Structural and Bioactivity Studies of Nanostructure Hydroxyapatite-Nylon 6,6 Composites Using Sol-Gel Method

An interfacial polymerization method for nylon 6,6 was adapted to produce nanostructured composites with nano hydroxyapatite (n-HA) via in situ polymerization. Nylon 6,6 was synthesized with hexamethylenediamine and adipoyl chloride viainterfacial polymerization method in n-HA slurry to increase homogeneity and biocompatibility. Then as synthesis powders with 60% n-HA content was dried in 80º and was characterized by x-ray diffraction analysis (XRD), transmission electron microscopy(TEM), thermogravimetric analysis (TGA) and FT-IR analysis. The results showed a uniform dispersion in composites, whereas needle-like n-HA crystals dispersed in condense polymer matrix. Infrared spectrum results showed that n-HA and nylon 6,6 were mainly linked by hydrogen-bonding, which mainly existed between OH of n-HA and amide of nylon 6,6. The X-ray diffraction results verified the presence of all characteristic peaks n-HA and nylon 6,6 in composite powder. The evaluation of mechanical properties of the composite powder approved their accordance to natural bone. The samples were immersed in simulated body fluid (SBF) for bioactivity tests in different periods and results were compared with scanning electron microscopy (SEM) in terms of forming apatite layer.