Preparation and biotribological properties of PSBMA polyelectrolyte brush on PEEK surface

Abstract PEEK has been widely used in orthopedic implants for three decades. However, poor hydrophilicity and lower tribological properties are the weaknesses of PEEK that need to be optimized in artificial joint applications. Zwitterionic sulfobetaine methacrylate (SBMA) polyelectrolyte brushes are prepared on the PEEK surface by UV irradiation to improve the hydrophilicity and biotribological properties. The three‐factor and three‐level orthogonal experiments are designed to investigate the effects of monomer concentration, irradiation time, and temperature of the grafting quantity of SBMA on the PEEK surface. The composition of the grafted PEEK specimens is characterized by attenuated total reflection Fourier transform infrared spectroscopy (ATR‐FTIR) and X‐ray photoelectron spectroscopy (XPS). Hydrophilicity and biotribological properties are also characterized. Results show that SBMA is successfully grafted onto the PEEK surface by UV‐induced grafting polymerization, and the effects of the three process parameters on the grafting quantity are ranked as concentration > time > temperature. The hydrophilicity and biotribological properties are significantly improved due to the graft of the hydrophilic PSBMA polyelectrolyte brushes, and the improved biotribological can be attributed to the load‐bearing capacity of PSBMA polyelectrolyte brush and the boundary lubrication formed by the adsorption of water molecules.