Functionalized Nanocrystalline Cellulose Reinforced PLA / PHBH Blend Films: Assessment of Mechanical, Thermal and Barrier Properties for Sustainable Packaging Applications

ABSTRACT In the current study, biodegradable polyester blend film of polylactic acid (PLA) and poly (3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate) (PHBH) have been prepared with a broad range of compositions employing reactive melt extrusion technique. Glycidyl methacrylate (GMA) functionalized nanocrystalline cellulose (CNC‐g‐GMA) was used as a reinforcing agent to improve the functional properties in the blend film. Mechanical findings revealed that PLA/PHBH film at 75:25 wt% exhibited improved synergism with 1 wt% CNC‐g‐GMA resulting an optimum increase in tensile strength (TS) to 52.25 MPa representing 39% improvement compared with neat PLA. Similarly, optimum tensile modulus (TM) of 3308.25 MPa was observed in the blend film with a consistent increase in elongation at break (EB) throughout the compositions. Heat sealing strength revealing nearly 7.98% improvement over neat PLA. Water and oxygen barrier analysis demonstrated 47.20% and 32.64% reduction indicating superior barrier resistance in presence of CNC‐g‐GMA creating a tortuous path. Interaction of CNC‐g‐GMA within the polymer matrix resulted improved thermal stability from 388.98°C to 410.98°C. The light scattering and the transparency in the film also improved thus making them suitable for packaging applications with superior strength and barrier resistance.