PET foam treated with Directa Plus graphene resists flame penetration seven times longer than neat foam. The tests were carried out by Turin Polytechnic using 120 kg/m3 polyethylene terephthalate foams from BASF, coated with Directa Plus expanded graphene nanoplatelets. The graphene was deposited from water based solutions, using three different dispersants, by manual brush painting onto the foam sample surface (approx. 1.5 – 3.5 % w/w coating/foam). UL94 horizontal and vertical burning tests were carried out using 20 mm thickness foam samples, and flame penetration test using 2 mm thickness samples. The coating interrupted horizontal and vertical burn, increased time to ignition, reduced peak heat release rate by up to 60% and increased time to flame penetration by seven times.
“Directa Plus says new research demonstrates graphene’s flame retardant properties” https://www.proactiveinvestors.co.uk/companies/news/940895/directa-plus-says-new-research-demonstrates-graphene-s-flame-retardant-properties-940895.html
“PET Foams Surface Treated with Graphene Nanoplatelets: Evaluation of Thermal Resistance and Flame Retardancy”, S. Matta et al., Polymers 2021, 13, 501, https://doi.org/10.3390/polym13040501