Polymers containing functionalized carbon nanotubes

Abstract

A polymer composite composed of a polymerized mixture of functionalized carbon nanotubes and monomer which chemically reacts with the functionalized nanotubes. The carbon nanotubes are functionalized by reacting with oxidizing or other chemical media through chemical reactions or physical adsorption. The reacted surface carbons of the nanotubes are further functionalized with chemical moieties that react with the surface carbons and selected monomers. The functionalized nanotubes are first dispersed in an appropriate medium such as water, alcohol or a liquefied monomer and then the mixture is polymerized. The polymerization results in polymer chains of increasing weight bound to the surface carbons of the nanotubes. The composite may consists of some polymer chains imbedded in the composite without attachment to the nanotubes. The resulting composite yields superior chemical, physical and electrical properties over polymer composites that are only physically mixed and without binding to the surface carbons of the nanotubes.

We claim:  
     
         1 . A composite comprising a polymerized mixture of functionalized carbon nanotubes and a monomer which can react with said functionalized nanotubes.  
     
     
         2 . A polymer composite comprising a plurality of functionalized carbon nanotubes and polymer chains chemically bound to reactive sites on said nanotubes.  
     
     
         3 . A polymer composite comprising a mixture of functionalized carbon nanotubes with reacted surface carbon atoms, said nanotubes consisting of compositions of 
       [C n H L ]—R m   where C is a surface carbon atom,    n is an integer,    L is a number less than 0.1 n,    m is a number less than 0.5 n,    each of R is the same and is selected from the group consisting of SO 3 H, COOH, NH 2 , OH, R′CHOH, CHO, CN, COCl, halide, COSH, SH, COOR′, SR′, SiR′ 3 , Si(—OR′—) y R′ 3−y , Si(—O—SiR′ 2 )—OR′, R″, Li, AlR′ 2 , Hg—X, TlZ 2  and Mg—X, 
 where y is an integer equal to or less than 3,  
 R′ is hydrogen, alkyl, aryl, cycloalkyl, or aralkyl, cycloaryl, or poly(alkylether),  
 R″ is fluoroalkyl, fluoroaryl, fluorocycloalkyl, fluoroaralkyl or cycloaryl,  
 X is halide, and  
 Z is carboxylate or trifluoroacetate.  
   
     
     
         4 . The polymer composite as recited in  claim 3 , wherein said nanotubes are substantially cylindrical, with a substantially constant diameter and with a length to diameter ratio of greater than five and a diameter of less than 0.5 microns.  
     
     
         5 . The composite as recited in  claim 1  comprising from about 0.25% to about 20% of said nanotubes by weight of said composite.  
     
     
         6 . The composite as recited in  claim 1  comprising from about 1% to about 6% of said nanotubes by weight of said composite.  
     
     
         7 . The composite as recited in  claim 1  comprising from about 3% to about 10% of said nanotube by weight of said composite.  
     
     
         8 . The composite as recited in  claim 1  wherein said polymer composite is substantially solid and free of pores.  
     
     
         9 . The composite of  claim 1  comprising polycarbonates, polyamides, polyesters, polyurethanes or mixtures thereof.  
     
     
         10 . The composite of  claim 9  wherein the polymer comprises organic and/or inorganic hybrids.  
     
     
         11 . A composite polymer comprising a plurality of functionalized carbon nanotubes and polymer chains chemically bound to reactive sites on said nanotubes prepared by 
 a. dispersing functionalized carbon nanotubes in an appropriate vehicle,    b. adding a selected monomer reactive with sites on said functionalized nanotubes to the dispersion; and    c. causing said monomer to polymerize and react with said functionalized nanotubes to form said composite.    
     
     
         12 . A polymer composite as recited in  claim 11  wherein the appropriate vehicle comprises water, alcohol or a liquefied monomer.