Synergistic effect of halloysite nanotubes on flame resistance of intumescent flame retardant poly(butylene succinate) composites

Abstract

A novel intumescent flame retardant poly(butylene succinate) (IFR‐PBS) with antidripping property was prepared using halloysite nanotubes (HNTs) as the synergistic agent. Ammonium polyphosphate (APP), melamine (MA), pentaerythritol (PER), and halloysite nanotubes (HNTs) were added in PBS via melt blending. The effects of HNTs as the synergistic agent on the flame retardancy property, thermal property, and mechanical property of IFR‐PBS composites were investigated. Cone calorimetry revealed that partial substitution of IFR by HNTs (1.5 wt%) substantially improved the flame retardancy of IFR‐PBS with a reduction of heat release rate (HRR), total heat release (THR), and total smoke production (TSP). In addition, the limiting oxygen index value was increased from 42.1 to 58.2 with only 1.5 wt% addition of HNTs. The incorporation of HNTs also enhanced the thermal stability of the IFR‐PBS composites and reinforced the composites. Scanning electron microscopy (SEM) results showed that the composite containing HNTs had a tighter protective char layer after cone calorimeter test, which protected the underlying polymer from the external heating. Overall, the results indicated that suitable amounts of HNTs had a noticeable synergistic effect on the flame retardancy property of IFR‐PBS composites. POLYM. COMPOS., 40:202–209, 2019. © 2017 Society of Plastics Engineers