Surface modification of bioceramics by grafting of tailored allyl phosphonic acid

Abstract

A new route to interfacial bonding between ceramic and matrix in biocomposites is identified. A tailored allyl phosphonic acid is used as a coupling agent bound to the surface of a bioceramic to form a 'grafted' calcium phosphate (CAP). The allyl phosphonic acid coupling agent is synthesised by reaction of allyl halide and trialkyl phosphite. Successful synthesis was confirmed by nuclear magnetic resonance and Fourier transform infrared spectroscopy (FTIR). The allyl phosphonic acid was incorporated onto calcium phosphate using a wet chemical coprecipitation synthesis route. The resulting 'grafted' CAP was characterised using FTIR coupled with photoacoustic sampling, and Fourier transform Raman spectroscopy (FTR). The spectroscopic data suggest an interaction between the allyl phosphonic acid and calcium phosphate resulting from observed reductions in intensity of the hydroxyl (3570 cm 21 ) and phosphate n 3 (1030 cm 21 ) peaks. The continued presence of C5C functionality on the surface of the grafted CAP was indicated by FTIR and FTR spectra (peaks at 1650 and 1635 cm 21 respectively) and confirmed by X-ray photoelectron spectroscopy (XPS). On the basis of these results, it is concluded that grafted CAP may be used to produce a chemically bonded composite with superior mechanical properties.

The influence of coupling agents on mechanical property retention and long-term cytocompatibility of phosphate glass fibre reinforced PLA composites

“…Similarly, 5 wt% HEMA-treated PGF/PCL composites had a flexural strength of 66 MPa, modulus of 2.5 GPa, an improvement of 14 MPa and 0.6 GPa compared to control (flexural strength of 52 MPa, modulus of 1.9 GPa) (Khan et al, 2009). Coupling agents investigated include, but are not limited to; conventional silanes (DiBenedetto, 2001;Park and Jin, 2003;Yazdani et al, 2006), various phosphonic acids (Greish and Brown, 2001a,b;Phillips et al, 2005;Tanaka et al, 2004), poly-(HEMA) (Brauer et al, 2008;Khan et al, 2009), zirconate, and titanate coupling agents (Bajaj et al, 1989;Pushpa et al, 1989). Recently, PLA oligomers with various end-functionalities were fabricated and showed promising results in terms of improving adhesion strength between glass fibre and polymer matrix (Haque et al, 2010a(Haque et al, , 2010b.…”

Hybrid Nanoparticles Prepared by In-situ and Post-synthetic Surface Modification of Lanthanide-Based Nanoparticles with Phosphonic Acid Derivatives

“…Figure 1 displays AFM and TEM images of typical samples based on APAiP as ligand and Nd(NO 3 ) 3 and YbCl 3 as lanthanide source, respectively. UV/Visspectroscopic measurements (not shown) have revealed that the PA alkyl esters cause a shift of some of the lanthanides' electronic transitions indicating a coordination of the ions by the PA ester in solution.…”

“…The modification can be used to improve the particles' solubility by preventing agglomeration [1]. For prosthetic materials Phillips et al used allylphosphonic acid as coupling agent between ceramics and a matrix [3]. For prosthetic materials Phillips et al used allylphosphonic acid as coupling agent between ceramics and a matrix [3].…”

UV-polymerisable, phosphorus-containing, flame-retardant surface coatings for glass fibre-reinforced epoxy composites

“…From Fig. 2(b), the characteristic peaks of VPA monomer can be identified as: bands at 1040-890 cm −1 : a symmetric stretching vibrations of P OH group; 1115 cm −1 : P O stretching of the phosphonic acid; 1405 cm −1 : vinyl C H in plane bending; 1614 cm −1 : C C band of the vinyl phosphonic acid and broad bands with medium intensity at 2850-2750 and 2500-2300 cm −1 : P O H group [18][19][20]. In Fig.…”