A new intumescent flame-retardant: preparation, surface modification, and its application in polypropylene

Melamine salt of tripentaerythriol phosphate (MTP), as a new intumescent flame-retardant, was prepared from tripentaerythritol (TPE), polyphosphoric acid, phosphoric pentoxide, and melamine, and then incorporated into polypropylene (PP) to obtain flame-retarded PP-MTP. FT-IR analysis showed that MTP was in the form of cage structure. The flammability, combustion behavior, and thermal degradation and stability of flame-retarded PP were characterized by using LOI, UL-94 test, cone calorimetry, and TGA, respectively. By SEM, the char structure of PP-MTP was analyzed. XRD diffraction tests showed that PP-matrix of PP-MTP presented better crystallized phases, when MTP was modified by methyl hydrogen siloxane. The relations of the dispersion of MTP in PP matrix to the compatibility between PP and MTP, and to the flame retardancy were discussed. Copyright (C) 2008 John Wiley & Sons, Ltd.