Preparation and characterization of electro-active shape memory PCL/SEBS-g-MA/MWCNT nanocomposites

In this work, novel thermally responsive shape memory polymer (SMP) blends of poly(caprolactone) (PCL) and maleic anhydride grafted polystyrene-block-poly(ethylene-co-butylene)-block-polystyrene (SEBS-g-MA) blends and electro-active PCL/SEBS-g-MA/multi walled carbon nanotube (MWCNT) nanocomposites with different compositions were prepared by melt blending technique. The effects of the PCL content (30-40-50%) on morphological, thermal, mechanical and shape memory properties were investigated. Based on SEM analysis, co-continuous morphology was observed in the blend having the weight ratio of 50:50 (50 PCL-SOMA). The thermally triggered shape memory properties which were characterized by a dynamic mechanical analyzer (DMA) showed that the 50 PCL-50MA exhibited the highest fixing (R-f 98.28%) and recovery ratios (R-r 87.97%) among the SMP blends. In the second part of the study, the 50 PCL-SOMA blend nanocomposites were produced with different amounts of multiwalled carbon nanotubes (MWCNTs) and their thermal, mechanical, morphological, electrical and electro-active shape memory properties were investigated. The blend nanocomposite including 10 phr CNT indicated the lowest volume resistivity value (3.82 Omega cm). The same nanocomposite also showed elecmactive shape memory property generating Joule heat under 40 V voltage with the shortest recovery time (56 s). The nanocomposite also exhibited sensor behaviour when it was subjected to finger bending deformation.