Green facile fabrication of halogen-free flame-retardant ABS with high mechanical performance

The development of halogen-free flame-retardant acrylonitrile-butadiene-styrene (ABS) with both high fire safety and excellent mechanical properties remains a significant challenge. Herein, cerium chemical hybrid ammonium polyphosphate (Ce@APP) was synthesized through an ion-exchange reaction in a water-ethanol solvent, and halogen-free intumescent flame-retardant ABS composites (denoted as ABS6) were fabricated by incorporating a phosphamide derivative (DP). Different from the APP/DP system, the excellent synergistic effects of Ce@APP/DP, including strong catalytic cross-linking carbonization, gaseous dilution and capture mechanism at high temperatures (especially above 570 °C), endowed the ABS composites with excellent fire safety. ABS6 achieved a limited oxygen index (LOI) of 28.6% and satisfied the UL-94 V0 rating. Furthermore, compared with those of pristine ABS, the peak heat release rate (pHRR) and peak smoke production rate (pSPR) of ABS6 were reduced by 76.6% and 65.9%, respectively. Notably, the good interfacial compatibility between the Ce@APP/DP system and the ABS matrix mitigated the deterioration of mechanical properties. The tensile and flexural strengths of ABS6 remained nearly the same, while its impact strength remained at 4.02 kJ m^-2. This green, facile fabrication offers a promising approach for developing halogen-free flame-retardant ABS.