Scaled-up production of gelatin-cellulose nanocrystal bionanocomposite films by continuous casting

Abstract

In this study, continuous casting is proposed as a suitable approach to scale up the production of gelatin-cellulose nanocrystals (CNCs) bionanocomposites. The processing conditions and bionanocomposite properties were established based on the ζ-potential and gelatin content, and CNCs concentration, respectively. Gelatin film-forming solution at 20 wt% was required for proper continuous casting processing, leading to a productivity of 0.20 m² film/min, which was at least 1000-fold higher than that of the classical bench casting. The gelatin-CNCs bionanocomposites displayed transparency, flexibility, and improved UV-barrier and thermal properties. Adding only 0.5 wt% of CNCs resulted in an increase of 77 % and 48 % in the tensile strength and Young's modulus of gelatin, respectively. Comparison with previous nanocellulose-based nanocomposites pointed out the relatively superior performance of the gelatin-CNCs bionanocomposites obtained by continuous casting for various applications, including flexible food packaging.

Keywords: Bionanocomposite films; Cellulose nanocrystals; Continuous casting; Gelatin; Physical properties; Scale-up.