# Tailoring PLA/Gelatin Film Properties for Food Packaging Using Deep Eutectic Solvents

## TL;DR

This study explores how adding gelatin and a deep eutectic solvent to PLA films can improve their properties for compostable food packaging.

## Contribution

The novel use of a deep eutectic solvent with gelatin to modify PLA properties for sustainable packaging is introduced.

## Key findings

- Direct incorporation of modified gelatin improves interfacial interactions and dispersion in PLA films.
- Deep eutectic solvent enhances processability and crystallinity while reducing thermal transition temperature.
- Hydrophilicity increases water vapor transmission and accelerates biodegradation of the films.

## Abstract

This work investigates the modification of poly(lactic acid) (PLA) film properties for food packaging applications through the incorporation of modified gelatin (Gel-mod) and a choline chloride/glycerol deep eutectic solvent (DES). PLA/Gel-mod/DES materials were melt-processed and evaluated with respect to structure, morphology, thermal and mechanical behavior, processability, wettability, barrier performance, and compostability. Two incorporation routes were investigated for adding Gel-mod into the PLA matrix: direct incorporation and masterbatch preparation. FTIR and SEM analyses confirmed improved interfacial interactions and more homogeneous dispersion when Gel-mod was directly incorporated, compared with the masterbatch route. DES acted as an effective plasticizer and nucleating agent, reducing Tg, increasing crystallinity, and enhancing processability while maintaining thermal stability. Mechanical properties decreased relative to neat PLA, primarily due to increased crystallinity and chain scission. PLA_4Gel-mod demonstrated a more balanced performance, with higher elongation at break and improved processability than the other formulations, likely due to its single processing cycle, which minimized PLA degradation. Increased hydrophilicity led to higher water vapor transmission rates, correlating with accelerated biodegradation. Overall, the synergistic incorporation of DES and gelatin provides a viable strategy to tailor PLA properties, enabling the development of compostable packaging films suitable for sustainable food contact applications.