Fourier-Transform Infrared Spectroscopy Analysis of the Changes in Chemical Composition of Wooden Components: Part II—The Ancient Building of Danxia Temple

Abstract

Abstract To investigate the decay extent of wooden components in the ancient buildings of Danxia Temple, the absorption peak intensities, changes in chemical components, and cellulose crystallinity of red oak (Quercus sp.), birch (Betula sp.), and maple (Pterocarya sp.) wooden components were determined and analyzed using Fourier-transform infrared spectroscopy. The results are as follows: (1) The absorption peak intensities representing cellulose and hemicellulose decreased or disappeared obviously in the decayed red oak wood (DROW); on the contrary, those representing lignin increased. The indexes of the content of cellulose, hemicellulose, and cellulose crystallinity also decreased; on the contrary, those of the content of lignin increased. Those results indicated that cellulose and hemicellulose in DROW were largely degraded by brown-rot fungi. (2) The absorption peak intensities representing cellulose and hemicellulose decreased both in the decayed birch wood (DBW) and the decayed maple wood (DMW), whereas those representing lignin increased. The indexes of the content of cellulose, hemicellulose, and cellulose crystallinity also decreased, whereas those of lignin increased. Those results showed that cellulose and hemicellulose in DBW and DMW were seriously harmed not only by insects but also by brown-rot fungi. By comparison, the extent of fungal damage was lower in DMW than in DBW.