Development and characterization of PBS and PBAT blend based sustainable films for food packaging applications

Abstract

The increasing environmental concern associated with non-biodegradable plastics have sparked significant interest in biodegradable alternatives such as polylactic acid (PLA), polybutylene succinate (PBS) and polybutylene adipate terephthalate (PBAT) for food packaging applications. While these polymers show potential, their individual properties often fall short of packaging requirements. The present study showed the optimization of barrier and mechanical properties of PBS/PBAT blend. The PBS/PBAT blends exhibited composition-dependent physical interactions and partial miscibility without external compatibilizers. PBS-rich blends displayed improved mechanical strength, moisture barrier performance, and surface hydrophobicity, while increasing PBAT content influenced flexibility, UV-shielding capability, and light-transmission characteristics. The FTIR spectroscopy confirmed successful blending through shifts in characteristic absorption bands. Water contact angle analysis showed increased surface hydrophobicity with higher content of PBS. The Water Vapor Transmission Rate (WVTR) of PBAT decreased significantly with PBS incorporation, demonstrating improved barrier performance. The UV-Visible spectroscopic results revealed increased absorbance in the UV region upon blending with PBAT, indicating improved UV-blocking capacity of blends while maintaining visible transparency. Scanning Electron Microscopy (SEM) confirmed phase-separated morphology particularly in PBAT-rich blends. Overall, the results demonstrate that the composition of the PBS/PBAT blend can be tailored to control mechanical, barrier, and optical properties, suggesting potential applications in biodegradable packaging.