Supramolecular P-Co PIN FR for PC

PIN FR achieves UL 94 V-0 in polycarbonate at 2.5% loading, reduces fire gases, improves mechanical properties. The supramolecular phosphorus-cobalt PIN FR was synthesised by reacting diphenylphosphinic acid (DPPA) with cobalt acetylacetonate. UL 94 V-0 was achieved at 1.5% loading in polycarbonate (thickness not specified, neat PC = V2). At 2.5% PIN FR loading, LOI was improved from 24.5% for neat PC to 33% and peak smoke and carbon monoxide release were reduced by 50-60%. The authors attribute the fire performance to efficient, catalytic char formation and the smoke and toxic gas reduction particularly to the redox effects of cobalt derivatives. The supramolecular P-Co PIN FR shows improvement of processing thermostability, improved impact strength and maintains tensile strength compared to neat PC. A table compares these results to literature data for around twenty other P-based FRs in PC.

“Supramolecular flame retardants towards fire safe polycarbonate with high thermal stability and smoke-suppression properties”, L. Liu et al., Journal of Materials Science & Technology 242 (2026) 173–185 https://doi.org/10.1016/j.jmst.2025.04.016