Facile preparation of rapidly electro-active shape memory thermoplastic polyurethane/polylactide blends via phase morphology control and incorporation of conductive fillers

Rapidly electro-active thermoplastic polyurethane (TPU)/polylactide (PLA) shape memory polymer (SMP) blends via phase morphology control and incorporation of conductive multi-walled carbon nanotubes (MWCNTs) were achieved by simple and efficient melt blending in this work. Binary TPU/PLA blends with various composition ratios were firstly prepared, and the effect of phase morphology on shape memory behavior was studied. The optimum shape memory behavior was observed for TPU50/PLA50 blends with co-continuous phase morphology. Then a small number of MWCNTs were selectively incorporated into TPU phase of TPU50/PLA50 and TPU60/PLA40 blends to realize electro-active shape memory effect. The formation of double percolation network imparted TPU/PLA/MWCNT conductive polymer composites with high electrical conductivities in low percolation thresholds, thus realized rapidly electro-active shape memory behaviors. Additionally, the mechanical properties of TPU/PLA blends (50/50, 60/40) can be enhanced by the addition of MWCNTs even at high temperature. Therefore, our work provides a simple way to fabricate polymer blends with rapid electro-active shape memory performances, good mechanical properties as well as good processing capability but low cost.