Henri Vahabi, Université de Lorraine, France, and PolyFlame Newsletter, presented research into fire performance of PIN FR / acrylic resin / fibreglass thermoplastic composites. Today’s aircraft are over 50% by weight composites, enabling weight reduction and so improved fuel efficiency.
Thermoplastics offer both lower weight and faster, cheaper production cycles than thermosets, as well as better recycling potential.
Appropriate combinations of phosphorus FRs (Exolit® OP930 phosphinate and DOPO = 9,10-dihydro-9-oxy-10-phosphaphenanthrene-10-oxide), inorganic FRs (ATH aluminium trihydroxide) and expandable graphite showed peak heat release rate (PHHR) reduced from over 200 to 80 kW/m2, close to the objective performance for aircraft applications of 65 kW/m2.
Henri Vahabi considers that the public needs to be educated both about fire safety and about fire safety chemicals. Flame retardants have a long history of making society safer, for example with the use of alum during the siege of Piraeus in 83 BC or Lussac’s use of APP (ammonium poly phosphate) to address fire risks in Paris theatres in the nineteenth century. These safe PIN FRs continue to be widely used today. The recent bus fire in the French Pyrenees (pinfa Newsletter 57), in which 43 people were killed by fire and smoke, show how fast and deadly fire can be in modern materials. Why are train passengers protected by demanding material fire safety regulations, but not bus and coach users? At the same time, possible health impacts of FRs must be addressed (as underlined by the recent French ANSES report, pinfa Newsletter 57). Tomorrow’s ecological FR solutions will be PIN, with in particular the use of complex phosphorus chemicals such as DOPO, for which toxicology data should be actively developed.