Synthesis and characterization of CNT/thermoplastic polyurethane composites with a high- toughness

Carbon nanotubes( CNTs) were grafted with acrylic acid-3-( perfluoro-3-methykbutyl)-2-hydroxypropylate by an oxygen plasma-assisted method to increase their dispersion in thermoplastic polyurethane( TPU). The TPU monomers and the grafted CNTs were mixed and polymerized to prepare the CNT / TPU composites. Results showthat the grafting procedure has little effect on the structure of the CNTs. The grafted CNTs have a fluorine content of 10. 40% and a diameter of about 30 nm,and are uniformly dispersed in the TPU matrix. The tensile strength and elongation at fracture of the composites have maxima of 36. 5 MPa and 630%,respectively,at a CNT content of 0. 3%,and these are respectively 40. 4% and 26. 5% higher than those of pure TPU. Moreover,the surface free energy of the composites decreases from 27. 3 to 9. 9 m N / m with increasing CNT content from 0 to 0. 8%.