Abstract
Metallic biomaterials are utilized in artificial hard tissues for medical applications. However, the Young's moduli of conventional metallic biomaterials are much higher than those of hard tissues. Thus, metallic biomaterials are required to have low Young's moduli, similar to those of hard tissues. Porous metallic materials, in comparison to bulk materials, are expected to exhibit lower Young's moduli; however, certain mechanical properties of porous materials decrease with an increase in their porosity. A polymer filling is a likely option to improve the mechanical properties of these porous metallic materials by preventing the stress concentration at the pore necks. Thus, in this study, the pores in porous pure titanium were filled with a medical polymer (polymethylmethacrylate: PMMA). Both pure titanium and PMMA are used in practical biomedical applications. The porous pure titanium/PMMA composite was fabricated by a simple process as follows. The air in the pores of a sintered compact of gas-atomized pure titanium powder (porous pure titanium) was removed by soaking the compact in a methylmethacrylate (MMA) monomer solution mixed with 2,2'-azobisisobutyrylnitrile (AIBN) as a polymerization initiator under reduced pressure at room temperature. Next, polymerization was carried out by heating to a constant temperature. The conditions of porous pure titanium (powder size, porosity, etc.) were systematically changed, after which the effects of the polymer filling on the mechanical properties of the porous pure titanium were investigated.
