Filmes biodegradáveis à base de amido de milho incorporados com celulose obtida a partir da coroa do abacaxi

Abstract

With the increasing degradation of the environment, there is a need to seek sustainable alternatives for the use of materials in a more conscious way. Therefore, this work aimed to develop biodegradable composites in the form of films based on corn starch, incorporated with cellulose extracted from the waste pineapple crown for application in packaging. First, cellulose was obtained through the pineapple crown by alkaline treatment followed by bleaching. Pineapple crown fibers and cellulose were characterized by thermogravimetric analysis (TGA), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR), from these analyzes it was possible to verify that the treatments were effective to isolate cellulose fibers. For the preparation of the films, they were produced by casting, which consisted of a filmforming solution from corn starch, glycerol and cellulose, added in different concentrations (5%, 10%, 15%), in addition to pure starch control film. No significant differences were found in the thickness and grammage values of the biocomposites in relation to the pure starch film. The biocomposites proved to be less soluble in water and the film with 15% cellulose showed less water vapor permeability in relation to the film of pure starch. Regarding the thermal characterization through DSC, there were no significant variations in the melting temperature and gelatinization temperature in the films. When analyzing the mechanical properties, it was seen that the elasticity module of the biocomposites increased in relation to the film without adding reinforcement, giving highlight for the composite with 15% reinforcement, with an increase of 377.76%. Regarding the tensile strength, there were no differences when adding reinforcement, possibly due to the dispersion of the fibers. Through the phytotoxicity test, it was possible to notice that the addition of the films to the soil does not negatively influence the germination and growth of lettuce seeds (Lactuca sativa). Regarding biodegradation, the films were completely degraded after 60 days of experiment. FTIR analysis after degradation showed no changes in the spectra. From the elaborated films, it is possible to highlight the biocomposite containing 15% cellulose, as it showed an increase in the elasticity module, better results of barrier properties and rapid initial biodegradation. This material demonstrates great capacity to be applied in packages of quick use.