Spectroscopic studies on the molecular interactions in chitin/poly (vinyl alcohol) blends

Abstract

The molecular interactions in chitin/poly (vinyl alcohol) (PVA) blends were investigated by FT-IR and high-resolution solid-state13C NMR techniques. With an increase in PVA content, the following spectral changes were observed: In a series of pure chitin/PVA blends, the intensity of the lower frequency portion of the IR amide I doublet decreased systematically, implying supression of the intramolecular hydrogen bondings of the amide C=O with O6H and/or N-H; concerning a blend system of water-soluble chitin (WSC, degree of deacetylation = 47%) with PVA, a significant shift was noted not only for the amide I band in the IR spectra but also for a CH peak of PVA in the13C CP/MAS spectra. These spectroscpic observations indicate that chitin and WSC are mixed with PVA at the molecular level in the respective blends.