Synthesis and characterization of basalt/bamboo fiber and chitin biopolymer toughened epoxy biocomposite for human prosthetic applications

This study examines the mechanical properties, water absorption, void content, thermal stability, drop load impact resistance, drilling performance and dynamic mechanical analysis (DMA) of composite materials made with echinoidea testa chitin macromolecule (ETCM) and hybrid basalt–bamboo fiber (BEBF). Its potential for use in prosthetic applications is evaluated. At first, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were used to check the composite’s thermal stability. The resistance to thermal deterioration was shown to improve as the concentration of ETCM rose, as evidenced by higher glass transition temperatures and early decomposition temperatures. The composite specimen denoted as EBT3 containing 4 vol.% of chitin showed a tensile strength of 155 MPa, flexural strength of 193 MPa, compression strength of 178 MPa, impact strength of 4.61 kJ/m², hardness of 89 Shore-D, initial decomposition % of 96 at 397 °C, water absorption of 1.38%, void percentage of 2.58%, energy absorption of 17.54 J, storage modulus of 6.9 GPa, loss factor of 0.58 and drilling diameter of 5.085 mm for 5 mm top drill diameter and 10.11 mm for 10 mm top drill diameter. The addition of chitin at 4 vol.% effectively filled microscopic voids and defects within the composite matrix, leading to a denser microstructure and reduced water absorption. SEM analysis unveiled substantial microstructural alterations, illustrating varied interfacial bonding and filler distribution within the composite matrix. Enhanced matrix–fiber adhesion and minimized voids were observed, contributing to improved mechanical integrity. However, agglomerated filler particles were detected at higher concentrations, potentially impacting material homogeneity and stress distribution.