Hydroxyapatite/polyurea nanocomposite: Preparation and multiple performance enhancements

In order to obtain polyurea (PUA) with better mechanical properties, hydroxyapatite (HAP)/PUA nanocomposites were prepared by the in-situ polymerization of polycarbodimide modified diphenylmethane diisocyanate (MDI-100L) covalently connected onto the HAP and Poly(tetramethylene oxide-di-p-aminobenzoate) (PTMO, P1000). The performance enhancements of nanocomposites were investigated through observing dispersion and interface interactions. As for the mechanical performance, tensile testing results indicated that the PUA/HAP nanocomposite with 0.2 wt% HAP nanorods exhibited improvements in tensile stress (52.4%). Scanning electron microscope (SEM), attenuated total reflection flourier transformed Infrared (ATR-FTIR) and X-ray diffraction (XRD) indicate that dispersion of HAP and the hydrogen bonds between the HAP nanorods and PUA are the significant factors for mechanical strength developing of PUA composites. Moreover, the self-stiffness of PUA was effectively suppressed by the incorporated HAP nanorods and decreased with the increase of HAP contents. Therefore, herein we provide useful information for the development of PUA/HAP composites.