Direct use of Brazilian banknotes residue for the production of reinforced composites based on low-density polyethylene

In this article, banknotes residues were used to prepare reinforced low-density polyethylene (LDPE) composites. First, the banknotes residues were crushed into fibers and then it was added in the polymeric matrix using different weight ratios (1-20 wt %). The composites were prepared by melt compounding, followed by injection molding. Afterward, the composites were characterized by scanning electron microscopy, contact angle, thermogravimetric analysis, Fourier transform infrared (FTIR) spectroscopy, and tensile tests. The FTIR showed physical interaction between fibers and the polymer matrix. In comparison with pure LDPE, improved mechanical properties were achieved for the composites containing 5-20 wt % of fibers (i.e., increase of 83% when 20% of fibers were used), with an increase in the tensile strength and Young's modulus, and a decrease in the elongation percentage. The results illustrate that the banknotes residues can be used for reinforcement of hydrophobic polymers without the need of any chemical modification or addition of compatibilizing agents. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48232.