Characterization of animal shells-derived hydroxyapatite reinforced epoxy bio-composites

Environmental issues have geared the interest of researchers toward the use of naturally occurring materials for various applications in recent times. Hydroxyapatite particles (HAp) for biomedical applications were synthesized from egg and snail shells and used for the fabrication of bio-composites in this research. The shells were prepared by thoroughly cleaning before subjecting to calcination as well as wet-chemical precipitation treatment to obtain 50 µ sized hydroxyapatite particles that were used for the development of the bio-composites. The composites were fabricated with an open mold stir casting technique after mixing the constituents in predetermined proportions. Mechanical, wear, and physical properties evaluations were carried out on the composites and control samples while the images of the fractured surfaces were examined using a scanning electron microscope. It was revealed from the results that the addition of hydroxyapatite to epoxy improved the properties of the composite where most of the optimal values emerged from 15 wt% HAp-reinforced samples. It was discovered that snail shell HAp-based composites had superior enhancements than the eggshell HAp-based composites which showed that the source of the animal shell influences the characteristics of the ensuing properties. Flexural strength and modulus were 63.95 and 774.64 MPa, respectively; hardness was 40.25 HS, wear index was 0.07, and thermal conductivity was 0.545 W/mK for the snail shell HAp-based composites. Hence, synthesized HAp from snail shells is more structurally stable than eggshell-based and can be used for biomedical applications.