Evaluation of the mechanical, thermal, and microstructural behaviour of gum Arabic reinforced polylactide (PLA) composite

Abstract

Polylactic acid (PLA) is highly regarded among polymeric materials due to its versatile properties, making it suitable for a variety of applications. This study aimed to functionalize pure PLA by blending it with gum Arabic (GA) through electrospinning, a technique recognized for producing nanofibrous materials with enhanced characteristics. The research further assessed the mechanical and microstructural properties of PLA/GA composites using a range of analytical methods, including tensile testing, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and X-ray diffraction (XRD). A thorough analysis of the results indicated that the electrospinning technique successfully produced bead-free nanofibers. The introduction of 5 wt% GA and higher concentrations resulted in a slight increase in the formation of sharp Bragg peaks while significantly reducing the XRD intensity of the PLA/GA composites by approximately 93%, reflecting an overall decrease in the crystallinity of the composite. This reduction notably affected the ultimate tensile strength (UTS), which dropped by around 49% below the 5 wt% GA addition, while ductility experienced an increase of about 78%. Moreover, the incorporation of GA transformed the smooth surface morphology of pure PLA into a rougher texture in the PLA/GA composite across all considered GA concentrations, further indicating a decrease in crystallinity and an increase in the amorphous character of the material.