Characterization of hydroxyl groups of highly crystalline β-chitin under static tension detected by FT-IR

► Two OHs of β-chitin were identified by FTIR with tensioning in chain direction. ► Both peaks shifted to higher wavenumbers by tension, but the shift amount differed. ► O3H is located in chain's backbone, and O6H is located in a side-branch of the chain. ► Both are hydrogen bonded, but that of O3H would be more affected by tension applied. ► Thus the peak that shifted more severely under tension could be assigned to O3H.