Poly(ethylene terephthalate)-graphene nanocomposites from improved dispersion

Abstract

A composition and a method are provided for graphene reinforced polyethylene terephthalate (PET). Graphene nanoplatelets comprising a suitable surface area are added to a dispersion medium for producing graphene reinforced PET. The average surface area may range between substantially 15 m 2 /g and 750 m 2 /g. In some embodiments, the dispersion medium may be comprised of ethylene glycol. The dispersion medium and graphene nanoplatelets are sonicated to disperse the nanoplatelets within the dispersion medium. The dispersion medium and graphene nanoplatelets are centrifuged to remove larger nanoplatelets that are not suitably dispersed within the dispersion medium. A supernatant solution of dispersed graphene nanoplatelets and dispersion medium is decanted and then used for polymerization of the graphene reinforced PET. The resultant graphene reinforced PET is comprised of a continuous matrix of PET with a reinforcement material comprising dispersed phase graphene nanoplatelets.

What is claimed is: 
     
         1 . A polymer nanocomposite comprising:
 a matrix comprising polyethylene terephthalate; and   a reinforcement material comprising dispersed phase graphene nanoplatelets.   
     
     
         2 . The nanocomposite of  claim 1 , wherein the graphene nanoplatelets comprise a surface area of at least about 15 m 2 /g. 
     
     
         3 . The nanocomposite of  claim 1 , wherein the graphene nanoplatelets comprise an average thickness ranging between about 10 nanometers (nm) and 20 nm. 
     
     
         4 . The nanocomposite of  claim 1 , wherein the graphene nanoplatelets comprise a surface area ranging between about 120 m 2 /g and 150 m 2 /g. 
     
     
         5 . The nanocomposite of  claim 1 , wherein the graphene nanoplatelets comprise an average thickness ranging between about 6 nm and 8 nm. 
     
     
         6 . The nanocomposite of  claim 1 , wherein the graphene nanoplatelets comprise a surface area ranging between about 300 m 2 /g and 750 m 2 /g. 
     
     
         7 . The nanocomposite of  claim 1 , wherein the graphene nanoplatelets comprise an average thickness ranging between about 2 nm and 3 nm. 
     
     
         8 . A method for preparing graphene reinforced polyethylene terephthalate (PET), comprising:
 obtaining graphene nanoplatelets comprising a suitable surface area;   adding the graphene nanoplatelets to a dispersion medium suitable for producing PET;   sonicating the dispersion medium and graphene nanoplatelets so as to cause a homogeneous dispersion of the graphene nanoplatelets within the dispersion medium;   centrifuging the dispersion medium and graphene nanoplatelets to remove a portion of larger graphene nanoplatelets that are not suitably dispersed within the dispersion medium;   decanting a supernatant solution of graphene nanoplatelets dispersed in the dispersion medium; and   using the supernatant solution for polymerization of the graphene reinforced PET.   
     
     
         9 . The method of  claim 8 , wherein the graphene nanoplatelets comprise a surface area of at least about 15 m 2 /g. 
     
     
         10 . The method of  claim 8 , wherein the graphene nanoplatelets comprise a surface area ranging between about 120 m 2 /g and 150 m 2 /g. 
     
     
         11 . The method of  claim 8 , wherein the graphene nanoplatelets comprise a surface area ranging between about 300 m 2 /g and 750 m 2 /g. 
     
     
         12 . The method of  claim 8 , wherein sonicating comprises immersing the solvent and graphene nanoplatelets in a bath sonicator for a period of time and operating the bath sonicator at a frequency suitable for dispersing the graphene nanoplatelets within the solvent. 
     
     
         13 . The method of  claim 12 , wherein sonicating comprises selecting the period of time so as desirably reduce an average length and width of the graphene nanoplatelets. 
     
     
         14 . The method of  claim 12 , wherein the frequency is a ultrasonic and the period of time ranges between at least 30 minutes and 180 minutes. 
     
     
         15 . The method of  claim 8 , wherein centrifuging comprises subjecting the solvent and graphene nanoplatelets to a rotational speed of centrifugation ranging between at least 1400 RPM and 7200 RPM. 
     
     
         16 . The method of  claim 8 , wherein adding further comprises selecting polyethylene glycol as the dispersion medium suitable for producing the graphene reinforced PET. 
     
     
         17 . The method of  claim 16 , wherein selecting polyethylene glycol comprises selecting any one of PEG-300, PEG-400, and PEG-600 as the dispersion medium. 
     
     
         18 . The method of  claim 8 , wherein adding further comprises selecting ethylene glycol as the dispersion medium suitable for producing the graphene reinforced PET. 
     
     
         19 . The method of  claim 18 , wherein using the supernatant solution for polymerization further comprises performing an esterification reaction to produce bis(2-hydroxyl ethyl) terephthalate (BHET) with water as a by-product, followed by performing a polycondensation reaction so as to produce the graphene reinforced PET. 
     
     
         20 . The method of  claim 19 , wherein performing the polycondensation reaction further comprises including one or more catalysts comprising any one or more of Antimony (Sb), Cobalt (Co), and Phosphoric Acid.