Study of electroactive shape memory polyurethane-carbon nanotube hybrids

A low temperature electroactive shape-memory material, PU-SWCNT hybrid, was prepared by blending the low molecular weight soft segment polyurethane (PU) with the high conductivity single-walled carbon nanotubes (SWCNTs). The melting points of PU-SWCNT hybrids were changed clearly with the amount of SWCNTs, which were evidently observed by a differential scanning calorimeter (DSC). The influence of the SWCNT contents on the crystal structure of the PU-SWCNTs was detected by X-ray diffraction spectrometer and a hydrogen-bond reconstructed model was proposed in this study. The properties of the PU-SWCNT hybrids are characterized by thermogravimetric analysis (TGA), four-point probe and scanning electron microscopy (SEM). The extent of electroactive shape memory effect for the PU-SWCNT hybrids is strongly affected by the added content of SWCNTs. A good shape recovery of 88% could be obtained using PU-SWCNT hybrids containing 4% SWCNTs. That is, when 30 V was applied to the sample at 5 degrees C, the shape recovery time would only be 90 seconds.