High‐Barrier, Biodegradable Food Packaging

Biodegradable, high‐barrier, flexible and transparent food packaging are required to replace current multilayered, metal‐ or halogen‐containing packaging that is nonrecyclable and nondegradable. An “all‐green” solution for food packaging made of a polylactic acid (PLA) foil (25 µm) furnished with a glycol chitosan‐clay nanocomposite coating (1.4 µm) is presented here that surpasses state‐of‐the‐art high‐performance materials like metallized poly(ethylene terephthalate) or poly(vinylidene chloride) even at harsh conditions (OTR = 0.17 cm 3 m −2 day −1 bar −1 at 75% relative humidity). While the barrier side of the foil inhibits bacterial colonization, the uncoated PLA side assures biodegradability. Such a Janus feature in combination with the superb barrier performance renders this waterborne bio‐nanocomposite coating a valuable alternative to conventional less eco‐friendly food packaging materials.