Strong Synergistic\nEffects between Boron-Containing\nCompounds and Aluminum Diethylphosphinate for Enhanced Fire Safety\nand Mechanical Properties of Polyamide 6

Polyamide 6 (PA6) is an eminent engineering plastic renowned\nfor\nits exceptional mechanical attributes, yet its flammability restricts\nits application scope. Aluminum diethylphosphinate (ADP) has exhibited\nan ability to significantly reduce the flammability of PA6, yet it\nis incapable of enhancing the char-forming capacity of PA6. More importantly,\nADP causes serious damage to the mechanical properties of PA6. Here,\na boron-containing polymer (PDBD) was prepared and added to PA6 together\nwith ADP to prepare flame-retardant PA6 composites. Compared with\nPA6/13ADP, the PA6/10ADP/3PDBD sample with 3 wt % PDBD replacing the\nADP not only can pass a UL-94 V-0 rating, but also, the peak of heat\nrelease rate (PHRR) and the total heat release (THR) were reduced\nby 35.6% and 16.5%, respectively. Simultaneously, the incorporation\nof PDBD significantly enhanced the char-forming potential of PA6,\nsignifying a robust synergism between PDBD and ADP in catalyzing and\nfacilitating the char-forming procedure of PA6. Significantly, compared\nto those of PA6/13ADP, the elongation at break and notch impact strengths\nof PA6/10ADP/3PDBD composites are notably increased by 174.3% and\n45.8% due to the robust hydrogen bond between PDBD and PA6. These\nresults illustrate that PDBD can effectively augment the charring\npropensity of PA6/ADP and mitigate the detrimental effects of ADP\non the mechanical properties of PA6. Therefore, this work provides\na simple and feasible method for preparing high-performance PA6 composites.