Compatibilization of bentonite filled ethylene‐propylene‐diene monomer composites: Effect of maleic anhydride grafted EPDM

Maleic anhydride grafted ethylene‐propylene‐diene monomer (MAH‐ g ‐EPDM) was prepared by peroxide‐initiated melt grafting of MAH onto EPDM using a HAAKE internal mixer at 180°C and 60 rpm for 5 min and it was used as compatibilizer to enhance the compatibility of EPDM/Bt composites. The composites were prepared using a laboratory scale two roll mill, model XK‐160 at room temperature. The addition of 10 parts per hundred rubber (phr) of MAH‐ g ‐EPDM into EPDM/Bt composite results in significantly improved tensile properties compared with the uncompatibilized EPDM/Bt composites. Curing behavior, tensile properties, solvent resistance, and the rubber‐filler interaction of compatibilized and uncompatibilized EPDM/Bt composites were investigated. The cure time ( t 90 ), scorch time ( t S 2 ), maximum torque ( M H ), and minimum torque ( M L ) of compatibilized composites were increased upon addition of MAH‐ g ‐EPDM. Compared with uncompatibilized EPDM/Bt composites, the tensile properties, solvent resistance, and rubber‐filler interaction of compatibilized EPDM/Bt composites were all improved. SEM micrographs of tensile fractured surfaces of compatibilized EPDM/Bt composites showed a better dispersion of Bt and interfacial adhesion between EPDM and Bt compared with uncompatibilized EPDM/Bt composites. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013