Tunable biocomposite films fabricated using cellulose nanocrystals and additives for food packaging

Cong Chen; Wenjing Sun; Jinwu Wang; Douglas J Gardner

doi:10.1016/j.carbpol.2023.121315

Tunable biocomposite films fabricated using cellulose nanocrystals and additives for food packaging

Carbohydr Polym. 2023 Dec 1:321:121315. doi: 10.1016/j.carbpol.2023.121315. Epub 2023 Aug 19.

Authors

Cong Chen¹, Wenjing Sun², Jinwu Wang³, Douglas J Gardner¹

Affiliations

¹ School of Forest Resources, University of Maine, Orono, ME 04469, United States; Advanced Structures and Composites Center, University of Maine, Orono, ME 04469, United States.
² Institute of Materials (IMX), École Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland.
³ School of Forest Resources, University of Maine, Orono, ME 04469, United States; Advanced Structures and Composites Center, University of Maine, Orono, ME 04469, United States; Forest Products Laboratory, U.S. Forest Service, 1 Gifford Pinchot Drive, Madison, WI 53726, United States. Electronic address: jinwu.wang@usda.gov.

PMID: 37739509
DOI: 10.1016/j.carbpol.2023.121315

Abstract

Cellulose nanocrystals (CNCs) are considered a prospective packaging material to partially replace petroleum-based plastics attributed to their renewability, sustainability, biodegradability, and desirable attributes including transparency, oxygen, and oil barrier properties. However, neat CNC films are rigid and too brittle to handle or utilize for packaging applications. Hence different additives, including sorbitol, polyvinyl alcohol (PVA), chitin, and κ-carrageenan (CG) were selected to mix with CNCs for packaging film preparation. The influence of additive categories (plasticizer, nonionic polymer, weak cationic and anionic natural polysaccharide), and their concentrations on the performance of CNC suspensions as well as optical, barrier, mechanical, and thermal properties of CNC films were examined. The morphology and physical characterization including density, equilibrium moisture content, contact angle and water durability of the composite films were also determined. Sorbitol and PVA films had the best visible light transparency; mixing with chitin can effectively improve the water durability of CNC films, and CG changed the CNC film from hydrophilic to hydrophobic. Moreover, all CNC films exhibited sufficient oxygen barrier properties, high PVA content films attained the "very high" barrier grade. Thus, durable CNC films can be obtained by adding proper types and amounts of additives, which provides potential scenarios for practical application of CNC films in food packaging.

Keywords: Additives; Barrier properties; Cellulose nanocrystals; Films; Food packaging.