Improved compositions comprise a
polymer and
carbon fibers, such as nanotubes. In some embodiments, the
carbon fibers, e.g., nanotubes, can be mechanically blended or incorporated into the
polymer, while in some embodiments carbon nanotubes also may be covalently bonded to the
polymer to form corresponding covalent materials. In particular, the polymer can be covalently bonded to the side walls of the carbon nanotubes to form a composite with particularly desirable mechanical properties. Specifically, the bonding of the polymer to the
nanotube sidewall can provide desirable mechanical properties of the composite due to the orientation relative to other types of association between the nanotubes and the polymer. The
processing of the nanotubes can be facilitated by the dispersion of the nanotubes in an
aqueous solution comprising a hydrophylic polymer, such as
ethyl vinyl acetate. A dispersion of nanotubes can be combined with a polymer in an
extrusion process to blend the materials under high shear, such as in an extruder. In general, various articles can be formed that take
advantage of the properties of the composite materials incorporating a polymer and
carbon fibers, such as carbon nanotubes.