Hydrolytic stability of methacrylamide in acidic aqueous solution.

In order to develop a more effective self-etching primer, with a longer lasting shelf life, we designed a self-etching primer comprised of methacrylamide, N-methacryloyl glycine, NMGly. In this study, the hydrolytic stability of the amide portion in the NMGly was examined. The difference in the hydrolytic stability between the methacrylamide and the methacrylate, 2-hydroxyethyl methacrylate, HEMA was then discussed. The addition of an acid to an aqueous solution allows for the hydrolysis of the ester portion in the methacrylate and for the production of methacrylic acid, MA and ethylene glycol, EG. From our study, the data clearly demonstrated that, if the storage duration of a commercially available self-etching primer is prolonged, then the functional methacrylates constituting the self-etching primer will be altered upon use. However, the hydrolytic stability of the amide portion in the methacrylamide, NMGly, designed as an acidic and/or hydrophilic monomer for the self-etching primer, was greater than the results achieved with the methacrylate, HEMA.