Characterization of poly(vinylpyrrolidone)–konjac glucomannan blend films

Abstract

Abstract Blend films of konjac glucomannan (KGM) and poly(vinylpyrrolidone) (PVP) were prepared by using a conventional solvent‐casting technique and dried at room temperature. The structure and physical properties were studied by infrared spectroscopy (IR), wide‐angle X‐ray diffraction (WAXD), thermogravimetric analysis (TGA), differential thermal analysis (DTA), scanning electron microscope (SEM), and by measurement of mechanical properties. The changes of carbonyl stretching bands of KGM and PVP and hydroxyl stretching region of KGM were detected by FTIR analysis. WAXD analysis revealed that the film KP‐2 got the lowest crystallinity of all the films. The tensile strength and breaking elongation of the blend films reaches the maximum value at 10 wt % PVP content. The DTA curves indicated the existence of interaction between two kinds of macromolecules. Higher thermal stability was attained by konjac glucomannan through blending with PVP. These improvements are attributable to the existence of a certain degree of interaction between KGM and PVP molecules resulted from intermolecular hydrogen bonds. Air surface morphology of the films observed by SEM was consistent with the results mentioned above. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1049–1055, 2001