Synthesis of an efficient phosphorus and triazine ring-containing reactive flame retardant for epoxy resin

Abstract

PurposeIn order to find an appropriate method to synthesize a new high-efficiency flame retardant for epoxy resin.Design/methodology/approachIn this work, a flame retardant with heterocyclic groups, HOMP, was acquired after removing the obstacle from triazines which was not readily soluble. The molecular structure, thermal and flame retardant properties were fully characterized and analyzed. Also, the mechanism was researched through multi-methodologies. As well, the authors evaluated the effects of HOMP on mechanical properties.FindingsThe results suggested that HOMP helped extinguish the combustion of specimens and could reach an LOI value of 29.2% and the V0 level in the UL-94 test with a phosphorus content of only 0.6wt%. With respect to the mechanism, HOMP was a gas-phase flame retardant and helped generate a thicker carbon protective coating. However, for the mechanical properties, the addition of HOMP enhanced the compressibility, while the tensile strength decreased significantly.Originality/valueThe approach not only simplified the operations but also obtained HOMP with excellent flame retardant properties.

New Progress in the Application of Flame-Retardant Modified Epoxy Resins and Fire-Retardant Coatings

“…Furthermore, phosphoric acid and polyphosphoric acid produced by the decomposition of some phosphorus-containing compounds form a melt-adhesive layer that protects the polymer surface and prevents oxygen penetration. The combustion of nitrogen-based flame retardants not only promotes the formation of insulating layers but also releases inert gases to dilute the combustion atmosphere and often co-occurs with phosphorus-based flame retardants [67], which promotes the development of some phosphorus-nitrogen synergistic new flame retardants [37,39]. 9,10-dihydro-9-oxaze-10-phosphoxene-10-oxide (DOPO) and its derivatives have been widely used in EP systems due to their advantages of thermal stability, high flame-retardant efficiency, and strong design ability [13,68,69].…”