Carbon nanotube-reinforced nanocomposites

Abstract

Carbon nanotubes (CNTs) are so long that they cannot be penetrated inbetween carbon fibers during a prepreg preparation process, and are shortened in order for them not to be filtered out by the carbon fibers. This results in a huge improvement of the mechanical properties (flexural strength and flexural modulus) compared with neat epoxy.

1 .- 7 . (canceled) 
     
     
         8 . A method for making a composite material, comprising:
 shortening carbon nanotubes to an average length of less than 2 μm;   dispersing the shortened carbon nanotubes in a solution;   mixing the solution of shortened carbon nanotubes with a polymer to produce a carbon nanotube reinforced polymer; and   combining the carbon nanotube reinforced polymer with carbon fibers in a manner so that the shortened carbon nanotubes are impregnated in between individual ones of the carbon fibers to produce the composite material.   
     
     
         9 . The method as recited in  claim 8 , further comprising curing the composite material. 
     
     
         10 . The method as recited in  claim 9 , wherein the cured composite material has a flexural strength greater than that of a cured carbon fiber reinforced polymer not combined with carbon nanotubes. 
     
     
         11 . The method as recited in  claim 9 , wherein the cured composite material has a flexural modulus greater than that of a cured carbon fiber reinforced polymer not combined with carbon nanotubes. 
     
     
         12 . The method as recited in  claim 9 , wherein the cured composite material has a flexural strength greater than that of a cured carbon fiber reinforced polymer combined with carbon nanotubes with an average length greater than 2 μm. 
     
     
         13 . The method as recited in  claim 9 , wherein the cured composite material has a flexural modulus greater than that of a cured carbon fiber reinforced polymer combined with carbon nanotubes with an average length greater than 2 μm. 
     
     
         14 . The method as recited in  claim 8 , wherein the combining does not filter out the shortened carbon nanotubes to ends of the carbon fibers. 
     
     
         15 . The method as recited in  claim 8 , wherein an average length of the carbon nanotubes is less than 2 μm. 
     
     
         16 . The method as recited in  claim 8 , wherein the polymer is thermosetting or thermal plastics. 
     
     
         17 . The method as recited in  claim 16 , wherein the thermosetting plastics are selected from the group consisting of polyimide, phenolics, cyanate easters, and bismalemiides. 
     
     
         18 . The method as recited in  claim 8 , wherein the carbon nanotubes are not functionalized. 
     
     
         19 . The method as recited in  claim 8 , wherein the carbon nanotubes are functionalized to carboxylic functional groups or amine functional groups. 
     
     
         20 . The method as recited in  claim 8 , wherein the carbon nanotubes are functionalized to amine functional groups. 
     
     
         21 . The method as recited in  claim 8 , wherein the carbon fibers are unidirectional carbon fibers.