A new light refractory material

New composites meet stringent fire requirements while lightweighting ships, rail cars and battery boxes for electric cars and planes.

The list of mechanical functions that composite materials are expected to provide is well known and long: Strength, stiffness, toughness, durability, weatherability, corrosion resistance, impact resistance, fire resistance. This last requirement is one that composites have been addressing for many years. However, the industry is seeing an uptick in demand for fire performance, driven by the development of electric vehicles (EVs) — both on the ground and in the air — and increased penetration, finally, into the fire-conscious rail, marine and construction markets.

As will be revealed here, are responding to that market pull, but the industry cannot rely only on traditional fire-resistance solutions to meet the demands of this market. For example, furan and phenolic resins have long been solutions for fire-resistant composites. They are, however, crosslinked via condensation reactions, which makes processing more difficult, often creating porosity that requires multiple operations to achieve a good surface finish. They also tend to be brittle. Meanwhile, fire retardants such as aluminum trihydroxide (ATH), added to resins to provide fire resistance, typically require a loading of 20% by volume, which can adversely affect processing, mechanical properties and surface finish. Meanwhile, halogenated flame retardants, once an attractive alternative, are now banned by pan-European regulations including REACH and RoHS. Thus, the composites industry continues to research and develop new solutions.