The Investigation of Intumescent Flame-Retardant Polypropylene Using a New Macromolecular Charring Agent Polyamide 11

This article deals with a new macromolecular charring agent, polyamide 11 (PA11), which is in combination with a small charring agent, pentaerythritol (PER) and a flame retardant, ammonium polyethylene to flame-retardant polypropylene (PP). When compared with polyamide 6 (PA6), an existing macromolecular charring agent extensively reported, PA11 has longer alkyl segment in its chain unit and shows better compatibility with PP; additionally, with a relatively lower melt point close to that of PP, PA11 can be more effectively compounded with PP in the melt state and better dispersed in PP matrix, thus enhancing the flame retardancy and mechanical properties. Moreover, with certain synergistic effects between PA11 and PER, the system using PA11/PER as composite charring agents showed better charring performance in comparison with the system only using PER. POLYM. COMPOS., 30:221-225, 2009. (C) 2008 Society of Plastics Engineers