Grafting of Polycaprolactone on the surface of Hydroxyapatite via Silanisation

Hydroxyapatite (HAp) is the most commonly used calcium phosphate in the medical field such as bone filling, coatings of metallic implants, and scaffolds for tissue engineering due to its similarity to biological apatite, excellent biocompatibility and osteoconductivity. Mainly, surface modification enables to enhance solubility and stability of nanostructured materials in aqueous medias and/or to bring new materials functions and properties. In this study, Grafting of Polycaprolactone (PCL) on the surface of HAP modified beforehand with a mixture of TEOS-APTES was carried out by Ring Opening Polymerization (ROP). This latter was conducted under nitrogen at 130°C. The influence of the reaction time (24, 48 and 72 h) on the grafting amount of PCL was studied. FTIR-ATR, SEM and TGA were used to characterize our samples. FTIR-ATR analysis showed a new adsorption band at around 1725 cm-1 which is belonging to the carbonyl group of PCL. SEM analysis indicated a changing on the morphological of the powder both after silanization and grafting with PCL.TGA analysis indicated more important loss weight between 200 and 400 °C ,attributed to the degradadtion of PCL for the reaction conducted during 72h.