METHOD FOR THE PRODUCTION OF A CONDUCTIVE POLYCARBONATE COMPOSITES
The invention relates to a method for the production of an electrically conductive polycarbonate composite on the basis of thermoplastic polycarbonate and carbon nanotubes, wherein acid-functionalized carbon nanotubes are dispersed with molten polycarbonate.
1 - 7 . (canceled)
8 . A process for preparing a conductive carbon nanotube-polycarbonate composite material comprising
(1) treating carbon nanotubes (CNT) with an oxidizing agent to form acid groups on said CNT to obtain an acid-functionalized CNT,
(2) mixing said acid-functionalized CNT with polycarbonate and a transesterification catalyst to obtain a mixture, and
(3) melting and exposing said mixture to shearing forces.
9 . The process of claim 8 , wherein said oxidizing agent is nitric acid, hydrogen peroxide, potassium permanganate, sulfuric acid, or a mixture thereof.
10 . The process of claim 8 , wherein said transesterification catalyst is selected from the group consisting of titanium tetrabutanolate, BF 3 , AlCl 3 , SiCl 4 , PF 5 , Ti 4+ , Cr 3+ , Fe 3+ , Cu 2+ , SiF 4 , and Na + .
11 . The process of claim 8 , wherein said mixing, melting, and exposing to shearing forces of the components in steps (2) and (3) take place in one reaction space.
12 . The process of claim 8 , wherein the exposing to shearing forces in step (3) proceeds at a temperature which is no more than 100° C. above the glass transition temperature of the polycarbonate.
13 . The process of claim 8 , wherein the exposing to shearing forces in step (3) proceeds at a temperature which is no more than 80° C. above the glass transition temperature of the polycarbonate.
14 . A process for producing polycarbonate-coated carbon nanotubes comprising
(A) dissolving the conductive carbon nanotube-polycarbonate composite material obtained from the process of claim 8 in a solvent to obtain a solution,
(B) centrifuging said solution to isolate the polycarbonate-coated carbon nanotubes, and
(C) separating the isolated polycarbonate-coated carbon nanotubes isolated off from the solution.
15 . The process of claim 14 , wherein said solvent is selected from the group consisting of methylene chloride, trichloromethane, monochlorobenzene, dichlorobenzene, N-methylpyrrolidone, and dimethylformamide.
16 . The process of claim 14 , wherein said solvent is dimethylformamide.