Effect of MWCNT content on thermal and shape memory properties of epoxy nanocomposites as material for morphing wing skin

Abstract

In the present study, a shape memory epoxy polymer (SMEP) system was prepared from commercially available EPON 826 and NGDE, and then, 0.5%, 1.0% and 1.5% mass percentage of multi-walled carbon nanotubes (MWCNTs) were incorporated into it so as to prepare nanocomposites. The inclusion of the nanofiller into the SMEP system was expected to enhance its properties. Then, experimental analyses were conducted to study the effect of incorporating different amounts of MWCNTs on the thermal properties of the obtained nanocomposites, namely dynamic mechanical analysis, thermogravimetric analysis (TGA) and shape memory cyclic testing. It was found that the increasing content of MWCNTs in the SMEP system decreased the glass transition temperature of the developed nanocomposites (SMEPCs). TGA results indicated that the incorporation of MWCNTs into the SMEP decreased its thermal stability. The authors explained these results by the lack of interaction between the MWCNTs and the epoxy matrix. In consideration of the use of the SMEP for morphing applications, the increment in MWCNT content was found to improve the shape recovery properties of the SMEP. Thus, the study demonstrates that the incorporation of a MWCNT nanofiller can help enhance the properties of the SMEP system and overcome its limitations, revealing the high potential of the developed shape memory composite materials to be used for various industrial applications.