Evaluation of the physicochemical and antimicrobial properties of the polyvinyl alcohol-mulberry leaf extract blend film

Abstract

In this study, mulberry (Morus nigra sp.) leaves extract (MN) was used as a structure modifier and antimicrobial agent in poly(vinyl alcohol) (PVA) blend films. We prepared PVA/MN blend films by solution casting at various concentrations. The SEM micrographs showed that PVA_MN75 has a smooth and continuous cross-sectional morphology with better compatibility. Fourier-transform infrared spectroscopy results suggest that a specific concentration of MN in PVA films facilitates a physical interaction that improves mechanical and thermal properties. The tensile strength of the films increased from 1.886 MPa to 2.907 MPa after adding mulberry leaf extract. Furthermore, the films were assessed for their solubility in water (12.116-15.833 %), absorption (9.800-21.610 %), and moisture content (6.530-14.257), which further demonstrates that blend films exhibit lower water solubility. Moreover, the soil burial biodegradation test indicates that PVA/MN film biodegradability is strongly affected by its MN concentration. Upon soil burial, all films showed an increase in biodegradability of 29% as burial time has prolonged in both soil and compost for thirty seven (37) days. Enhanced antibacterial activity has been observed in the PVA/MN film-forming solution and can be considered a promising substitute for polluting plastic packaging.