PHOSPHORUS-CONTAINING EPOXY FOR FLAME-RETARDANT .1. SYNTHESIS, THERMAL, AND FLAME-RETARDANT PROPERTIES

A new phosphorus-containing oxirane, bis-(3-glycidyloxy) phenylphosphi ne oxide (BGPPO), was synthesized. Further curing BGPPO with diamine c uring agents, dicyanodiamide (DICY), 4,4'-diaminodiphenylmethane (DDM) , and 4,4'-diaminodiphenylsulfone (DDS), respectively, resulted in sev eral phosphorylated epoxy resins. Compared with Epon 828, Eponex 1015, and DER 732, BGPPO showed relatively high reactivity toward diamine a gents via DSC studies. Furthermore, the reactivity of the three curing agents toward BGPPO were found to be in the order of DDM > DICY > DDS . Thermal stability and the weight loss behavior of the cured polymers were studied by TGA. The phosphorylated resins showed lower weight lo ss temperatures and higher char yields than did the Epon 828-based res ins. The high char yields as well as high limited oxygen index (LOI) v alues of the BGPPO-based resins confirmed the effectiveness of phospho rus-containing epoxy resins as flame retardants. (C) 1996 John Wiley & Sons, Inc.