Insights into the effect of carboxylated cellulose nanocrystals on mechanical and barrier properties of gelatin films for flexible packaging applications

Autor(es)

Leite, Liliane S. F. ; Le Gars, Manon ; Azeredo, Henriette M. C. ; Moreira, Francys K. V. ; Mattoso, Luiz H. C. ; Bras, Julien

• Tipo de documento: Artigo Científico
• Fonte: International Journal of Biological Macromolecules; v. 280, p. 10-pg., 2024-09-26.

Resumo

In this study, gelatin/carboxylated cellulose nanocrystal (cCNC) bionanocomposite films were developed as an eco-friendly alternative to non-biodegradable flexible plastic packaging. Cellulose nanocrystals were modified by 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-mediated oxidation (cCNC) to strategically interact with amino groups present in the gelatin macromolecular backbone. Gelatin/cCNC bionanocomposite films (0.5-6.0 wt% cCNC) obtained by solution casting were transparent to visible light while displayed high UV-blocking properties. The chemical compatibility between gelatin and cCNC was deepened by electrostatic COO-/NH3+ interactions, as detected by FTIR spectroscopy and morphologically indicated by scanning electron microscopy (SEM). Accordingly, Young's modulus and tensile strength of films were largely increased by 80 and 64 %, respectively, specifically near the cCNC percolation threshold (4 wt%), whereas the water vapor permeability (WVP) was reduced by 52 % at the optimum 6.0 wt% cCNC content in relation to the non-reinforced gelatin matrix (0.10 vs. 0.18 g H2O mm m- 2 h- 1 kPa- 1). The oxygen transmission rates (OTR) of the gelatin/cCNC bionanocomposites were < 0.01 cm3 m-2 day- 1, making them technically competitive to most promising biopolymers like polycaprolactone (PCL) and poly(lactic acid) (PLA). This study reveals how TEMPO-oxidized cellulose nanocrystals can broaden the performance of biodegradable gelatin films for use in packaging. The gelatin/cCNC bionanocomposites also represent an effective approach for designing newly sustainability-inspired flexible materials from the surface modification of nanocelluloses targeting specific interactions with protein structures. (AU)

• Processo FAPESP: 18/00278-2 - Funcionalização, caraterização e avaliação das propriedades de nanocristais de celulose e seus bionanocompósitos a base de proteínas
• Beneficiário: Liliane Samara Ferreira Leite
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado