A NON-HALOGENATED FLAME RETARDANT ADDITIVEFOR THERMOSET COMPOSITES

摘要

Flame retardants are incorporated into polymeric materials either as additives or reactivernmaterials. Inorganic fillers and halogenated resins are the most common methods used tornachieve flame resistance in fiber reinforced (FRP) composite materials. The flame retardantrnadditives are blended with the resin prior to fiber impregnation at relatively high levels, oftenrnpresenting problems of poor compatibility, leaching, and reduced mechanical properties.rnReactive flame retardants copolymerize with the polymer and do not leach or reduce mechanicalrnproperties. At this time, however, most copolymerized flame retardants are based onrnhalogenated monomers with problems of smoke toxicity. As an alternative, superabsorbentrnpolymers, SAPs, can be loaded with inexpensive inorganic phosphates as the flame retardantrncomponent in composite systems. The resulting SAP flame retardants dramatically improvedrnflame retardancy when blended with common matrix resins (epoxy, unsaturated polyester andrnvinyl ester resins) at relatively low levels. The SAP flame retardant produces no halogen orrnsulfur byproducts on thermal decomposition, generates less smoke than conventionalrnhalogenated polymers, and is amenable to processing in closed molding thermoset resinrnapplications, such as pultrusion.