Performance of MUF resins for particleboard before and after spray-drying

摘要

Melamine-urea-formaldehyde (MUF) resins can be spray dried to obtain resins in powder form and indefinite shelf-life. Application as particleboard adhesives of such resins after redissolving in water yield resins of excellent performance as particleboard adhesives if the natural advancement caused by the heat in the spray-drier chamber is taken into account. Solid-state cross-polarization/magic angle spinning ~(13)C nuclear magnetic resonance (CP-MAS ~(13)C NMR) analysis of the spray-dried resin in powder form and thermomechani-cal analysis (TMA) has shown some difference in behavior in relation to MUF resins of the same level of water tolerance which have not been spray-dried. These small but significant differences can be ascribed to differences in resin structure.