Compatibilization of PP/EPDM Blends via a Hexa Functional Coupling Agent and Peroxide During Reactive Extrusion

Isotactic polypropylene (PP) and ethylene-propylene-methylene-norbornene terpolymer (EPDM) were blended in a counter-rotating twin screw extruder in the presence of a peroxide initiator and a new multifunctional coupling agent (hexa(allylamino)cyclotriphosphonitrile (HAP)). The effects of free radical coupling reactions on the mechanical properties and morphologies of the resultant blends were evaluated. Blends that included both HAP and peroxide displayed an increase in low temperature impact strength. Tapping-mode atomic force microscopy(AFM) of the alloys revealed enhanced dispersion of EPDM within the PP matrix when compared to the base blends.