Fibril or particulate fillers used to reinforce polymeric composites are often inorganic, so, as two dissimilar materials cannot compatibilize with each other, the problem of adherence always exists. To solve this problem a third material can help as a coupling agent. A coupling agent should have the ability to adhere to both surfaces by means of different functional groups. Silane coupling agents are frequently used because of several outstanding aspects they have. This review is a survey on these coupling agents used in composites.

The offline Microstructure of nanocomposites based on Poly-Propylene (PP), Ethylene-Propylene Diene Monomer (EPDM) and Cloisite 15A along the twin screw extruder barrel was investigated by X-Ray diffraction, Transmission Electron Microscopy (TEM) and rheological measurements. To assess the effect of screw zones, the microstructural development of nanocomposites along the screw was investigated. Accordingly, dead-stop experiment samples were taken at four different positions of the extruder after abruptly stopping the machine and opening the barrel. Effect of clay loading on the evolution of morphology in the extruder was studied. X-Ray diffraction results showed that at lower clay contents (up to *7 wt.%), the intercalation process is independent of screw geometry and accomplishes as soon as the matrix is melted; and on the other hand, excessive melt mixing of the samples containing higher clay loadings (10 wt.%) might lead to the collapse of silicate layers and consequently poor degrees of intercalation/exfoliation. Results were confirmed by TEM micrographs and also XRD patterns of the nanocomposites sensitively detecting the microstructural changes of the samples.

In this article a review is presented of studies on polypropylene and ethylenepropylene-diene terpolymer nanocomposites, reported in the period from 1970 to 2007. The article has two major parts; first it discusses TPVs made up of a thermoplastic and a volcanizable elastomer, and second it explains about nanocomposite technology and its remarkable effects on the properties, morphology, and applications of TPVs.

Dynamically vulcanized thermoplastic elastomer (TPE) nanocomposites based on polypropylene (PP), ethylene-propylene diene monomer (EPDM) and cloisite 15A were prepared via direct melt mixing in a corotating twin-screw extruder. The mixing process was carried out with optimized processing parameters (barrel temperature 5 180 C; screw speed 5 150 rpm; and feeding rate 5 0.2 kg/hr). The formulation used to prepare the nanocomposites was fixed to 75/20/5 (PP/ EPDM/Cloisite V C 15A), expressed in mass fraction. Effect of mixing sequence on the properties of vulcanized and unvulcanized (TPE) nanocomposites prepared under similar conditions was investigated using X-ray diffraction (XRD) and a tensile testing machine. Results showed that the sequence of mixing does affect the properties of final TPE nanocomposites. Accordingly, nanocomposite samples prepared through mixing the preblended PP/clay masterbatch with EPDM phase, show better clay dispersion within the polymer matrix.