Nano Perspectives
Nonlinear Rheology of Unentangled Polymer Melts Reinforced with High Concentration of Rigid Nanoparticles
Department of Mechanical Engineering, University of Maine, 5711 Boardman Hall, Room 206, Orono, ME, 04469-5711, USA
Nanoscale Research Letters 2010, 5:791-794 doi:10.1007/s11671-010-9557-6
Published: 14 February 2010Abstract
A scaling model is presented to analyze the nonlinear rheology of unentangled polymer
melts filled with high concentration of small spherical particles. Assuming the majority
of chains to be reversibly adsorbed to the surface of the particles, we show that
the emergence of nonlinearity in the viscoelastic response of the composite system
subjected to a 2D shear flow results from stretching of the adsorbed chains and increasing
desorption rate of the adsorbed segments due to the imposed deformation. The steady-state
shear viscosity of the mixture in nonlinear shear thinning regime follows the power
law
where
is the applied shear rate. At large strain amplitude γ 0, the storage and loss moduli in strain sweep tests scale as
and
respectively.
