Morphological evolution and properties of thermoplastic vulcanizate/organoclay nanocomposites

Abstract

Nanocomposites composed of organoclay and thermoplastic vulcanizates (TPVs) based on uncompatibilized or compatibilized polypropylene (PP)/ethylene–propylene–diene rubber (EPDM) blends were prepared in this study. The morphology of the nanocomposites was studied with wide‐angle X‐ray diffraction and transmission electron microscopy, which suggested that the addition of the compatibilizer played a key role in determining the morphology of the composites because of their interaction with the clay surface. Scanning electron microscopy study indicated the changes in the morphology of the rubber particles. Dynamic mechanical analysis was also applied to the analysis of these phenomena. Moreover, for nanocomposites with uncompatibilized PP/EPDM blends as the matrix, the samples showed tensile enhancement compared with neat TPV. Although the addition of the compatibilizer changed tensile properties of the composites in a rather different trend, the tensile modulus increased dramatically when the compatibilizer was added. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40618.

Effects of compounding procedure on morphology development, melt rheology, and mechanical properties of nanoclay reinforced dynamically vulcanized EPDM/polypropylene thermoplastic vulcanizates

“…In comparison with the previously reported methods , EPDM rubber, EPDM‐ g ‐MA, and nanoclay were simultaneously fed into an internal mixer. After 2 min, PP was added and when constant torque was achieved, the curing agent was incorporated.…”

“…Li et al showed that when nanoclay is added to EPDM in an internal mixer and then PP is added, the product has higher mechanical strength compared with products in which PP, EPDM, and clay are added simultaneously into the internal mixer , but they added the curing system into a mixture of PP and EPDM while mixing and did not use compatibilizer to disperse clay in the EPDM phase. Babu et al studied the effect of mixing sequence on peroxide cured TPV and reported that adding ethylene octane copolymer (EOC) curative masterbach to the molten PP yields higher mechanical properties .…”