Obtenção e caracterização de compósitos sustentáveis de polietileno verde reforçados com casca de ovos e bio-CaCO3

Abstract

Polymers are consolidated materials in several application areas, due to their excellent properties and low cost. Companies and researchers are adhering to the idea about environmental awareness and producing sustainable materials, such as the green polyethylene I am greenTM. Composite materials were initially produced only with synthetic constituents, however, over the years, the range of studies changing the use of such materials by natural waste became visible, such as eggshells, which come from a highly consumable food and generate a large amount of waste rich in mineral salts. Thus, in order to contribute to the sustainable development, this work aimed to obtain, characterize and analyze composite materials made from low density green polyethylene (LDGPE), eggshells, and calcium carbonate. For that, the eggshells were collected and prepared for later extraction of calcium carbonate. The obtained powders were mixed with the polymer of interest by extrusion process and then molded via injection. The in natura and bio-CaCO3, particles were characterized by x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetry analysis (TGA), scanning electron microscopy (SEM) and laser dispersion granulometry. The LDGPE matrix and the composites were characterized for their mechanical properties (tensile test and Izod impact), thermal properties, through TGA and differential scanning calorimetry (DSC) and for structural and morphological analysis, scanning electron microscopy (SEM). At the end of the study, the results showed a significant increase in the Young's modulus of the composites compared to the pure polymer. This effect was more pronounced for the PEVBD/in natura system, where the increase in Young's modulus was approximately 124%. The SEM results showed good dispersion of the reinforcement materials in the matrix and good adhesion between the matrix and the reinforcement. Thus, both in natura and bio-CaCO3 particles can be used as reinforcement material in composites, where they act mainly on their stiffness and impact resistance. The composites produced in this research have strong competence to be applied in the packaging sector, where LDGPE is commonly used.