Synergistic and Catalytic Effects in Flame Retardancy of Polymeric Materials— An Overview

Abstract

Synergistic and antagonistic effects of two or more additives are often encountered in flame retardancy of polymeric materials. Halo gen-antimony synergism is the best known. Evidence for bromine-ammonium, bromine-chlorine and bromine-phosphorus synergisms has been observed in some systems. Useful phosphorus-nitrogen synergism has frequently been ob served and has been studied in detail, with the result that various postulates can explain the effect. Combinations of phosphorus compounds are sometimes syner gistic and various combinations of phosphorus with intumescent char-forming agents are often highly efficacious as flame retardants.