Progress in synthesis and application of new phosphorus flame retardants
As polymer materials are widely used in the fields of electrics,construction,pharmaceuticals,food packaging and so on,the research on their flame retardation has attracted the attention of scholars at home and abroad.Organophosphorus-based flame retardants have the advantages of low smoke,non-toxic,low halogen or halogen-free,and they are the future development direction of flame retardants.This paper reviews the research on a series of new phosphorus flame retardants and their flame-retardation properties prepared by reacting three key compounds,namely,phenylphosphonic dichloride,hexachlorocyclotriphosphazene,and 9,10-dihydro-9-oxa-10-phosphaphenanthrene with compounds posscssing active end groups such as hydroxyl and amino groups,and summarizes the problems of phosphorus flame retardants at the present stage.The future research can start from two aspects to improve the scale of industrial production of phosphorus flame retardants.One is to develop new phosphorus flame retardants with better flame-retardation properties and better compatibility;the other is to use the existing phosphorus flame retardants to mix with polymer materials containing polar groups to improve the compatibility of phosphorus flame retardants with polymer materials,thereby improving the flame-retarding properties.