PP/EPDM‐based thermoplastic dynamic vulcanizates with organoclay: morphology, mechanical and viscoelastic properties

Dynamically vulcanized nanocomposite thermoplastic vulcanizates (NC‐TPVs) based on ethylene‐propylene‐diene rubber (EPDM) and melt intercalated hybrid of poly(propylene) (PP)/maleic anhydride grafted poly(propylene) (PP‐g‐MA) with organo‐modified montmorillonite (org‐MMT) were prepared. X‐ray diffraction (XRD) analysis and scanning electron microscopy (SEM) examination have been performed to evaluate the extent of the intercalation, as well as to characterize the microstructure developed during dynamic vulcanization. The organocaly was better intercalated and dispersed in the PP matrix of the NC‐TPV samples at low clay contents. The NC‐TPV samples showed a matrix‐disperse type of morphology in which the crosslinked EPDM particles appeared in the form of agglomerates covered by a layer of nanocomposite PP (NC‐PP). The NC‐TPV samples exhibited higher elastic modulus compared with similar but unfilled TPV sample in spite of the lower crystallization degree for the former. The storage modulus (G′) of the molten NC‐TPV proved to be highly frequency dependent. This was assigned to the formation of a nanoclay network structure by the NC‐PP covered EPDM rubber particles.