Engineering Sb2MoO6-decorated C3N4 nanoflakes for improving flame retardancy, smoke suppression and mechanical strength of acrylonitrile-butadiene-styrene

Engineering Sb2MoO6-decorated C3N4 nanoflakes for improving flame retardancy, smoke suppression and mechanical strength of acrylonitrile-butadiene-styrene

To address the trade-off between flame retardancy and mechanical strength of acrylonitrile butadiene-styrene (ABS), the Sb2MoO6-modified graphitic carbon nitride (CN-AM) nanoflakes with different mass ratios of Sb2MoO6 (AM) to graphitic carbon nitride (g-C3N4) were successfully prepared in this work. When the mass ratio of g-C3N4 to AM is 100:10, the resultant CN-AM1 nanosheets can be evenly distributed within ABS at different addition amounts. Due to the physical barrier effect of the well-dispersed CN-AM1, the ABS/(CN-AM1) composites show well-maintained initial decomposition temperatures (368–375 °C) and increased char residues (up to 2.72 wt% at 700 °C) relative to pure ABS. The addition of CN-AM1 also brings about the enhanced tensile strength due to its rigid nanosheet structure, and the tensile strength of ABS/(CN-AM1)15 with 15 wt% of CN-AM1 reaches 76.4 MPa, which is increased by 18.8 % compared with ABS. During combustion, the degradation products of CN-AM1 can function in the condensed phase to suppress the heat release and smoke generation, as confirmed by 62.5 % and 49.7 % reductions in peak heat release rate (PHRR) and peak smoke production rate (PSPR) of ABS/(CN-AM1)15 relative to ABS. The limiting oxygen index (LOI) and vertical combustion (UL-94) classification of ABS/(CN-AM1)15 are up to 28.9 % and V-0, demonstrating satisfactory flame retardancy. Thus, this work delivers an effective design strategy for enhancing flame retardancy, thermal stability and mechanical strength of ABS by well-designed nanoflakes.