Eco‐friendly PLA biocomposites with teasel gourd stem fiber and activated biocarbon from palm kernel shells using 3D printing technology

PLA-based biocomposites were developed and characterized for fatigue, creep resistance, thermal conductivity, and hydrolytic stability. The result outcomes revealed that the fatigue performance showed a significant enhancement with the incorporation of fiber, with the best result observed for the composite PGB4 (4 vol.% biocarbon), which exhibited higher fatigue cycles up to 26,441 at 25% ultimate tensile stress. In contrast, the creep, thermal conductivity, swelling, and degradation showed best results for the composite PGB5 (8 vol.% biocarbon). Composite PGB5 recorded a lowest creep strain values and a highest thermal conductivity (0.60 W/mK) and the lowest swelling (0.580 to 2.100 from Week 1 to Week 4) and degradation (0.11 to 0.579) over 4 weeks. SEM microstructural analysis further supported these findings, where PGB4 revealed strong fiber–matrix bonding and efficient filler dispersion, while PGB5 exhibited compact microstructural packing with fewer voids and well-embedded filler particles. Overall, biocarbon content strongly influences both mechanical durability and long-term stability, with PGB4 being suitable for cyclic load-bearing components such as lightweight mechanical parts, orthotic shells, and consumer product housings, and PGB5 being more suitable for thermal management and moisture-sensitive applications such as electronic casings, heat-dissipating panels, and indoor construction materials.