Nitroxide‐Mediated Polymerization Synthesis of Geminal Bisphosphonate‐Functionalized (Co)polymers and Their Affinity to Hydroxyapatite Surface

ABSTRACT Geminal bisphosphonate‐functionalized (co)polymers are synthesized via nitroxide‐mediated polymerization (NMP) using gem ‐bisphosphonate‐functionalized vinylbenzyl monomer ( gem BP‐VB), which is first synthesized and fully characterized by 1 H, 13 C, and 31 P NMR as well as by mass spectroscopy. The NMP process yields (co)polymers with narrow dispersity ( Ɖ < 1.3). Subsequently, the gem BP ester groups in these (co)polymers are quantitatively converted into their corresponding bisphosphonic acid functionalities. The chelating ability of the resulting geminal bisphosphonic acid‐containing copolymer, composed of gem BP‐VB and poly(ethylene glycol) methyl ether methacrylate (mPEGMA), is evaluated through its adsorption onto hydroxyapatite (HAp) surfaces. Thermogravimetric analysis reveals an adsorption capacity of 0.105 mmol of phosphonic acid groups per gram of HAp, which exceeds literature values and highlights the potential interest of bisphosphonic‐functionalized (co)polymers in (bio)material applications.