Roger Avakian, Avakian Polychem Consulting, provided a one hour introduction to polymer fire safety, presenting the different principal non-halogenated flame retardant chemistries and how they function to prevent or inhibit fire and summarising key fire performance tests. He introduced the challenges of polymer – flame retardant compositions, including compatibility with processing, fire performance objectives, compatibility with other material performance qualities, durability in application (e.g. weathering), cost (taking into account loading needed) and chemical regulatory constraints (TCSA, REACH, customer chemical specifications …). Tips concerning information sources were provided: use suppliers’ information but also independent sources (science literature, pinfa application brochures) to understand the inherent properties of different FRs (fire mechanism, migration, effect of water); watch videos of fire tests (not just numbers) to understand fire behaviour; consider combining PIN FRs and synergists; initial small scale testing of fire performance but also processing re-processing (recyclability).
Rudolf Pfaendner, Fraunhofer LBF (Institute for Structural Durability and System Reliability) presented non-halogenated FRs which can function in the gas phase (radical generators). This can provide fire inhibition action complementary to char-producing (solid phase) PIN FRs, In particular, he discussed nitrogen and sulphur compounds such as AZO, triazenes, sulfides. He presented developments with oxyimides, which have shown to be effective as PIN FRs alone in some polymers, as synergists with other PIN FRs or can be combined as P or S derivates or metal salts. See Speiss et al. 2021. Oxyimides offer an alternative to ATO (antimony trioxide).