Bioresin-based composites reinforced with natural fibers and carbon fiber: Mechanical properties and sustainable benefit assessment

This study explores the development of bioresin-based fiber-reinforced polymer (FRP) composites, incorporating natural fibers and carbon fiber for comparison purposes. The primary objective is to examine the effects of different fiber types, bioresin compositions, and temperature exposures on the tensile properties of biopolymer-based FRP composites. Four fiber types were tested, including three natural fibers (jute, sisal, and water hyacinth) and carbon fiber. Two biopolymer resins were used: BR29 (29 % bio-content) and BR97 (97 % bio-content). Uniaxial tensile tests were performed on FRP coupon specimens at three different temperatures (25, 40, and 55 °C) to evaluate variations in tensile stress-strain behavior and strength characteristics. The results showed that FRP composites made with BR29 consistently exhibited higher tensile strength than those made with BR97, across all fiber types and all temperatures. This was particularly evident in natural fiber composites, where BR97 caused voids at the fiber-resin interface, weakening the material. Among the tested composites, jute FRP with BR29 demonstrated the highest tensile strength and elastic modulus. Additionally, both carbon and water hyacinth FRP composites with BR29 displayed minimal sensitivity to temperatures up to 55 °C. Despite this, BR97 was found to be suitable for carbon FRP, as it did not significantly reduce tensile strength with increasing temperatures. While carbon FRP composites had the highest CO₂ emissions per unit area, natural FRPs offered a carbon footprint reduction of up to 88.6 %, making them a more sustainable choice for green construction. © 2025 The Authors.