Posted on 07/03/2022 in Fire Safety 2022
Comparing PIN and halogenated FRs in PP

A novel PIN FR achieved fire and mechanical performance comparable to a brominated/antimony FR package. In polypropylene, a novel mono-constituent, intumescent PIN FR (PNP1D, combining phosphate ester, polyhydroxyl and melamine) was compared to DecaBDE or DecaBDE+HBCD (Br-FRs) with ATO (antimony trioxide). The BrFR systems could achieve UL 94 V-0 (thickness not specified, “standard strip”) at 30% Br-FR loading, and fire performance was improved with addition of an anti-drip agent (in this case nano-sheet kaolin (SK-80) at 6% loading). The PIN FR (PNP1D) achieved UL 94 V-0 at 23% loading. PNP1D did not significantly modify the polypropylene tensile strength at this loading, but reduced impact strength from 43.1 kJ/cm2 (pure PP) to c. 11, similar to the 10 – 12 for the Br-FR systems which passed UL 94 V-0. Processing would also be impacted by the FRs: with maximum and balancing torques (Nm) for pure PP of 29 and 3 compared to 33 and 5 with PNP1D or 31 – 44 and 4.3 – 6 for the Br-FR packages (without or with SK-80).

“Flame Retardant Properties and Mechanical Properties of Polypropylene with Halogen and Halogen-Free Flame Retardant System”, X. Zhu et al., Journal of Physics: Conference Series 2160 (2022) 012031,

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