The invention pertains to a composite material comprising PPTA
(poly-p-phenyleneterephthalamide) and nanotubes having an aspect ratio of
at least 100 and a cross-sectional diameter of 5 nm or less, the
composite material containing up to 12 wt. % of nanotubes, obtainable by
adding the nanotubes to sulfuric acid, decreasing the temperature to
solidify the mixture, adding PPTA to the solid mixture, heating to above
the solidifying point and mixing the mixture, and spinning, casting, or
molding the mixture to the composite material.The process comprises the
steps: a) adding nanotubes having an aspect ratio of at least 100 and a
cross-sectional diameter of 5 nm or less to sulfuric acid at a
temperature above the solidifying point of the sulfuric acid; b)
decreasing the temperature to below the solidifying point of the sulfuric
acid and mixing for a sufficient time to solidify the mixture; c) adding
PPTA to the solid mixture; and d) heating to above the solidifying point
and mixing the mixture.