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

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.

Automated summary

This study successfully synthesized a high-efficiency flame retardant HOMP with heterocyclic groups by removing the obstacle of insoluble triazines, and fully characterized its structure, thermal and flame retardant properties. The mechanism and effects on mechanical properties were also investigated. The results showed that HOMP effectively extinguished the combustion of specimens, achieving an LOI value of 29.2% and V0 level in the UL-94 test with only 0.6wt% phosphorus content. However, the addition of HOMP increased the compressibility while significantly decreasing the tensile strength.