To conduct research into the long-term preservation of fragile wool textile relics unearthed at archeological sites, it is essential to simulate the aging process and evaluate the factors affecting the degradation of wool fabrics. An accelerated aging method is therefore proposed to simulate the degradation process using either CaCl2 or NaCl in conjunction with hydrothermal treatment. The accelerated aging of wool fabrics was investigated by color measurement, scanning electron microscopy, cross-sectional observation, attenuated total reflection Fourier transform infrared spectroscopy, and amino acid analysis. Wool fabrics subjected to NaCl-hydrothermal or CaCl2-hydrothermal treatment exhibit an apparent yellowing with increasing treatment time. Fluctuations of cysteic acid and cystine dioxide content are shown to be the most prominent, and a distinct conversion of α-helices into β-sheets is observed with increasing treatment time. These results indicate that the effect of Ca2+ was greater than Na+ in promoting the degradation of disulfide groups in the hydrothermal degradation process.
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