Preparation and physical properties of konjac glucomannan-polyacrylamide blend films

The blend films of konjac glucomannan (KGM) and polyacrylamide (PAAm) were prepared by using the solvent-casting technique. Transparent blend films were obtained in all blending ratios. The physical properties of the films were investigated by Fourier transform infrared spectroscopy, wide-angle X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, and by measurement of mechanical properties. The results indicated the occurrence of intra- and intermolecular interactions of the pure components, as well as the intermolecular interactions between KGM and PAAm through hydrogen bond formation. The thermal stability and mechanical properties of both tensile strength and elongation at break of the films were improved by blending KGM with PAAm. It was worth noting that the blend film had the greatest tensile strength when the KGM content in the blend films was around 30 wt%. Surface morphology of the films observed by SEM was consistent with the above-noted results. Furthermore, the water absorbability of the blend films was also investigated.