Effect of novel copolyamide charring agents on flame‐retarded polypropylene

Abstract In this article, two novel copolyamide charring agents, ES‐6 and M‐170, were served as charring agents or synergist with ammonium polyphosphate (APP) and dipentaerythritol (DPER) for the flame‐retarded polypropylene (PP). The flame‐retardant system was characterized by limiting oxygen index (LOI), tensile strength, Izod impact strength, thermogravimetric analyses, differential scanning calorimeter (DSC), and scanning electron microscope (SEM). Compared with polyamide 6 (PA6), ES‐6 and M‐170 had better dispersion and compatibility in the PP matrix and enhanced mechanical properties. Meanwhile, as low melting point polyamides, ES‐6 and M‐170 could decrease processing temperature and effectively inhibit side reaction, especially the degradation of APP. In addition, the synergistic effect between ES‐6 and DPER was also investigated. The results showed that the synergistic system containing ES‐6 had better flame retardancy and mechanical performance in comparison with the system only using DPER or the system containing PA6. POLYM. COMPOS., 2013. © 2013 Society of Plastics Engineers