Cellulose nanocrystals reinforced κ-carrageenan based UV resistant transparent bionanocomposite films for sustainable packaging applications

In this work, kappa-carrageenan bionanocomposite films were prepared by solution casting of a mixture of kappa-carrageenan, glycerol, and various amounts of cellulose nanocrystals (CNCs, 0-9 wt.%). The structure and morphology of the bionanocomposite films were characterized by Fourier-transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, and scanning electron microscopy. Compared with kappa-carrageenan films, the kappa-carrageenan bionanocomposite films showed better mechanical and barrier properties (water and UV) and thermal stability. The water contact angle increased from 23.30 degrees to 71.80 degrees and the water vapor permeation decreased from 8.93 gm(-1) s(-1) Pa-1 to 4.69 x 10(-11) gm(-1) s(-1) Pa-1 in the kappa-carrageenan films loaded with 9-7 wt.% CNCs, respectively. The tensile strength and elongation at break of the films increased from 38.33 +/- 3.79 MPa to 52.73 +/- 0.70 MPa and from 21.50 +/- 3.72% to 28.27 +/- 2.39%, respectively, after CNC loading increased from 0 wt.% to 7.0 wt.%. These results indicated that the kappa-carrageenan nanocomposite films have potential applications in food packaging.