AbstractThe effect of different postcure times on the fracture properties and morphology of an epoxy resin was studied. The fracture energy for crack initiation and arrest was calculated for each sample and plotted as a function of the postcure time. Nodules (25–35 nm in diameter) were observed on all fracture surfaces. Of considerable interest was the alignment of nodules in the direction of crack propagation. Longer postcure times are thought to alter the fracture energy by causing additional crosslinking in the internodular matri
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