Triphenyl Acetic Glyceroate as a sustainable multifunctional additive for developing transparent, biodegradable, and flexible polylactide green alternative to polyethylene-based films for food packaging

Polylactide-based materials represent a promising bio-based alternative to traditional food packaging polymers. However, their widespread use is still limited due to significant drawbacks, such as brittleness, high gas permeability, and biodegradability only under specific conditions. This work introduces fully bio-based Triphenyl Acetic Glyceroate (TPAG), synthesized through a solvent-free and mild conditions valorization of glycerol and phenylacetic acid, as a polylactide (PLA) plasticizer and multiple property-enhancer for extending foodstuff shelf-life. After optimizing TPAG synthesis and confirming its structure through FT-IR and NMR, PLA-based films are prepared at different TPAG contents (0, 5, 10, and 20 phr). Detailed investigations of the films’ thermal, mechanical, optical, hydrodynamic, barrier, antioxidant, antibacterial, migration, and biodegradation characteristics are carried out. TPAG shows a significant plasticizing effect while maintaining high transparency and improving PLA's antioxidant, antibacterial and UV-blocking activities. Moreover, a notable lowering in oxygen and water vapor transmission rate is detected, revealing water vapor barrier properties closer to LDPE. Migration tests verify the material's compliance with European regulations up to 10 phr, and BOD assessments in seawater indicate improved biodegradability. Fresh food preservation is evaluated on pear slices, showing limited variation of color, acidity, antioxidant power, and weight loss comparable to LDPE-based commercial packaging.