Flame retardant performance of carbonaceous nanomaterials on polyester fabric

Flame retardants (FRs) are applied to select consumer products such as baby clothing, construction materials, electronics and furniture upholstery to slow or prevent fire ignition or growth by physical/chemical mechanisms. The most commonly used FRs have historically been halogenated molecules. However, their bioaccumulation in mammals has been investigated, leading to some of them to be banned. As an alternative FR, this study investigated the potential of carbonaceous nanomaterials (CNMs) such as carbon nanotubes (CNTs) and graphene oxide (GO) coating material on polyester fabric. CNMs mass loadings on fabrics were verified by programmed thermal analysis (PTA) and tested for flame retardancy using a new assessment approach based on National Fire Protection Association (NFPA) method 705. Compared with traditional FRs, select CNMs showed similar flame retardancy at lower mass loadings. The oxygen content of CNMs, as measured by X-ray photoelectron spectroscopy (XPS), emerged as a critical parameter with higher oxygen content resulting in reduced flame retardancy of the coating. Non nano-sized carbonaceous materials such a carbon black did not exhibit the same flame retardant properties as CNMs. Multi-walled carbon nanotubes (MWCNTs) and amine functionalized multi-walled carbon nanotubes (e.g., NH₂-MWCNT) required significantly lower mass loadings to achieve flame retardancy similar to traditional FRs and hence are promising alternatives that warrant further investigation.