TECHNOLOGY FOCUS - POLYMERS - Preferred Composition: The master batch composition comprises preferably at least 50 wt.% graphene. The master batch composition comprises graphene and the polymer in a weight ratio of 1:1-1:10 or 1:1-1:5. The master batch composition comprises a poly(vinylpyrrolidone) that has a number average molecular weight of less than or equal to 10000 u. The graphene/polymer master batch composition comprises greater than 30 (preferably 40) wt.% graphene nanoplatelets. Preferred Components: The graphene is pristine graphene or exfoliated graphene. The polymer is a: poly(vinyl lactam), a polyacrylamide, a thermoplastic polymer (preferred), or a thermoset polymer; or poly(vinylpyrrolidone) (preferred) or poly(N,N-dimethyl acrylamide); or polyethylene, polypropylene, polycarbonate or epoxy. The average thickness of the graphene is less than 10 (preferably less than 3) atomic layers, a minimum of 5% (preferably 20) of the graphene is single atomic layer graphene, and the oxygen content of the graphene is less than 1%, preferably 0.5%. Less than 10% of the graphene nanoplatelets have a maximum diameter of less than 0.5 mu m. The polymer nanocomposite comprises 0.1-50 wt.% graphene. The polymer nanocomposite is produced by melt blending, and the method further comprises extruding the polymer nanocomposite. The solvent is xylenes or methanol. The polymerizable solvent is N-vinyl pyrrolidone or N,N-dimethyl acrylamide. Preferred Method: The mixing is high shear mixing. The slurry of graphene is produced by: treating graphite in an N-alkyl-pyrrolidone to produce solvent exfoliated graphene in the N-alkyl-pyrrolidone; removing most of the N-alkyl-pyrrolidone to produce a concentrated solution or dispersion of graphene in the N-alkyl-pyrrolidone; and adding a solvent to the graphene in N-alkyl-pyrrolidone to produce the slurry of graphene ill the solvent system. The concentrated solution or dispersion of graphene in the N-alkyl-pyrrolidone comprises 2-8% graphene. The master batch composition making method comprises filtration to remove the N-alkyl-pyrrolidone. The solvent system comprises 2-30% N-alkyl-pyrrolidone and 70-98% solvent. In the method of making graphene/poly(vinylpyrrolidone) master batch, the poly(vinylpyrrolidone) is dissolved in the graphene/solvent slurry in a ratio of 1:1-1:5 graphene to poly(vinylpyrrolidone). EXAMPLE - Exfoliated graphene nanoplatelets (200 g) were prepared as a 0.5% solution or dispersion in N-methylpyrrolidone (NMP) from synthetic graphite using solvent exfoliation methods. The 0.5% solution or dispersion was concentrated by micropore filtration until 90% of the solvent had permeated the membrane. Filtration left a 5% slurry of graphene nanoplatelets in NMP as the retentate. An equal volume of dry xylenes was added to the 5% graphene slurry and filtration was continued to reconcentrate the slurry to 5%. The xylenes dilution and reconcentration steps were carried out again to displace NMP with xylenes, resulting in a solvent composition that was approximately 75% xylenes and 25% NMP. Separately, 120 melt polypropylene pellets (200 g) were dissolved in 2 l of xylenes while stirring and heating to boiling. The polypropylene in xylenes solution was then high shear mixed at 8000 rpm. The 5% graphene slurry (4 l) was added to the polymer solution and high shear mixing was continued for a additional 5 minutes. The mixture was allowed to cool overnight with constant agitation, resulting in a viscous suspension. This viscous suspension, was transferred to a rotary evaporator and the solvent was removed by rotary evaporation at 10 mmHg pressure and a temperature of 55 degrees C for xylenes removal and 90 degrees C for NMP removal. Solvent removal left a wet cake containing 50% solids. The wet cake was transferred to aluminum drying pans and dried in a vacuum oven, at 50 mmHg pressure and 100-120 degrees C, to obtain the master batch composition.