Recent advances in application of phosphazenes for flame retardant polymer materials

Phosphazenes are a new family of organic-inorganic compounds contained alternating phosphorus and nitrogen in their skeleton and organic groups in their branched chain.It has been used in various fields, such as fire retardant, biomedical, materials polymer conductor, liquid crystal, fuel and catalyst on account of its special structure and excellent performance.Phosphazenes are provided with superior flame retardant properties due to its high content of elements phosphorus and nitrogen.In recent years, cyclotriphosphazenes flame retardants has been widely used in polymer materials.This paper reviews the synthesis and application of cyclotriphosphazenes flame retardants with diverse substitutional groups in the last decade, emphatically introduces their impact on the flame retardantcy and thermal stability of different polymer materials such as epoxy resin, ABS, polyolefin and polyester.Furthermore, the influence rule and flame retardant mechanism are summarized, and the trend of its application is also prospected.