<i>Hibiscus sabdariffa</i> L. Fiber (HSF) Rope Mat/Wood Sawdust Filler Polyester Composites for Potential Biomedical Structural Application: Mechanical and Thermal Characteristics

The possible biomedical uses of rope mat reinforced polyester composites using Hibiscus sabdariffa L. fiber (HSF) and wood sawdust are the focus of this investigation. By utilizing compression molding, six different composite versions were created. These variants included both single-layer and double-layer HSF rope mats with vertical fiber orientations. Mechanical parameters such as hardness, tensile strength, flexural strength, and free vibration response were measured, in addition to thermal stability and free vibration response. Evaluation of fiber-matrix adhesion was carried out using scanning electron microscopy (SEM). Barcol hardness = 46, tensile strength = 100 MPa, impact strength = 146 MPa, and flexural strength = 372 MPa were all achieved by the double-layer vertical fiber orientation with sawdust filler, which also demonstrated the best performance. The better fiber-matrix bonding and mechanical interlocking caused by the sawdust filler are responsible for the enhanced characteristics. In addition to showing temperature resistance up to 72°C, the composite exhibited steady-free vibration behavior at a natural frequency of 76 Hz. These results indicate that HSF rope mat/wood sawdust filler polyester composites are a promising, sustainable alternative potential for biomedical structural applications requiring vibration damping, moderate strength, and thermal stability.