Rheological properties of poly[ethylene co-(methylacrylate)], polychloroprene and their blends

Rheological properties of blends of poly[ethylene-co-(methylacrylate)] (PEMA, methyl acrylate content 22%) and polychloroprene (CR) have been studied through capillary and dynamic elongational flow. Both capillary and dynamic out of phase viscosity (eta'E) decreases with increased shear rate and frequency in accordance with the power law. On the other hand dynamic extensional viscosity (eta'E) shows a non-linear relationship with frequency with an initial increase followed by a sharp drop at around 11 Hz. The positive activation energy of shear flow indicates lowering of viscosity at higher temperature. 30/70 and 70/30 PEMA/CR blends show maximum relative positive deviation (RPD) in case of shear and dynamic flow respectively. RPD increases linearly with shear rate for capillary flow whereas for dynamic flow, RPD shows non-linear relationship with frequency. The increase of RPD with temperature for both capillary and dynamic flows indicates better interaction between PEMA and CR in their blends. (C) 1998 Elsevier Science Ltd. All rights reserved.