formers illustratively polyol spumifics amine blowing agents and phosphate acid producers the composition for use in the following tests was a two component epoxy based thermally activated coating which when exposed to flame or thermal extreme volatilizes at fixed temperatures exhibiting a small volume increase greater than twice the original thickness through the formation of an open cell matrix and absorbs and blocks heat to protect the substrate material the composition included a polyfunctional alcohol a 1 3 5 triazine 2 4 6 triamine an epoxy resin and a polymer of bis ethylene oxy methane containing disulfide linkages and curable terminal thiol groups a polysulfide the exemplary composition is a two component modified epoxy having a nominal formula as follows a graphite fabric was pressed into the lower layer before it set the lower layer was allowed to cure for 17 hours and 3 mm of the upper layer composition of example 1 was sprayed over the lower layer the composite was allowed to cure at 30 u00b0 c for one month the test article prepared in accordance with example 2 was exposed to a jet fire in accordance with the procedure set out in oti 95634 dated 1996 the test showed that the composite structure provided approximately sixty minutes of protection under the conditions of the test smaller scale tests indicate that the composite system provides far greater protection than the protection given by a thickness of either the upper layer or the lower layer alone.