Abstract
A novel microencapsulated intumescent flame retardant (TMAPP) was prepared, in which ammonium polyphosphate (APP) is the core and functions as an acid source, melamine-urea formaldehyde (MUF) resin is in the intermediate layer and functions as a blowing agent, and ferric tannin (mimicking mussel) is in the outermost shell layer and functions as a carbonization agent and also as a smoke inhibitor and surface modifier. TMAPP was prepared by treating MUF-microencapsulated APP with tannin acid and FeCl(3). Its structure is characterized by Fourier transform infrared, elemental analysis, and thermogravimetry (TG). TMAPP in epoxy was evaluated for its effect on flame retardancy and mechanical properties. The flame-retardant and smoke suppression performances of EP/TMAPP were studied using cone calorimetry (CONE) and limit oxygen index, and the flame-retardant mechanism was investigated by scanning electron microscopy and TG. The resultant data indicate that EP/TMAPP has very good mechanical properties, flame retardancy, and smoke suppression, whose char residue and thermal stability are increased, and the initial decomposition temperatures are decreased. Meanwhile, the char residue structures were very intumescent and compact. The char residue effectively prevents the underlying materials of EP/TMAPP from further combustion.