A NON-HALOGENATED FLAME RETARDANT ADDITIVE FOR THERMOSET COMPOSITES

摘要

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 (FRP) composite materials. The flame retardant additives are blended with the resin prior to fiber impregnation at relatively high levels, often presenting problems of poor compatibility, leaching, and reduced mechanical properties. Reactive flame retardants copolymerize with the polymer and do not leach or reduce mechanical properties. At this time, however, most copolymerized flame retardants are based on halogenated monomers with problems of smoke toxicity. As an alternative, 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 retardancy 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, generates less smoke than conventional halogenated polymers, and is amenable to processing in closed molding thermoset resin applications, such as pultrusion.