2010 Volume 59 Issue 6 Pages 513-520
Excavated natural fibers (silk, hemp and ramie) found at three tumuli (3C-6C A.D.) in Nara prefecture were investigated by using synchrotron radiation FT-IR microscopy at JASRI (SPring-8), beamline BL43IR. While three tumuli were kept in different long-term preservative environments, comparative studies on excavated fibers were performed for the identification of textile fibers, and for investigating the degraded state of respective fibers. Silk fibers are usually heavily degraded, and hence amide I and amide II peak patterns show different appearances compared with that of modern reference silk fibers. These phenomena are in accordance with the present author's analysis published separately. In short, the change in the spectral pattern is mainly due to transformation of the second structure components of the amide II peak during long-term preservation in various environments. Besides, the spectra pattern sometimes shows a small variation in the co-presence of metallic objects in tumulus. Plant fibers, such as hemp or ramie, are not severely degraded compared with silk fibers, and they usually show common spectra with plant fibers of a modern reference material. Since the plant fibers are in principle composed of cellulose molecules, exact identifications of materials are rather difficult by only the infrared spectrum. In summary, it was shown that excavated textile fibers sometimes show the small variation in the spectral pattern according to a difference in the preserved environment.
