Interfacial Interactions in PP/MMT/SEBS Nanocomposites

Abstract

The intercalation capability of poly(styrene-b-ethylene butylene-b-styrene) (SEBS) in nanocomposites of isotactic polypropylene (PP) with 5 wt % of organically modified montmorillonite (C20A), prepared by melt blending, has been investigated. X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies have shown the presence of intercalated structures in the nanocomposite. In a previous research, we studied the intercalation capability of a commercial compatibilizer. 1 Those results, with the study we present in this work, allow us a better understanding of the mechanism of compatibilization and a deeper characterization of the structure and morphology of the nanocomposite. Scanning transmission X-ray microscopy (STXM) has been used. Because of the excellent chemical sensitivity and the high spatial resolution (∼40 nm) of this technique, we have proved that C20A is not in direct contact with the PP phase because the clay is always located inside the elastomer domains. The elastomer is surrounding the nanoclay, hindering the clay exfoliation and preventing its dispersion in the PP matrix. On the other hand, we have observed that the presence of the clay caused the SEBS particles to become elongated in shape and retarded the coalescence of the elastomer particles.

Compatibilizing action and localization of clay in a polypropylene/natural rubber (PP/NR) blend

“…34 The intensity of the directed beam that 11 solely contributes to the image contrast is reduced and such crystals appear relatively dark. Similar results have been observed by Martin et al 36,37 The inter diffusion of the interface as a result of this can be observed clearly from the TEM images (Fig. High resolution TEM studies indicate that clay is predominantly localized in the PP phase and a minor portion is localized at the interphase.…”

Polypropylene-blended organoclay nanocomposites – preparation, characterisation and properties

“…The addition of 5% of PP-g-MA in C20A and C30B shows optimum improved performance with the increase in the tensile strength of 22% and 14%, respectively. The reason may be due to high surface area of nanofillers, presence of tallow ammonium group, compatibilising agent, breaking up the large particles into fine nanoparticles which results in higher interfacial adhesion between TPO and clay [13][14][15][16][17]. Similar observations were reported for nylon-6 blended poly(ethylene-ran-propylene) rubber and polystyrene with polypropylene [18][19][20].…”

Melt Processing and Characterization of Nanocomposites of PP/Na+MMT Blending with Hyperbranched Polyester

“…As given in the literature, weight ratio 3:1 of commercial compatibilizers to clay shows better results of clay dispersion [33,34] , here in the present study we selected 15 phr of compatibilizers to compare the extent of dispersion. The morphologies of the composites processed with HBPE were different to a great extent from those of the sample prepared with PP-g-MA.…”