Polymerizable Phosphonic Acids

The following chapters are devoted to applications of phosphorus-based materials. Thus Chapter 8 by Mozsner and Catel deals with the use of polymerizable phosphonic acids (PAs) and dihydrogen phosphates (DHPs) for dental applications. Several PAs and DHPs were synthesized to notably improve the shear bond strength to dentin and enamel, the stability of the adhesive formulation, and the chemical adhesion to tooth tissues. Some of these monomers are nowadays included in commercial dental adhesives. 

Acidic monomers could be phosphates as well as carboxylic, sulfonic, or phosphonic acids. Some examples of carboxylic acid monomethactylates are 4-(2-methactyloyloxyethyl)trimellitic acid (4-MET) and 11-methactyloyloxy-1,1-undecanedicarboxylic acid (MAC-10). Among the functionalized monomers, free-radically polymerizable phosphonic acids (PAs) and dihydrogen phosphates (DHPs) have found wide and intensive applications as adhesive components in enamel/dentin adhesives. In this chapter, a review of the various PAs and DHPs prepared for application in dental adhesives is provided. 

Photopolymerization of phosphorus-based (meth)acrylic monomers was largely investigated for dental applications (Scheme 1.4) 20,21,56 69 monomers bore one or two polymerizable groups and phosphoric acid ester, phosphonate, and phosphonic acid moieties were evaluated. When the phosphorus atom was directly linked to a hydrocarbon chain phosphonate ester), the monomers were more resistant to hydrolysis in comparison with phosphoric acid esters. 

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