Structural changes in biodegraded lime wood

The changes in structure of lime wood (Tilia cordata Mill.) decayed by Trichoderma viride Pers. have been investigated by FT-IR and 2D IR correlation spectroscopy. Wood was exposed to fungi for different durations up to 84 days, with decay assessed through mass loss and FT-IR.A decrease of intensities bands assigned to different vibrations from cellulose and hemicelluloses, with increasing intensities of the bands assigned to CO vibrations due to formation of oxidized structures was observed; and examined in details using 2D-correlation spectroscopy and the second derivative analysis in the exposure time range of 0–35 days. The formation of reactive species due to oxidation reactions induced by enzymes was evidenced. It has been also established that after longer degradation period oligomers and oxidized structures result, and finally small fragments containing carboxyl or carbonyl groups are formed, which lead to loss of structural integrity of the lime wood.