Trials suggest that an aluminium phosphonate and melamine cyanurate provide synergistic fire protection coating for ABS. EMPCP (ethylene glycol methyl propionate cylohexanediol phosphonate) was reacted with aluminium isopropoxide to general an aluminium phosphonate (EMPCP-Al). This was tested with polyvinyl formal (PVFO) and melamine cyanurate (MCA), at ratio 88:9:3, as a surface coating for ABS polymer, coating thickness 50 – 130 µm (after 1 – 5 coatings by solvent deposition and evaporation) on 3.5 mm thick ABS samples. Limiting oxygen index (LOI) was increased from 17 (non-coated ABS) to 29 %, and peak heat release rate was reduced by over 50%, achieving UL 94 V-0. Analysis showed that the coating increased carbon dioxide and water release, and decreased hydrocarbon gas release. The authors conclude that this PIN coating achieves fire performance for ABS without modifying mechanical properties.
“Highly efficient intumescent flame retardant coating for ABS: Preparation and application”, J. Chen et al., J Appl Polym Sci. 2022, 139, e51860, https://doi.org/10.1002/app.51860