Polyamide 6 with a flame retardant encapsulated by polyamide 66: Flame retardation, thermo-decomposition and the potential mechanism

A novel encapsulated flame retardant containing phosphorus-nitrogen (MSMM-Al-P) was prepared by encapsulating with polyamide 66 (PA66-MSMM-Al-P) for the flame retardation of polyamide 6 (PA6). The structure and thermal properties of PA66-MSMM-Al-P were characterized by Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy and thermogravimetric analysis. The flammability of PA6 containing flame retardants (MSMMAl-P and PA66-MSMM-Al-P) was investigated by the limiting oxygen index test, vertical burning test and cone calorimeter. The flame retardancy and cone calorimetric analyses suggested a synergistic effect between PA66 and MSMM-Al-P in the flame-retardant PA6. Thermal stability of the flame-retardant PA6 was also investigated.