Development of Biodegradable Plastic Films for Food Packaging

As part of a collaboration with an industrial partner specializing in biodegradable plastics, researchers worked on the development of eco-friendly plastic films intended for food packaging. These films are made from blends of biodegradable polymers, containing at least 30% PLA (polylactic acid), a plant-based plastic.

The manufacturing process used for these films is called blown film extrusion, and the final products must meet strict requirements:

• High tear resistance (greater than 50 N/mm in the transverse direction),

• Compliance with food standards (food contact, migration, biodegradability of components).

🔬 Two approaches were tested to improve blend quality:

1. Reactive compatibilization
A chemical additive was introduced to enhance adhesion between the two plastics (PLA and PBAT). This led to better dispersion and increased film strength. One particular additive enabled very high tear resistance, thanks to specific PLA crystallization and homogeneous dispersion in the blend.

2. Non-reactive compatibilization
A triblock copolymer (PLA-PBAT-PLA) was synthesized in the laboratory to act as a "bridge" between the two plastics, without chemical reaction. This copolymer was added to the blend, significantly improving tear resistance, especially in the longitudinal direction.

Conclusion
Both approaches made it possible to produce biodegradable films that are stronger, more efficient, and compliant with food standards, paving the way for eco-friendly alternatives to conventional plastic bags used in food packaging.

Another collaboration with an industrial partner enabled the development of biodegradable food packaging resistant to creep at 100 °C, using the extrusion–calendering process combined with a post-treatment of the produced film.

Would you like more details on the compatibilization methods or the performance of the films obtained?

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