Journal of Applied Polymer Science, Vol.67, No.9, 1545-1551, 1998
A GC-MS study of the addition reaction of aryl amines with acrylic monomers
Previous studies have shown that the interaction of carboxylic acid groups with the amine functionalities of aryl amines, especially secondary and tertiary aryl amines, can lead to the free-radical polymerization of acrylic monomers such as methyl methacrylate. In this study, the Michael addition reaction of primary and secondary aryl amines with acrylic monomers such as acrylic acid (AA) was investigated. Equivalent amounts of either p-toluidine (PT) or N-phenylglycine (NPG) and AA were combined in polar solvents such as ethanol. The reactions were conducted at ambient (23 degrees C) or near-ambient (37-60 degrees C) temperatures. Samples (about 3-5 mg) of these products were then trimethylsilylated with a solution consisting of 0.4 mt of bis (trimethylsilyl) trifluoroacetamide (BSTFA) and 0.4 mt of acetonitrile by heating for 30 min at 140 degrees C under N-2. These derivatives were characterized by gas chromatography-mass spectrometry (CC-MS). The CC-MS analyses suggest that 1 mol of the primary amine PT had reacted with 2 mol of AA to yield the expected N-p-tolyliminodipropionic acid. Similarly, the secondary amine NPC added to 1 mol of AA. yielded the corresponding mixed iminodiacid, N-phenyliminoacetic-propionic acid. It would appear that the Michael reaction of primary and secondary amines with acrylic monomers may offer a general, facile synthetic route to a variety of tertiary amines. Aryl amino acids of the type synthesized in this study may find use in a number of dental applications, e.g., as surface-active adhesive agents and as polymerization initiators or activators.