A REVIEW OF PHOSPHORUS-CONTAINING FLAME RETARDANTS

The flame retardant mechanism described for phosphorus-containing flame retardants includes both a condensed and a vapor phase mechanism depending on the type of phosphorus compound and the polymer. Intumescence is also described. Chemical structures of the flame retardant are shown. Specific applications for red phosphorus, organophosphates, chlorophosphates and bromophosphates are described. The use of triarylphosphates in PVC, modified polyphenylene oxide, and polycarbonate/ABS is described. The chlorophosphates are used in polyurethanes and the bromophosphates in engineering thermoplastics. Flammability and mechanical properties are given for specific polymers.