Immobilization of Polymethyl Methacrylate Brushes on Hydroxyapatite under Molecular Weight Control

Polymethyl methacrylate (PMMA) brushes with a quantitative molecular weight (M(w)) and low polydispersity index are synthesized via atom transfer radical polymerization and grafted onto the surfaces of hydroxyapatite (HA) that were modified with gamma-methacryloxypropyl trimethoxysilane (MPTS). The structure and morphology of MPTS surface modified and furthermore PMMA grafted HA was mainly investigated by means of infrared spectrophotometry, X-ray diffraction, thermal gravimetric analysis, scanning electron microscope, and differential scanning calorimetry studies. It is found that polymer brushes are covalently attached to the HA surface under controlled M(w) of PMMA segments without any structural deformation on the HA phase and exhibit grafting abilities for tuning properties of the composites.