Microstructure and properties of PET/EPDM, EPDM-g-MA/organoclay ternary hybrid nanocomposites: effect of blending sequence

Poly(ethylene terphthalate) (PET)/organomontmorilonite (OMMT)/maleic anhydride ethylene-propylene-diene rubber (EPDM-g-MA) nanocomposites were prepared via melt blending of the ingredients in a Haake Rheocord mixer. To make the hybrid composites, four different blending routes were examined: 1) preparing EPDM/EPDM-g-MA (EPMA)/organoclay nanocomposite and then blending it with PET, (S-1), 2) dispersion of organoclay in PET and then blending it with EPMA, (S-2), 3) blending PET with EPMA and then mixing it with organoclay, (S-3), 4) blending PET, EPMA and organoclay in a single process, (S-4). The microstructure of the PET/(EPMA)/organoclay ternary hybrids were characterized by X-ray diffraction (XRD) and Transmission Electron Microscopy (TEM). The result showed that the blending sequence greatly affects the dispersion of organoclay in the polymer matrix as well as the microstructure of the blends. Mechanical behavior of the blends including tensile and impact properties were also studied. Results revealed that PET/ (EPMA)/organoclay nanocomposites made by mixing sequence, S1, has the maximum tensile and impact strength among the others. This was attributed to its fine "Sea-Island" morphology and good dispersion of the organoclay in the continuous PET matrix.