The storage stability of melamine formaldehyde resin solutions: III. Storage at elevated temperatures

The possibility of storage of melamine formaldehyde (MF) resin solutions at elevated temperatures is examined. A series of MF resin solutions with var ious formulations were synthesised and storage stability was studied at roo m temperature and 50 degrees C. In general, the stability at 50 degrees C w as higher over a much broader range of reaction times when compared with st orage stability at room temperature. The storage of MF resin solutions at e levated temperatures offers many advantages like the ease of resin producti on on large scale and high reproducibility of storage stability. Further, i t is shown, by means of C-13-NMR and light scattering analysis, that the ch emical structure and molecular weight are identical at the point of instabi lity at 50 degrees C irrespective of the initial degree of condensation i.e , reaction time. (C) 1999 Elsevier Science Ltd. All rights reserved.