Cerium molybdate nanosheets as a multifunctional flame retardant for enhancing fire safety and mechanical strength of ABS composites

To mitigate the fire hazard associated with acrylonitrile butadiene styrene (ABS), cerium molybdate (Ce 2 (MoO 4 ) 3 , CM) nanosheets were synthesized via a hydrothermal method and subsequently incorporated into ABS (ABS/CM). The obtained ABS/CM composites exhibited significantly enhanced flame retardancy and smoke suppression. At a 15 wt% CM loading, the peak heat release rate (PHRR) and peak smoke production rate (PSPR) decreased by 39.4 % and 40.5 %, respectively, while the ignition time increased by 26 s compared to pristine ABS. Concurrently, the tensile strength increased by 12.8 %, although the elongation at break decreased by 48.2 %. Thermal stability was also improved, with the residual char yield at 600 °C rising dramatically from 0.89 wt% for pristine ABS to 15.97 wt% for the ABS/CM15. Mechanistic analysis revealed that the CM nanosheets migrate to the composite surface during combustion, forming a protective cerium/molybdenum-rich char layer. This layer acts as an effective heat and oxygen barrier through condensed-phase action. This work demonstrates CM as an efficient halogen-free multifunctional additive for enhancing the fire safety of ABS composites.