Abstract:
In this research, hydroxyapatite powder (HAp) was synthesized from chicken eggshell wastes by hydrothermal method.The effect of calcination temperatures on the properties of the synthesized HAp was investigated and, HAp filled high density polyethylene (HDPE) composites were developed by hot compression moulding machine using the HAp with the optimum quality. Chicken eggshells were gotten from local farm as a waste and were thoroughly washed and boiled in distilled water for 10 min to remove its inherent membranes. The cleaned shells were oven dried for 24 hours at 105oC, and thereafter divided into three parts to carry out a three-stage calcination treatment at , and , respectively in the furnace. Afterward, the calcined samples were separately dispersed in three beakers containing 100 ml of distilled water and orthophosphoric acid, and were subjected to vigorous stirring on a hot plate at 90 oC. Ageing treatment of the samples gave lumped white solids for each sample which were subsequently ground into powders. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive X-ray (EDX) spectrometer were employed to study the powder morphology, phase components and elemental composition, respectively. From the study, it was observed that the HAp synthesized at (HA1000) has a similar stoichiometry ratio (Ca/P = 1.65) with that of natural bone. More also, it has high tendency to agglomerate by creating pores required for body fluid circulation. Based on this, HA1000 was selected as reinforcing filler in HDPE matrix to develop composites. The composites were developed by random dispersion of HA1000 particles (10, 20,30 and 40 wt%) in HDPE matrix and were placed under the machine at for 15 min. Tensile, flexural, impact and wear moulds were used to get the sets of ASTM standards for the composite samples. The samples were also tested for fracture toughness and hydrophilicity using tap water and simulated body fluid (SBF). The results obtained showed that the mechanical properties of composite samples were significantly enhanced compared to control HDPE sample. Samples with 40 wt% HA1000 particles exhibited the best flexural strength, yield strength, Young’s modulus and wear resistance properties while sample from 20 wt% above had the best fracture toughness. Hydrophilic property of the composite samples was improved in SBF solution without degradation whereas there was mass loss after about 72 hrs of immersion in tap water.It is clear from the results of this study that the developed composite samples can be applied as biomedical implant to support bone reformation.
