Effect of cashew shell biomass synthesized cardanol oil green compatibilizer on flexibility, barrier, thermal, and wettability of PLA/PBAT biocomposite films

The bio-based polymer blend of polylactic acid (PLA)-polybutylene adipate-co-terephthalate (PBAT) incorporated with cashew shell biomass synthesized cardanol oil (CARD) was prepared by solution casting method. The various formulations were prepared with PLA/PBAT(90/10) polymer blend containing 1%, 3%, and 5 wt.% of cardanol oil. All the prepared PLA/PBAT films were subjected to characterization techniques such as surface morphology, Fourier transform infrared spectroscopy, mechanical, thermal stability, X-ray diffraction, film color, opacity, wettability, and antimicrobial properties. The FTIR and XRD results confirmed the effective miscibility and molecular interactions of cardanol oil in PLA/PBAT blend. Further, the results of TGA analysis showed thermal stability improvement in PLA/PBAT bio-based film by the addition of cardanol oil. The homogeneous distribution of cardanol oil droplets on the PLA/PBAT blend was confirmed by observed SEM and TEM images. The mechanical result proved that the addition of 5 wt.% of cardanol oil into the PLA/PBAT blend increases the elongation at break. Moreover the bio-based PLA/PBAT film shows good barrier against water vapor and a poor barrier against oxygen permeability. The presence of cardanol oil in the PLA/PBAT matrix helps to enhance the optical and wettability properties of prepared bio-based film. Finally, it is proved from the investigational results that the PLA/PBAT/cardanol biodegradable films may be recommended to use in food packaging applications wherever high flexibility, water vapor barrier, thermal stability, antibacterial resistance, and less water absorption properties are required.