Characteristics of Spent Coffee Grounds Holocellulose-PVA Composite Film

Abstract

This study was conducted to produce a composite film with delignified spent coffee grounds-holocellulose (SCG-H) and PVA at different ratios and analyze the physicochemical properties. The SEM results showed that the composite film surface became rough as the concentration of SCG-H increased. In the XRD analysis results, the crystal structure was changed by crosslinking in the composite film, and there was no difference in the XRD pattern according to the mixing ratio. In addition, as the amount of SCG-H increased, the crystallinity of the film decreased. The composite film did not undergo pyrolysis even at about 480℃ or higher, which was considered to be due to the increased thermal stability by crosslinking. In the result of FT-IR analysis of the composite film, a peak of the ester C=O group was observed at about 1,720 cm-1. This indicates that SCG-H and PVA were crosslinked by citric acid. Meanwhile, the tensile strength and elongation of the composite films tended to decrease as the SCG-H concentration increased. This result indicates that SCG-H affected the crystallinity reduction of the composite film. It is expected that the output of this study can be applied to various biodegradable material industries such as agricultural mulching film and food packaging materials.