The Investigation of Melamine Polyphosphate Flame Retardant Polyamide-6/Inorganic Siliciferous Filler with Different Geometrical Form

Melamine polyphosphate (MpolyP) was used to flame retard polyamide-6 filled with siliciferous fillers including fibrous wollastonite, laminar talc, and spherical glass bead. The mechanical performance, flame retardancy of these flame retarded materials, and the influence of these fillers on charring behavior were investigated. The results show that wollastonite/MpolyP/PA6 system has the best mechanical properties as compared with talc/MpolyP/PA6 and glass bead/MpolyP/PA6 system due to good reinforcing effects of the fibrous filler in resin matrix. Otherwise, the char morphology observation shows that spherical glass beads separates from the char matrix during the expansion of the char layer, which hardly improves the char quality. However, fibrous wollastonite and laminar talc can well combine with the char layer, thus enhancing the flame retardancy as a part of the charred layer. It is proved that the laminar talc favors the formation of more condensed char because of its barrier effects, and the fibrous wollastonite with quite high aspect ratio can effectively reinforce both the resin and the charred layer, which leads to the remarkable improvement of the flame retardancy. Consequently, polyamide-6/Mpolyp/wollastonite system shows the best flame retardancy among the above systems. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 113: 2046-2051, 2009