A Non-Halogenated Flame Retardant Additive for Pultrusion

A. Small, T. Plaisted, M. Rogers, F. Davis, L. Sterner
Luna Innovations, Advanced Materials Group


Abstract. Flame retardants are incorporated into polymeric materials either as additives or reactive materials. Inorganic fillers and halogenated resins are the most common methods used to achieve flame resistance in fiber reinforced polymer (FRP) composite materials. Inorganic fillers, such as alumina tri-hydrate (ATH), are blended with the resin prior to fiber impregnation at relatively high levels, often presenting problems of poor compatibility, leaching, and reduced mechanical properties. Halogenated monomers, resins, and additives cause problems with smoke toxicity, making them unsuitable for many naval and transportation applications. It has previously been demonstrated that superabsorbent polymers, SAPs, can be loaded with inexpensive inorganic phosphates as the flame retardant component in composite systems. The resulting SAP flame retardants dramatically improved flame exposure when blended with common matrix resins (epoxy, unsaturated polyester and vinyl ester resins) at relatively low levels. The SAP flame retardant produces no halogen or sulfur byproducts on thermal decomposition and generates less smoke than conventional halogenated polymers. The fire, smoke, and mechanical performance of this novel FR material has been characterized on 0.3175 cm - 0.635 cm flat strip pultruded composites and the processability in both polyester and vinyl ester resin systems has been evaluated.

Keywords: Luna flame retardant, ATH, pultursion, flame retardant composites.