Bioceramics are primarily used as bone substitute materials in modern health care industries due to their low density, chemical
stability, high wear resistance and compositional similarities with human bone. Among various ceramics that have been tested for their use in the human body, calcium phosphate based materials are most favored by the scientific community because of their excellent biocompatibility and compositional similarities with human bone. Calcium phosphates exist in different phases depending on temperature, impurities and the presence of water. Two phases that are stable at body temperature are dicalcium phosphate and
hydroxyapatite (HAp). Hydroxyapatite, Ca10(PO4)6(OH)2 is an attractive bioactive ceramic widely used in hard tissue replacement surgery in view of its closeness with the mineral composition of natural bone. HAp can be produced either in dense or porous formed. Dense HAp can be used for prosthesis (hip) joint implant especially in parts that needs higher strength whilst the porous HAp can be used to replace any damages of human bone tissue. This paper was carried out to study the effect of
acrylamide and polyvinyl alcohol binders to the microstructural changes of HAp. This is achieved by a study on the effects of these binders on the porosity when the specimens were sintered to five different temperatures (1150°C, 1200°C, 1250°C, 1300°C and 1350°C) i.e acrylamide and polyvinyl alcohol 22000 (PVA 22000). The percentages of these binders being added were 60 % by weight of hydroxyapatite. Hydroxyapatite without binders was used as a reference specimen. The results indicated that the specimens which contains polyvinyl alcohol 22000 shows the highest value of porosity with 51.46% compared to Hap using acrylamide and without binders.