Produção e caracterização de filmes biodegradáveis de amido de milho regular e ceroso reforçados com nanocelulose de eucalipto

Abstract

Biodegradable films are currently being studied to provide an alternative renewable source material that does not harm the environment as with petroleum-based plastic waste. Maize starch stands out for its immense potential to form a continuous matrix, being inexpensive and widely available in nature. Eucalyptus nanocellulose also being a highly available and renewable source as well as reinforcing maintains the biodegradability characteristics of composites. In this study, films based on two polysaccharides, regular maize starch and waxy maize starch, were produced by casting technique and nanostructured with eucalyptus nanocellulose at the following concentrations: 0, 0.5, 1 and 1.5% in 7g of polymer using glycerol as plasticizer.The characterization of the raw materials were analyzed, regular maize: 27% amylose content; 7.4J/g gelatinization enthalpy; 33.43% relative crystallinity; waxy maize: 0.78% amylose content; 11.4J/g gelatinization enthalpy; 37.68% relative crystallinity.The particle size and surface charge of the nanoparticles were 14.24nm and -23.10mV, respectively. Moisture susceptibility, water solubility and water vapor permeability for both films improved with the addition of reinforcement. Regarding mechanical properties, the incorporation of nanofibers increased the tensile strength of the films, while the elongation at break showed a reduction for both types of films. Comparing the polymeric matrices, regular maize starch showed a better response to nanoparticle incorporation due to polymer-nanoparticle interactions, differences confirmed by mechanical properties, moisture susceptibility, water solubility and water vapor permeability. This research suggests application in food packaging as a biodegradable alternative of providing the film with properties for the protection, maintenance and quality of food.