Synthesis and Application of Arylaminophosphazene as a Flame Retardant and Catalyst for the Polymerization of Benzoxazines

Abstract

A novel type of phosphazene containing additive that act both as catalyst and as flame retardant for benzoxazine binders is presented in this study. The synthesis of a derivative of hexachlorocyclotriphosphazene (HCP) and meta-toluidine was carried out in the medium of the latter, which made it possible to achieve complete substitution of chlorine atoms in the initial HCP. Thermal and flammability characteristics of modified compositions are revealed. The modifier catalyzes the process of curing and shifts the beginning of reaction from 222.0 C for pure benzoxazine to 205.9 C for composition with 10 phr of modifier. The additive decreases the glass transition temperature of compositions. Achievement of the highest category of flame resistance (V-0 in accordance with UL-94) is ensured both by increasing the content of phenyl residues in the composition and by the synergistic effect of phosphorus and nitrogen. Brief research of the curing kinetics disclosed the complex nature of the reaction. An accurate two-step model is obtained using extended Prout-Tompkins equation for both steps.

Two high toughness and flame retardant DOPO-containing polybenzoxazines based on polyether-urea

“…24 Variability in the molecular design of phosphazenes allows one to use them as a base of new flame retardants for benzoxazines. 25 In order to improve the inflame retarding property, the syntheses of DOPO containing benzoxazines were reported. [26][27][28] Together with the structure modification by designing new benzoxazine monomers, there are other approaches for improving the performance of PBzs.…”

A study on the flame retardant modification of bisphenol A benzoxazine

“…As is known to all, phosphorus‐nitrogen flame retardant, as an efficient and environmentally friendly new flame retardant, 26,27 has a broad application prospect, 28,29 and will replace the toxic traditional halogen flame retardant in the future 30 . With more and more research and exploration of phosphorus‐nitrogen flame retardants, many new phosphorus‐nitrogen flame retardants have been developed and used in various thermoplastics or thermosetting plastics to meet their flame retardant properties and thermal properties 31–33 …”