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 bee n studied through capillary and dynamic elongational flow. Both capill ary and dynamic out of phase viscosity (eta'E) decreases with increase d shear rate and frequency in accordance with the power law. On the ot her hand dynamic extensional viscosity (eta'E) shows a non-linear rela tionship with frequency with an initial increase followed by a sharp d rop at around 11 Hz. The positive activation energy of shear flow indi cates lowering of viscosity at higher temperature. 30/70 and 70/30 PEM A/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-linea r relationship with frequency. The increase of RPD with temperature fo r both capillary and dynamic flows indicates better interaction betwee n PEMA and CR in their blends. (C) 1998 Elsevier Science Ltd. All righ ts reserved.