US Patent 7423084 - High tensile strength polyethylene fibers containing carbon nanotubes

http://www.freepatentsonline.com/7423084.html

This patent from DSM IP Assets B.V. teaches a method for making higher tensile strength nanotube/polymer composites. Claim 1 reads:

1. Method of producing a high strength and high modulus elongated product comprising the steps of :

(a) making a composition comprising a semi-crystalline polymer and nanotubes,

(b) extruding said composition into an elongated product, and

(c) stretching the product below the melting point of the polymer,

wherein in step (a) the composition is a colloidal dispersion of nanotubes in a solution of the polymer.

15. Fibre containing a semi-crystalline polymer and nanotubes, wherein the fibre has a tensile strength of higher than 3.0 GPa, and wherein the semi-crystalline polymer is selected from the group consisting of polyesters, polyketones, polyvinyls and polyolefins.