Intrinsically flame retarded foams based on melamine − formaldehyde condensates: thermal and mechanical properties

Two kinds of foam based on melamine − formaldehyde (MF) condensates (PVA/MF (PVA, polyvinyl alcohol), PVA/APTES/MF (APTES, 3-triethoxysilylpropylamine)) were prepared by chemical modification. Pure MF foam has the serious disadvantage that it is very hard and brittle, breaks easily and crumbles when handled. After modification, PVA/MF and PVA/APTES/MF display excellent resilience. The structures of the foams were characterized by Fourier transform infrared (FTIR), SEM and XRD. XRD data indicate that modifiers hinder the crystallization of MF, which might contribute to the improvement of resilience. Flame retardancy of the foams was characterized by limiting oxygen index testing, and the thermal degradation behavior was studied using TGA. The mode of flame retardant action is suggested by gaseous and solid phase analysis. TGA-FTIR results demonstrate that the sublimation of the melamine of MF and foams based on MF occurs during thermal decomposition, which contributes to the high flame retardancy. © 2016 Society of Chemical Industry