Characterization and physical properties of aluminium foam-polydimethylsiloxane nanocomposite hybrid structures

This article reports on the fabrication and characterisation of hybrid structures prepared by impregnating an open-cell aluminum foam with polydimethylsiloxane (PDMS) or PDMS reinforced with graphene oxide, GO (PDMS nanocomposite). The effect of the PDMS and the GO on the mechanical, thermal, acoustic absorption and fire retardancy properties of the resulting hybrid structures were evaluated and compared to the individual components (PDMS, PDMS nanocomposite, open-cell aluminium foams). Results demonstrate that the use of the PDMS cured at 65 degrees C, as an void filler of the open-cell aluminium foams, changes mechanical and deformation performance, from a rubbery to brittle behaviour, however attaining a higher level of strength (quasi-static: similar to 5 MPa; dynamic: >15 MPa) in the resulting hybrid structures. This change is due to the low chain mobility of the polymer and effective adhesion with struts of the open-cell aluminium foams. Furthermore, these hybrid structures are extremely sensitive to strain-rate testing, exhibiting a maximum compressive stress increase of more than 300% and 200%, respectively. The presence of the GO within the PDMS improves significantly the non-flammability of the hybrid structures and increases the sound absorption coefficient.