Towards biodegradable barrier packaging: production of films for single-use primary food liquid packaging

Abstract

This research aimed to obtain bio-degradable microfibrillated cellulose (MFC) films from a pine sawdust pulp for use as liquid containers. The films were combined with food-grade polyols (sorbitol, glycerol, and mannitol) to improve the hydrophobicity and provide barrier properties. Pine sawdust (a by-product of primary wood industrialization, highly available, and inexpensive) was treated with soda-ethanol and a 2-stage oxygen sequence. The resulting pulps were mechanically fibrillated to produce MFC with a disk refiner. The polyols were added to improve crosslinking and achieve a plasticizing effect. The films were dried at 25, 50, and 60 °C. The mechanical and barrier properties (tensile strength, elongation, vapor permeability, and water absorption), the crystallinity, and the transparency of the films were evaluated. Total migration tests were carried out to verify the compliance of the films with current regulations. Finally, the film’s biodegradation properties in soil under normal climatic conditions were evaluated.