Sustainable bio-based film based on chitosan resin crosslinking with tannin, phytic acid and octadecylamine for food packaging application.

Chitosan and tannin are both promising renewable materials for food packaging; however, their effectiveness is limited by incomplete interactions between them. Therefore, phytic acid and octadecylamine were employed to create chitosan-tannin-phytic acid-octadecylamine (CTPO) films that are flame-retardant, UV-resistant, antibacterial and hydrophobic for food packaging applications. The findings indicate that the CTPO film exhibited excellent hydrophobicity and mechanical properties, with a water contact angle of 133.4°, a tensile strength of 19.19 MPa, and an elongation at break of 171.13 %. Furthermore, its LOI value reaches 35 vol%, while the peak heat release rate (pHRR) and total heat release (THR) of the CTPO film are recorded at 128.28 kW/m and 33.46 MJ/m, respectively. The peak smoke production rate (pSPR) and total smoke release (TSP) are 0.0046 m/s and 0.41 m, respectively. Moreover, bananas encased in CTPO film maintain significant freshness after 7 days with negligible weight loss. Following a 30-day burial in soil, the CTPO film exhibited a weight reduction of 10.8 %. Overall, the CTPO film developed in this study demonstrated significant potential for use in packaging film applications.