Effects of glycerol as a plasticiser on mechanical and physical properties of chitosan-PVA-glycerol films

Abstract

Chitosan-PVA-based films have attracted attention for applications in biotechnical devices, packaging, and flexible electronics due to their biodegradability, mechanical strength, and tuneable physical properties. This study investigates the effect of glycerol as plasticizer on the mechanical and physical properties of Chitosan-PVA-Glycerol films. Glycerol content was varied from 3.0 mL to 1.0 mL, while PVA (1.25 g), chitosan (3% w/v), and processing parameters (temperature, stirring speed, mixing time) were kept constant. The films were characterized using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), tensile testing, and contact angle measurements. Increasing glycerol content enhanced film flexibility and elongation at break, but excessive glycerol reduced tensile strength and increased water absorption. Lower glycerol content resulted in higher rigidity, lower moisture uptake, and increased brittleness. Optimal properties were achieved at intermediate glycerol concentration, suggesting a balance between flexibility and mechanical integrity. These results aid the design of chitosan-PVA-glycerol films for diverse applications.