Morphological, barrier, and mechanical properties of banana starch films reinforced with cellulose nanoparticles from plantain rachis

The main aim of the present study was to characterize banana starch films reinforced with nanoparticles from plantain rachis. Nanoparticles were obtained by acid hydrolysis and sonication, exhibiting a mean hydraulic diameter of about 60 nm. Scanning electron microscopy micrographs showed that the nanoparticle thickness ranged between 9.8 and 22.3 nm. The thermal gravimetric analysis showed that nanoparticles are thermally stable for temperatures up to 340 °C. Films were made for different fractions of nanoparticles (0.0, 1.75, 2.5, and 4.0%) relative to total solids, and glycerol was used as a plasticizer. The influence of the addition of nanoparticles to starch films on the morphology, water vapor permeability (WVP), and mechanical properties of the nanocomposites films was explored. Cellulose nanoparticles reduced the WVP, and increased the tensile strength and flexibility of the starch films. FTIR analysis of films was used to show that nanoparticles improved the molecular organization of starch chains. It was proposed that nanoparticles acted as a crosslinked for starch chains via hydrogen bonding effects.