DEMONSTRATION OF METHYLENE-ETHER BRIDGE FORMATION IN MELAMINE-FORMALDEHYDE RESINS

H-1 and C-13 NMR have been used for the quantitative determination of methylene-ether bridges in melamine-formaldehyde (MF) resins. The amou nt of methylene-ether bridges was determined by C-13 NMR from the numb er of monomethylolated amino groups consumed in the condensation react ions and is in agreement with that calculated from the condensation wa ter contents. This latter method, which involves a combination of H-1 and C-13 NMR, is based on the amount of condensation water released du ring the formation of both methylene and methylene-ether bridges. (C) 1995 John Wiley and Sons, Inc.