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. This green, facile fabrication offers a promising approach for developing halogen-free flame-retardant ABS.