Steady shear and linear viscoelastic properties of melt mixed and injection molded samples of polypropylene, polystyrene, and polyethylene nanocomposites with carbon black, vapor grown carbon fibers, and carbon nanotubes

Tailoring the rheological properties of polymers is important for practical applications such as the stabilization of polymer emulsions, blends, and foams. Nanomaterial (i.e. Carbon Nanotubes, Carbon Nanofibers, Dendrimers, and Carbon Black) are an excellent way to modify the mechanical, thermal, electrical, and optical properties of materials. This paper presents steady shear and linear viscoelastic oscillation testing of three polymers: Polyethylene (PE); Polypropylene (PP); and Polystyrene (PS). These polymers were studied in bulk form and as composites containing designated volume fractions of nanomaterials over a range of processing temperatures and conditions. The nanomaterials investigated in this study include Carbon Black, Vapor Grown Carbon Nanofibers, Multiwalled Carbon Nanotubes, Single Walled Carbon Nanotubes, and COOH functionalized Single Walled Carbon Nanotubes. The nanocomposite samples used for rheological experimentation were manufactured by melt mixing and injection molding. We will address whether the melt rheological measurements can unequivocally detect the co-continuous composition range in such systems. We will also investigate the melt flow rate through nanomaterial concentration variations, as well as discuss the storage modulus (G'), viscous modulus (G"), and complex viscosity of homogeneous polymer materials versus carbon nanocomposite material at various frequencies.