EFFECTS OF GEOMETRY AND COMPOSITION ON THE VISCOSITY AND THERMOPHYSICAL PROPERTIES OF POLYMER MELTS VIA NONEQUILIBRIUM MOLECULAR DYNAMICS

摘要

Several conclusions can be derived from the results presented in this work. First, we have shown that the zero-shear-rate viscosity of branched chains is remarkably sensitive to the length of the side groups. These side groups, however, do not affect the viscosities at large shear rates. Second, we have shown that binary mixtures of chemically identical polymer molecules of different lengths exhibit a negative excess volume of mixing. Such mixing effects have a non-negligible effect on the rheological properties of polymer blends. Third, our microscopic simulations provide evidence in support, of empirical mixing rules for the viscosity of binary polymer blends.