RHEOLOGICAL PROPERTIES, TENSILE PROPERTIES, AND MORPHOLOGY OF PP EPDM/IONOMER TERNARY BLENDS/

The theological and tensile properties and the morphology of polypropy lene(PP)/ethylene-propylene-diene terpolymer (EPDM)/ionomer ternary bl ends were investigated, using a rheometric dynamic spectrometer (RDS), a dynamic mechanical thermal analyzer (DMTA), a tensile tester, and a scanning electron microscope (SEM). Two kinds of poly (ethylene-co-me thacrylic acid) (EMA) ionomers, neutralized with different metal ions (Na+ and Zn++), were used. Blends were melt-mixed, using a laboratory internal mixer at 190 degrees C. The composition of PP and EPDM was fi xed at 50/50 by wt % and the EMA ionomer contents were varied from 5 t o 20 wt %, based on the total amount of PP and EPDM. It was found that the ternary blends, containing Na-neutralized ionomer, showed conside rably different theological properties and morphology as compared to t he PP/EPDM binary blend, due to the compatibilizing effect of the iono mer for PP and EPDM, while the ternary blends, containing the Zn-neutr alized ionomer, did not. The compatibilizing effect was most prominent at 5 wt % of ionomer concentration. (C) 1994 John Wiley & Sons, Inc.