Carbon nanotube reinforced thermoplastic polymer composites achieved through benzoyl peroxide initiated interfacial bonding to polymer matrices

Abstract

In some embodiments, the present invention is directed to methods of fully integrating CNTs and the surrounding polymer matrix in CNT/polymer composites. In some such embodiments, such integration comprises interfacial covalent bonding between the CNTs and the polymer matrix. In some such embodiments, such interfacial covalent bonding is provided by a free radical reaction initiated during processing. In some such embodiments, such free radical initiation can be provided by benzoyl peroxide. In some or other embodiments, the present invention is directed to CNT/polymer composite systems, wherein the CNTs within such systems are covalently integrated with the polymer. In some or other embodiments, the present invention is directed to articles of manufacture made from such CNT/polymer composite systems.

1 . A CNT/polymer composite system comprising CNTs dispersed in a thermoplastic matrix, wherein the CNTs serve as reinforcement elements, and wherein the CNTs are covalently bonded to the thermoplastic matrix.  
   
   
       2 . The CNT/polymer composite system of  claim 1 , wherein the CNTs are selected from the group consisting of single-wall carbon nanotubes, multi-wall carbon nanotubes, double-wall carbon nanotubes, and combinations thereof.  
   
   
       3 . The CNT/polymer composite system of  claim 1 , wherein the CNTs comprise SWNTs.  
   
   
       4 . The CNT/polymer composite system of  claim 3 , wherein the polymer matrix comprises polypropylene.  
   
   
       5 . The CNT/polymer composite system of  claim 4 , wherein the SWNTs are bonded directly to the polypropylene.  
   
   
       6 . A method comprising the steps of: 
 a) dispersing CNTs, thermoplastic polymer, and a free radical precursor species in a solvent;    b) removing the solvent to form polymer-overcoated CNTs comprising free radical precursor; and    c) compounding the polymer-overcoated CNTs comprising free radical precursor to form a fully-integrated CNT/polymer composite comprising interfacial covalent bonding between the CNTs and the polymer, the polymer serving as a matrix.    
   
   
       7 . The method of  claim 6 , further comprising a step of processing the fully-integrated CNT/polymer composite in an extruder to form a nanotube continuous fiber product.  
   
   
       8 . The method of  claim 7 , wherein the CNTs are substantially aligned in the nanotube continuous fiber product by shear forces associated with extrusion.  
   
   
       9 . The method of  claim 6 , wherein the CNTs are selected from the group consisting of single-wall carbon nanotubes, multi-wall carbon nanotubes, double-wall carbon nanotubes, and combinations thereof.  
   
   
       10 . The method of  claim 6 , wherein the step of dispersing involves the use of a surfactant.  
   
   
       11 . The method of  claim 6 , wherein the solvent is selected from the group consisting of CHCl 3 , THF, toluene, o-dichlorobenzene, and combinations thereof.  
   
   
       12 . The method of  claim 6 , wherein the CNTs comprise SWNTs.  
   
   
       13 . The method of  claim 6 , wherein the thermoplastic polymer comprises polypropylene.  
   
   
       14 . The method of  claim 6 , wherein the free radical precursor species is a peroxide.  
   
   
       15 . The method of  claim 6 , wherein the free radical precursor species is benzoyl peroxide.  
   
   
       16 . A method comprising the steps of: 
 a) dispersing SWNTs, thermoplastic polymer, and an organic peroxide species in a solvent;    b) removing the solvent to form polymer-overcoated SWNTs comprising organic peroxide species;    c) compounding the polymer-overcoated SWNTs comprising organic peroxide species to form a fully-integrated SWNT/polymer composite comprising interfacial covalent bonding between the SWNTs and the polymer, the polymer serving as a matrix; and    d) processing the fully-integrated SWNT/polymer composite in an extruder to form a nanotube continuous fiber product.    
   
   
       17 . The method of  claim 16 , wherein the SWNTs are substantially aligned in the nanotube continuous fiber product by shear forces associated with extrusion.  
   
   
       18 . The method of  claim 16 , wherein the step of dispersing involves the use of a surfactant.  
   
   
       19 . The method of  claim 16 , wherein the solvent is selected from the group consisting of CHCl 3 , THF, toluene, o-dichlorobenzene, and combinations thereof.  
   
   
       20 . The method of  claim 16 , wherein the organic peroxide species is benzoyl peroxide.  
   
   
       21 . The method of  claim 16 , wherein the thermoplastic polymer comprises polypropylene.  
   
   
       22 . An article comprising the CNT/polymer composite system of  claim 1 , wherein the CNTs within the article are substantially aligned.  
   
   
       23 . The article of  claim 22 , wherein the CNTs comprise SWNTs.  
   
   
       24 . The article of  claim 22 , wherein the CNTs within the article are substantially aligned.