Reaction-to-fire parameters of CE/epoxy blend-based CF/FF and BF/FF hybrid composites

The paper investigates and compares the fire reaction of cyanate ester/epoxy polymer blend-based natural/synthetic hybrid composites. Different stacking sequences of carbon or basalt fibres along with flax fabrics were compressed, moulded and subjected to an incident heat flux of 50 kW m−2 for reaction-to-fire parameter's identification using cone calorimetry. Considerable reductions in heat release rate, total heat release and CO2 produced were obtained for cyanate ester/epoxy-based composites compared with an epoxy-based benchmark. On the other hand, the fire growth index improved considerably with the increase in synthetic layers, approx. 70% and 103% for the composite architectures embedding CF reinforcements, 63% and 99% for the BF, respectively. The synthetic fibre content and type did not change significantly time-to-ignition values, but significant differences were recorded at the peak of heat released rate while switching from a resin system to another.