Solid-state foaming of nano–clay-filled thermoset foams with shape memory properties

A solid-state process was used to produce epoxy foams with different contents of nano-clay (up to 10%wt). The foam properties were studied by means of numerous tests: X-ray analysis, dynamic mechanical analysis, mechanical tests (compression, flexure, indentation, stress relaxation). The straightening effect of the nano-clay filler was investigated and related to the loading conditions and the intrinsic properties of the resin matrix. Small and large foam samples were produced by changing the number of solid precursors during foaming. In the end, shape recovery tests showed that composite foams exhibit remarkably shape memory properties, at least at low filler contents.