Hybrids Obtained from Monoglyceride of Castor Oil with Hydroxyapatite for Applications in Bioinduction of Bone Tissue: Synthesis and Characterization

Abstract

In this paper, we report the initial research to obtain hybrids (PU@Hap-1%, PU@Hap-2% and PU@Hap-3% compound by hydroxyapatite (Hap) synthesized by coprecipitation (CP) method, with monoglycerides (MG) of castor oil (Ricinus communis) polymerized with hexamethylene diisocyanate (HDI). Hap, was characterized by X-ray diffraction (XRD), Rietveld refinement, Fourier transform infrared (FTIR), RAMAN spectroscopy and X-ray fluorescence (XRF). Hybrids, MG and castor oil, were characterized by Fourier transform infrared (FTIR). XRD patterns and Rietveld refinement analysis confirmed that hexagonal phase for nanostructure for Hap, with average size particles D  12 nm, obtained by Scherrer equation and ration Ca/P = 2.13 (m/m) confirmed that XRF spectroscopy. FTIR and RAMAN spectra exhibited all active modes for vibrational stretches (1, 2, 3 and 4) of the phosphate groups () and vibrational modes of O-H bonds, present in the hexagonal structure for Hap in a ranger from 400 to 4000 cm-1 and 400 to 1100 cm-1, respectively. The conversion of castor oil (triglyceride) to MG, was monitored by FTIR spectroscopy, confirmed that increase of intensity active modes in 3317 cm-1 and 1741 cm-1, corresponding to the vibrations modes of O-H and C=O, respectively. Finally, we observed that all active modes in FTIR spectroscopy, corresponding to the hybrids: PU@Hap-1%, PU@Hap-2% and PU@Hap-3%, and Polyurethanes – PU (standard), confirmed the increase of intensity mode of the phosphate group with the increase of Hap in the polymerization of the mixture MG with HDI.