Effect of nanoclay content on the thermal, mechanical and shape memory properties of epoxy nanocomposites

The bright future of shape memory epoxy polymer (SMEP), to be used in critical industries, can be refined by enhancing its properties and overcoming its limitations. Depicting the great performance of nanofillers in polymer composites, their inclusion in SMEP is expected to emphasize the properties of SMEP. In this study, experimental analyses are conducted to study the effects of nanoclay content on the thermal and mechanical properties of SMEP through dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), X-ray diffraction (XRD), flexural testing and shape memory cyclic testing. The epoxy systems, made of EPON 826 and neopentyl glycol diglycidyl ether (NGDE) and incorporated with 1 wt%, 3 wt% and 5 wt% montmorillonite (MMT) nanoclay, are prepared for characterization. It is found that increasing the nanoclay content decreases the glass transition temperature and increases the thermal stability of SMEP, through DMA and TGA, respectively. The highest values of both the storage modulus at glassy region from DMA and the flexural modulus from the flexural testing are observed for the nanocomposites with 3 wt% nanoclay content. The XRD analysis and TEM micrograph support these results. Meanwhile, only a small difference is observed based on TGA data. Addressing the main use of SMEP, the increment of nanoclay content has improved the shape recovery and shape fixity through the shape memory cyclic testing.