A Phosphorus-Bromine Flame Retardant for Engineering Thermoplastics—A Review

A brominated phosphate was evaluated as a flame retardant in a polycarbonate and various polycarbonate blends. This flame retardant was found to be significantly more effective than an all-bromine and an all- phosphorus flame retardant, and bromine-phosphorus synergy was demon strated. The synergy is more pronounced when both the bromine and phosphorus are in the same molecule. The brominated phosphate is melt blendable and acts as a processing aid increasing extrusion output, lowering injection molding temperature and reducing energy consumption. The polymers investigated were polycarbonate, polycarbonate/ABS blend and poly carbonate/PET blend, as well as modified polyphenylene oxide.