Hexachlorocyclotriphosphazene is used as a raw material for the preparation of cyclotriphosphazene derivatives and phosphazene flame retardant materials. Its traditional synthesis method has the disadvantages of long reaction time and low synthesis yield. Researchers have carried out optimization exploration on the selection of reaction raw materials, catalyst selection, separation and purification and other process conditions, and achieved good results, providing technical guarantee for the development of upstream raw materials for the development of phosphazene flame retardant materials industry.

At present, the preparation cost of cyclotriphosphazene flame retardant is still generally high, and the synthesis process is relatively complicated. It will take some time for it to enter industrial production and application. Therefore, the development of low-cost cyclotriphosphazene flame retardant and the optimization of synthesis process have become urgent problems to be solved in the cyclotriphosphazene flame retardant industry.

In order to improve the flame retardant properties, cyclotriphosphazene derivatives with multi-functional network structures and phosphazene organic-inorganic nanocomposite phosphazene flame retardant materials have become new research directions.

Additive cyclotriphosphazene derivatives should develop macromolecular structures that have good compatibility with the resin matrix and are not easy to migrate and precipitate.

While improving the flame retardancy of composite materials, cyclotriphosphazene derivatives also have certain effects on the mechanical properties, electrical properties and heat resistance of composite materials. These effects are both positive and negative. Therefore, in the future, when designing and developing cyclotriphosphazene derivatives, attention should also be paid to the application of the derivatives in the heat resistance, electrical properties and mechanical properties of phosphazene flame retardant materials.

The introduction of new elements such as silicon not only improves the flame retardant efficiency of phosphazene derivatives, but also is green and environmentally friendly; however, the substitution reaction process is complicated, and due to factors such as steric hindrance, some chlorine atoms may not be completely replaced by silicon atoms. Therefore, new process routes need to be studied to achieve the complete replacement of chlorine atoms on cyclotriphosphazene by synergistic flame retardant elements, so as to obtain more environmentally friendly and efficient phosphazene flame retardant materials.