Combustion behavior and thermal degradation properties of epoxy resins with a curing agent containing a caged bicyclic phosphate

A caged bicyclic phosphate structure was combined into epoxy resin to obtain halogen-free flame retardant polymers. LOI, UL-94 test, Cone calorimeter, TG and FTIR techniques were used to characterize the flammability, combustion behavior, thermal degradation properties and char structure. The results show that the incorporation of caged bicyclic phosphate into the epoxy thermosetting structure can greatly improve both the flame retardancy and thermal stability. The toxic gases and smoke generated during combustion are also decreased. The caged bicyclic phosphate 1-oxo-4-hydroxymethyl-2,6,7-trioxa-1-phosphabicyclo [2.2.2] octane (PEPA) acts not only as a curing agent and intumescent flame retardant but also as a smoke inhibitor for epoxy resin. PEPA is a good environmentally friendly flame retardant suitable for many purposes. (C) 2002 Elsevier Science Ltd. All rights reserved.