analyzes of furfuryl alcohol modified Radiata pine (Pinus radiata)

Furfurylation of wood is basically described as the polymerization of the organic monomer furfuryl alcohol (FA) in wooden tissue. Very little is known about the topochemistry of FA polymerization in the wood cell wall regarding the durability against biodegradation. Since brown rot degradation starts with a lignin modification the objective of the present work was to search for indications of potential bonds as a result of the FA modification. Furfurylated radiata pine (Pinus radiata) with three different weight percent gains was investigated by cellular UV microspectrophotometry (UMSP) to analyze chemical alterations of the individual cell wall layers. The topochemical studies were supplemented by light microscopy and scanning electron microscopy analyzes. The UV-absorbance values of the modified samples increased significantly compared to the untreated controls indicating a strong polymerization of the aromatic compounds. Highest UV-absorbance values were found in areas with the highest lignin concentration. The UV spectra of individual cell wall layers clearly indicated that condensation reactions took place which leads to the assumption that chemical bonds between FA and lignin were produced. More specific knowledge of the nature of these bonds will help to improve the biological resistance of furfurylated wood