Thermoset powder coating films have been prepared from commercial hydroxy-functional polyester resins (PE) by crosslinking with toluene sulfonamide-modified melamine formaldehyde crosslinkers (TS-MF). Solvent resistance, hardness and impact resistance determinations have been made on films cured over a wide range of temperatures and with numerous variations in composition and characteristics of PE and TS-MF components. Cure behavior, as revealed by these 'property profiles', is discussed in terms of component structures and curing reactions. Selected films from property-profile studies have been characterized by dynamic mechanical analysis (DMA). Properties are compared for solvent-applied and powder-applied films prepared from the same compositions. Unexpected and potentially important new findings are reported on catalysis and pigment reinforcement. Crosslink densities from DMA and theory are compared.
