Synthesis and Characterization of a New Copolymer Consisting of Polyamide 1210 and Reactive Phosphorus−Nitrogen Flame‐Retardant

Abstract The thermal stability and reactivity of organophosphorus flame‐retardants play a critical role in synthesizing copolymerized flame‐retardant polyamides. Herein, this work successfully synthesizes a flame‐retardant CEPPA‐DDA salt (CDS) with both good thermal stability and high reactivity by reacting 2‐carboxyethyl phenyl phosphonic acid (CEPPA) with 1,12‐dodecanediamine (DDA). Flame‐retardant polyamide 1210 (FRPA) is further prepared by copolymerizing the CDS, DDA, and sebacic acid (SEA). The test results show that the introduction of CDS can significantly improve the flame‐retardant properties of FRPA. Specifically, the flame‐retardant polyamide 1210 (FRPA‐7) with 7 wt% CDS addition can reach V‐0 grade according to UL‐94 standard, accompanying limiting oxygen index value of 30.2% and tensile strength of 38.62 MPa. Compared with pure polyamide 1210, the peak heat release rate and total heat release rate of FRPA‐7 reduce by 24.11% and 9.40%, respectively. This study provides a simple strategy to prepare flame‐retardant polyamides with high flame retardancy and good mechanical properties, which are expected to show great potentials in future industrial applications.