Multi-layer oil-resistant food serving containers made using cellulose nanofiber coated wood flour composites

Abstract

Cost-effective, eco-friendly, and oil and grease-resistant food serving containers were made from wood flour with cellulose nanofibrils (CNF) or lignin-containing cellulose nanofibrils (LCNF) coating layers on the surface and in the bulk. The multi-layer wet-on-wet cellulose nanofiber composites were developed using a vacuum filtration process. All composites showed excellent oil/grease resistivity according to the "kit" test passing #12, the highest possible. The surface free energy and water contact angle showed that the composites with LCNF coating were more hydrophobic than the ones coated with CNF made from bleached pulp fiber. All composites had higher flexural and tensile properties compared with commercial food containers where the mechanical properties increased with increasing binder content and had acceptable thermal stability. Overall, the cellulose nanofiber composites possess excellent mechanical and barrier properties and can be considered as a wood-flour-based (pulp-free) and poly-fluoroalkyl substances (PFAs)-free alternative for oil-resistant commercial food serving containers.

Keywords: Cellulose nanomaterial; Oil and grease resistance; Poly-fluoroalkyl substance; Sustainable food container; Wood particle.