Effects of the geometry of reinforcement on physical properties of sodium caseinate/TiO 2 nanocomposite films for applications in food packaging

NURYS TATIANA HOYOS MERLANO; LUCAS GUZ; VIRGINIA BORRONI; ROBERTO CANDAL; MARÍA LIDIA HERRERA

BIOPOLYMERS

JOHN WILEY & SONS INC

Lugar: New York; Año: 2023

0006-3525

Plastic materials for food packaging are being replaced by biodegradable films basedon biopolymers due to the adverse effects they have had on animal life and theenvironment. In this study, nanocomposite films containing 2.5 wt % sodium caseinateand 2 wt % glycerol were reinforced with 0.1 or 0.2 wt % nano TiO 2 prepared in twoforms: spheres (P25) and tubes. The effects of nanoreinforcement geometry onmechanical, tensile, barrier, thermogravimetric, and optical properties, and distributionof nanoparticles were described. The interactions among film components wereanalyzed by FTIR. Addition of nanotubes significantly increased E’ (341 wt %) and E’’(395 wt %) moduli, the Young modulus E (660 wt %), the residual mass at 500°C (38wt %), and color change (6.78) compared to control film. The compositional mappingstudies showed that P25 nanoparticles were homogeneously distributed between thesurfaces of the film while nanotubes were found on the bottom surface. The changes inposition of the FTIR spectra signals as compared to pure protein signals indicatedstrong matrix/reinforcement interactions. In addition, the changes in intensity in 1100,1033, and 1638 cm -1 FTIR signals suggested formation of a protein/Tween 20 ester.The geometry of reinforcement was highly relevant regarding physical properties,showing nanotubes as being very successful for enhancing tensile properties.