Thermal and heat-sealing properties of polyvinyl alcohol/cellulose nanocrystals-based nanocomposites for food packaging

Food packaging materials require advanced properties (UV barrier and antioxidant/antimicrobial) to extend the shelf-life of packaged products. Recently, we have developed biodegradable nanocomposites by incorporating cellulose nanocrystals (CNCs) and active agents (titanium dioxide nanoparticles and apple peel extract) into polyvinyl alcohol (PVA). These nanocomposites exhibited advanced properties and many demonstrable advantages in food packaging. Herein, the thermal stability, melting behaviors, and heat-sealing properties of these nanocomposites are investigated to demonstrate their potential production at the industrial level and practical use. The results showed that the PVA/CNC-based nanocomposites exhibited thermoplastic properties and had sufficient heat-sealability. The PVA/CNC-based nanocomposites presented lower melting temperatures (217.7–224 °C) than pure PVA (226 °C). Furthermore, their seal strengths (15.1–1238.1 N/m) are similar to those of petroleum-based food packaging polymers (polypropylene: 300–1100 N/m, low-density polyethylene: 677.7 N/m) and can be controlled by adjusting the sealing temperature, which is useful for various food packaging applications. © 2024 Elsevier Ltd