Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE Flexible and biodegradable PLA/EVA films with enhanced ductility, barrier performance, and transparency were developed and theoretically validated, identifying an optimal composition (PE3) for next-generation sustainable packaging applications.

ABSTRACT
Polylactic acid (PLA) is a promising candidate among them for sustainable packaging applications. However, PLA's brittleness and limited barrier properties pose challenges in flexible packaging. To address these limitations, PLA has been modified with ethylene-vinyl acetate (EVA) to develop flexible, high-performance films suitable for sustainable packaging. EVA-embedded PLA systems with different compositions were prepared using a solution casting technique. The optimized film exhibited a maximum tensile strength of 70.99 MPa, a Young's modulus of 31 MPa, and an elongation at break of 25%. Interestingly, the addition of EVA has been found to significantly enhance the percentage elongation and ductility of PLA without compromising the other required features. Thermogravimetric analysis (TGA) revealed an enhanced thermal stability for the EVA-containing film, exhibiting the highest degradation onset temperature of approximately 450°C, while PLA alone recorded 360°C. Incorporation of EVA significantly reduced the water permeability by 70% and the solvent permeability by 19%–21% compared to neat PLA, while enhancing film transparency and biodegradability. The addition of EVA has been found to improve the transparency of PLA films by 7%. A comparison of the results with the theoretical models is also presented. A specific composition (PE3) was proposed for developing biodegradable packaging materials.