C-13-NMR STUDIES OF COMMERCIAL AND PARTIALLY SELF-CONDENSED HEXAKIS(METHOXYMETHYL)MELAMINE (HMMM) RESINS

C-13-nuclear magnetic resonance (NMR) spectroscopy was employed to stu dy the linkages in three commercial fully methylolated melamine-formal dehyde (HMMM) resins and their partially self-condensed resins by acid catalysis, in order to probe the structures linking melamine units. D istortionless enhancement by polarization transfer (DEPT) experiments show that the partially self-condensed resins contain both methylene e ther (drop NCH2OCH2N drop) and methylene (drop NCH2N drop) linkages be tween melamine units. The extent of these linkages were estimated by q uantitative C-13-NMR spectroscopy using inverse gated decoupling techn iques. The results show that the ratios of methylene ether and methyle ne linkages to the triazine moiety vary from resin to resin. (C) 1996 John Wiley & Sons, Inc.