Physical, Chemical and Mechanical Characterization of Polypropylene Biocomposites with Fibers from Euterpe precatoria, Paullinia cupana var. sorbilis (mart.) ducke and Astrocaryum aculeatum

Resumo

The growing concern over the improper disposal of Amazonian fruit residues and the increasing demand
for sustainable materials motivated this study. This work aimed to develop biocomposites from açaí,
guaraná, and tucumã residues incorporated into a polypropylene (PP) matrix via injection molding. The
materials were produced and characterized by lignocellulosic analysis, X-ray diffraction (XRD), and
scanning electron microscopy (SEM). The fibers presented moisture content ≤ 22.4%, cellulose ≤ 50.9%,
hemicellulose ≤ 37.8%, lignin ≤ 45.7%, and crystallinity ≤ 28.4%. Thermal behavior, analyzed by
thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), revealed transformation
ranges of 167.8–464.0 °C for the biocomposites and 437.3 °C for neat PP, with degradation onset at 300
and 396.8 °C, respectively. Although the biocomposites exhibited lower tensile strength than neat PP,
mechanical testing (tensile and flexural) indicated distinct rupture patterns and phase separation. These
findings support the potential of Amazonian fruit residues as reinforcing agents in sustainable polymeric
materials with industrial applicability.