A generic organometallic approach toward ultra-strong carbon nanotube polymer composites.

Multiwalled carbon nanotubes have been functionalized using n-butyllithium and then covalently bonded to a chlorinated polypropylene. The following addition of the polymer-grafted nanotubes to the chlorinated polypropylene polymer matrix resulted in significant increase of mechanical properties. As nanotube content is increased to 0.6 vol %, Young's Modulus increased by a factor of 3, while both the tensile strength and the toughness increased by factors of 3.8 and 4, respectively. This covalent functionalization enables us to get an efficient dispersion and excellent interfacial stress transfer, potentially leading to new ultra-strong polymer composite materials.