Synergistic fire retardancy of melamine resin modified with pentaerythritol and ammonium polyphosphate in PP

The synergistic fire retardancy of modified melamine resin with pentaerythritol (MF-PER, a novel green and effective triazine charring agent), and ammonium polyphosphate (APP) in polypropylene was investigated by UL-94 test, LOI measurement, and cone calorimetry test. It is found that the synergism of MF-PER is obviously better than pentaerythritol (PER). MF-PER/APP imparts a fire retardancy mainly by the following mode: in burning process, MF-PER, and APP are first pyrolyzed respectively into polyols and polyphosphoric acid, which is esterified to form phosphoric ester, and the inert gases make the molten residues foaming; When the temperature increases, and polyphosphoric acid is dehydrated to polymetaphosphoric acid, which dehydrates phosphoric ester to form an intumescent char layer, inducing a fire retardant effect by barrier effect. The graphitization degree of the cone calorimetry test residues of the FR-PP with MF-PER is higher than that with PER, which leads to a better synergism.

Automated summary

The synergistic fire retardancy of modified melamine resin with pentaerythritol (MF-PER) and ammonium polyphosphate (APP) in polypropylene was studied. MF-PER/APP imparts a fire retardancy mainly by barrier effect and graphitization.