A new approach for synthesis of the comb-shaped poly (ε-caprolactone) brushes on the surface of nano-hydroxyapatite by combination of ATRP and ROP

A facile strategy for growing the comb-shaped poly (ε-caprolactone) brushes on the surface of nano-hydroxyapatite (n-HAP) by combination of atom transfer radical polymerization (ATRP) and ring-opening polymerization (ROP) would be presented. Firstly, ATRP was used to graft poly (2-hydroxyethyl methacrylate) (PHEMA) onto the n-HAP surface. Then, the hydroxyl groups introduced onto the n-HAP were used to initiate the ROP of ε-caprolactone for constructing comb-shaped polymer brushes on the surface of n-HAP. The surface modified n-HAP was characterized by Fourier transform infrared (FT-IR) spectra, 13C solid-state cross-polarization magic-angle-spinning (13C CP/MAS), and thermal gravimetric analysis (TGA), X-ray diffraction (XRD), and transmission electron microscopy (TEM) measurements, respectively. The results demonstrated that the comb-shaped poly (ε-caprolactone) brushes had been grafted successfully, and the grafting ratio could be controlled well by adjusting the feed ratio of initiator and monomer.

Graphical abstractBIBB was coupled to hydroxyapatite to obtain ATRP initiator. It was used to initiate the ATRP of HEMA. Finally, the PCL brushes were grafted onto HAP surface.Figure optionsDownload full-size imageDownload high-quality image (100 K)Download as PowerPoint slideResearch highlights► BIBB was coupled to hydroxyapatite to obtain ATRP initiator. ► ATRP was used to graft PHEMA onto the n-HAP surface. ► The comb-shaped PCL brushes were grafted onto HAP surface by ROP.