Wood cellulose films regenerated from NaOH/urea aqueous solution and treated by hot pressing for food packaging application

Abstract

Cellulose films made from ‘green’ solvent provide the possibility to mitigate environmental pollution caused by non-degradable plastic packaging. Herein, regenerated cellulose films were prepared from five wood pulps in NaOH/urea aqueous solution, dried either at ambient conditions or by hot pressing, and tested as biodegradable packaging materials. The results revealed that different wood origins did not cause much difference in the structure of cellulose films. However, hot-pressing could not only efficiently remove water from wet films, but also significantly improve the tensile strength and water vapor barrier property of regenerated films. The RC-P-HP film had the tensile strength of 85.00 ± 3.26 MPa, Young's modulus of 6.45 ± 0.36 GPa, and water vapor permeability of 3.59 ± 0.14 × 10−7 gm−1h−1Pa−1, and exhibited the similar capacity as the commercial plastic wrap during the preservation of cherry tomatoes for up to 16 days. Therefore, this study demonstrates a feasible strategy to fabricate wood cellulose films for biodegradable food packaging.