Synthesis and radical polymerization of hydrolytically stable dentin bonding agents

Acrylic groups containing phosphonic acids were synthesized by ether formation of ethyl α‐chloromethylacrylate with hydroxyalkyl phosphonates and subsequent hydrolysis to the corresponding phosphonic acid α‐methylsubstituted acrylates. Furthermore, phosphonic acids derived from acrylonitrile and acrylamide were synthesized. The monomers are hydrolytically stable in aqueous ethanol. The radical polymerization of the monofunctional phosphonic acids results in water soluble polymers, whereas in case of a phosphonic acid diacrylate a cross‐linked polymer was formed. The most radical polymerizable phosphonic acids can be used to promote the adhesion to dentin.