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

Abstract

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-50MA). 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 (Rf 98.28%) and recovery ratios (Rr 87.97%) among the SMP blends. In the second part of the study, the 50 PCL-50MA 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 Ω cm). The same nanocomposite also showed elecro-active 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.