Synthesis and Properties of a Novel Flame-Retardant Epoxy Resin Containing Biphenylyl/Phenyl Phosphonic Moieties

A novel reactive diol, bis-biphenyloxy (4-hydroxy) phenyl phosphine oxide (BBPHPPO) which contains both biphenylyl and phenyl phosphonic groups was synthesized. Flame retardant advanced epoxy resin was obtained by chain extension of diglycidyl ether of bisphenol-A (DGEBA) with the phosphorus-containing diol (BBPHPPO). The thermal properties and flame retardancy of cured epoxy resin were studied. The resulting BBPHPPO containing epoxy system exhibited higher glass transition temperature than that of advanced epoxy resins prepared from bisphenol-A (BA) and tetrabromobisphenol-A (TBBA). The high char yield and the high LOI value were observed to prove the excellent flame retardancy of this phosphorus-containing epoxy resin.