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 degrees 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 (t90), scorch time (tS2), maximum torque (MH), and minimum torque (ML) 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. (C) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013