Desenvolvimento e caracterização de biocompósitos a base de amido de ervilha e fibra de macaúba, estudo das propriedades térmicas e morfológicas

Abstract

The world's great interest in reducing dependence on oil and global awareness of the environment serves as the starting point for the search for alternatives to conventional plastics derived from fossil sources. One of the alternatives is the use of materials made from polymers from renewable sources, such as starch, pectin, gelatin, natural fibers, among others. In order to approximate the characteristics of these polymers to those existing in conventional packages, several researches have been carried out such as the incorporation of antimicrobial agents, lipids to reduce the hydrophilicity of these materials, as well as, more recently, the use of nanoparticles to increase tensile and impact strength, among others. In this context, the objective of this work was to develop and characterize hybrid biocomposites based on pea starch, with the fiber addition of the residues of Acrocomia aculeata fruit popularly known as macaúba, by the thermoplastic extrusion process, to evaluate the viability of the processing, as well as the influence of the addition of these fibers (treated or not) to the pea starch-based composites. The pea starch was characterized in relation to the RVA and the microstructure and the fibers in relation to Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), where we observed the crus of malt and oval granules Thermogravimetric Analysis (TGA) and X-ray Diffraction (XRD). It was possible to add up to 3% fiber and 25% glycerol as plasticizer in the thermoplastic extrusion process. The obtained biocomposites were characterized when processability and color, structural, thermal properties and fire behavior. It was possible to incorporate up to 3% of fibers (crude or treated) in the polymer matrix under the conditions studied. There was a difference in the colorimetric profile of the extruded materials. Addition of fibers generally resulted in increased crystallinity of the material as well as an increase in the glass transition temperature of the studied biocomposites. It can be verified that the presence of 1.5 or 3% crude macauba fiber reduced the rate of heat release in the calorimeter cone tests.