MASS-SPECTROMETRIC ANALYSIS OF POLYMERS DERIVED FROM N-ARYL-ALPHA-AMINO ACID INITIATORS

Previous studies have demonstrated that the interaction of carboxylic acids with aryl amines produces free radicals that can initiate the po lymerization of acrylic monomers. N-Aryl-alpha-amino acids (NAAA) repr esent a special class of this type of initiator that combines in one m olecule the carboxylic acid and aryl amine functionalities necessary f or the generation of radical species. The mechanism(s) of radical form ation in these molecules is thought to involve both electron transfer and hydrogen abstraction reactions that can occur by intra- and interm olecular pathways. Acrylic monomers, i.e., methyl methacrylate (MMA) a nd 2-hydroxyethyl methacrylate (HEMA), were activated with various amo unts of several NAAAs. Specific NAAAs investigated include N-phenylgly cine (NPG) and N-p-tolylglycine (NTG). Polymerization was conducted at ambient or near ambient temperatures, and the polymers then were anal yzed by electron impact mass spectrometry. Results indicate that these polymers have end groups derived directly from the NAAA initiators. ( C) 1997 John Wiley & Sons, Inc.