Monomers for adhesive polymers, 17.^aSynthesis, photopolymerization and adhesive properties of polymerizable phosphonic acids bearing urea groups

Abstract

Four polymerizable phosphonic acids bearing urea groups 4a, 4b, 9a, and 9b as well as the 10-(methacryloyloxy)decylphosphonic acid 10 were synthesized in four to six steps. They were characterized by 1 H, 13 C, and 31 P NMR spectroscopy and by high-resolution mass spectroscopy. Contrary to methacrylates 4a and 4b, methacrylamides 9a and 9b were hydrolytically stable in deuterated water/deuterated ethanol solutions. The photopolymerization behavior of acidic monomers 4a, 4b, 9a, 9b, and 10 and their corresponding phosphonates were studied using a differential scanning calorimeter. Homopolymerizations and copolymerizations with N-butyl-N-ethylacrylamide were carried out. The presence of a urea group was found to significantly increase the rate of polymerization. Monomers bearing a phosphonic acid group were more reactive than their corresponding phosphonates. Self-etch adhesives based on monomers 4a, 4b, 9a, and 9b were able to provide a strong bond between a composite and the dental hard tissues (dentin and enamel). The presence of a urea group led to a significant increase in the shear bond strength to both dentin and enamel.

Urea dimethacrylates functionalized with bisphosphonate/bisphosphonic acid for improved dental materials

“…They were found to be more reactive than TEGDMA due to a combination of hydrogen abstraction/chain transfer reactions via the labile hydrogens and hydrogen bonding caused by the urea linkage. Moszner et al described the synthesis of polymerizable phosphonic acids bearing urea groups and showed that the presence of urea group led to a significant increase in both rate of polymerization and shear bond strength to dental tissues …”

Synthesis and photopolymerizations of first monomers with phosphonate and bisphosphonate or phosphonic and bisphosphonic acid functionalities for potential dental applications

“…These monofunctional methacrylates with enhanced rates and conversions were found to have potential to be used as diluent monomers in dental formulations. Then, phosphonic acids bearing urea groups were synthesized to improve the performance of self‐etching adhesives by Moszner and coworkers and the presence of a urea group was shown to significantly increase both the rate of polymerization and the shear bond strength to both dentin and enamel …”

Monomers for adhesive polymers, 18. Synthesis, photopolymerization and adhesive properties of polymerizable α-phosphonooxy phosphonic acids

“…Therefore, acidic monomers exhibiting strong chelating properties were synthesized and tested in SEAs. It has been demonstrated that the adhesion of SEAs can be improved when polymerizable diphosphonic acids,[ 10–12 ] β-ketophosphonic acids [ 13 ] or phosphonic acids bearing urea groups [ 14 ] are used as acidic monomer. Gem-phosphonate-phosphates were found to be potential antiatherosclerotic agents.…”