Mechanical Properties, Viscoelastic and Water Absorption Properties of Biocarbon-Reinforced Composites

Biocarbon-reinforced polymer composites have emerged as a sustainable alternative to conventional composites, combining environmental benefits with promising material properties. This study explores the effect of varying biocarbon content (0%, 10%, 20%, and 30% by weight) on the mechanical, viscoelastic, and water absorption properties of a polypropylene (PP) matrix. Tensile strength tests reveal that incorporating 10% biocarbon yields the highest strength at 35 MPa, attributed to enhanced interfacial bonding. However, at higher loadings, tensile strength diminishes due to particle agglomeration and reduced stress transfer efficiency. Flexural strength, on the other hand, increases steadily with biocarbon content, peaking at 50 MPa for 20% loading before plateauing, making it suitable for load-bearing applications Impact strength decreases with increasing biocarbon addition, highlighting a trade-off between stiffness and toughness. Dynamic Mechanical Analysis (DMA) demonstrates that higher filler content enhances the storage modulus and thermal stability, indicating improved rigidity and heat resistance. However, the addition of biocarbon also significantly increases moisture uptake, particularly beyond 20% loading, as observed in water absorption tests. This heightened moisture sensitivity underscores the necessity for surface treatments or hydrophobic modifications to extend the composite’s applicability to outdoor or humid environments. These findings provide critical insights into optimizing biocarbon content for structural applications, balancing mechanical performance with environmental sustainability, and addressing moisture-related limitations for broader usage in various industries.