Evaluation of the tensile strength of polymer composites with natural fibers in different reinforcement architectures

ABSTRACT

Natural fibers stand out as sustainable alternatives for reinforcement in composites due to their availability, low cost, and reduced environmental impact. This research evaluated the mechanical behavior of polymer composites reinforced with jute fibers in the form of yarns, manufactured by manual lamination with unsaturated polyester resin as the matrix. Commercial fibers, in flat fabric (T), were manually shredded to form unidirectional arrangements with specific orientations, resulting in eight stacking configurations: 45°/ 0°/45°, 45°/45°/45°, 45°/90°/45°, 45°/T/45°, T/0°/T, T/45°/T, T/90°/T, and T/T/T. During the manufacture of the laminates, the mass fraction of fiber was kept constant at 18%, and curing was performed at room temperature for seven days. The samples were subjected to tensile tests according to the parameters of ASTM D3039/D3039M, with load application at 2 mm/min. The results showed significant variations in mechanical properties depending on the orientation of the fibers, with the T/0o/T and 45°/0°/45° arrangements showing the best performance in terms of tensile strength (31.19 MPa and 31.16 MPa, respectively). Surface fractography allowed the failure modes to be correlated with the architecture of the manufactured composites, emphasizing the influence of symmetry and the combination of aligned and woven fibers on the properties of the proposed materials.

Keywords:
Laminated composites; Polymeric matrix; Vegetable fibers; Tensile strength