Efficient fabrication of biodegradable polylactic acid/poly (butylene adipate-co-terephthalate)/titanium dioxide films integrating ethylene catalysis and antibacterial activity for fruits and vegetables preservation

Abstract

Plastic packaging films have emerged as a rapidly advancing technology in the preservation of fruits and vegetables. To address environmental concerns and fruit deterioration from conventional plastics, a scalable method combining melt blending with flow casting to fabricate degradable packaging films integrating ethylene catalytic activity and antimicrobial functionality was developed. The nano titanium dioxide (TiO₂) particles were uniformly incorporated into the matrix formed by polylactic acid (PLA) and poly (butylene adipate-co-terephthalate) (PBAT) under the action of the melt blending flow field, and the PLA/PBAT/TiO₂ composite (PPTC) films with a thickness of 100 μm were cast successively. The PPTC films incorporating 20 wt% PBAT exhibited a 27.4 % increase in elongation at break compared with PLA films (5.4 %), demonstrating exceptional mechanical strength that consequently provided robust protective performance. The films significantly delayed kiwifruit maturation by maintaining 70 % ethylene catalytic efficiency while exhibiting potent antimicrobial effects with 91.5 % inhibition of E. coli and 99.8 % inhibition of S. aureus. This dual functionality preserved fruit hardness and enhanced overall postharvest quality. Critically, the films exhibited a mass loss of 39.49 wt% within 150 days during degradation experiments, demonstrating effective biodegradability. This approach provides a scalable solution for functionally engineered packaging films, simultaneously addressing fabrication efficiency and plastic pollution challenges.