Curing agent for polyepoxides and epoxy resins and composites cured therewith

摘要

A curing agent for a polyepoxide has the formula: ##STR1## wherein R. sub.1 is a divalent aryl radical such as phenylene and wherein R.sub.2 is a tetravalent aryl radical such as a tetravalent benzene radical. An epoxide is cured by admixture with the curing agent. The cured epoxy product retains the usual properties of cured epoxides and, in addition, has a high char residue after burning, on the order of 45% by weight. The high char residue is of value in preventing release to the atmosphere of carbon fibers from carbon fiber-epoxy resin composites in the event of burning of the composite.