Biocompatible hyperbranched polyurethane/multi-walled carbon nanotube composites as shape memory materials

Multi-walled carbon nanotube (MWCNT)-based composites have been prepared by in situ technique using Mesua ferrea L. seed oil-based hyperbranched polyurethane (HBPU) as the matrix. The scanning electron microscope, transmission electron microscope and Fourier transform infrared spectroscopy analyses revealed good dispersion as well as interaction of MWCNT with the matrix. Remarkable recovery of shape to the extent of 98% was obtained after composite formation. More than 300% improvement in tensile strength was observed as compared to the pristine HBPU. Significant enhancement of thermal stability up to 275 degrees C was found even at low MWCNT loading (1 wt.%). Bacterial degradation of the composite films was tested using two strains of Pseudomonas aeruginosa, MTCC 7814 and MTCC 7815. The composites exhibited enhanced biodegradability as compared to the pristine polymer. The cytocompatibility test based on hemolysis of red blood cells showed that the material lacks cytotoxicity. The investigation indicates that the material has high potential as shape memory biomaterial. (C) 2010 Elsevier Ltd. All rights reserved.