Ethylene–propylene–rubber (EPR)/polydimethylsiloxane (PDMS) binary polymer blends: Morphology and viscoelastic properties

Melt mixed blends of ethylene–propylene–rubber (EPR) and polydimethylsiloxane (PDMS) were studied with regard to the composition dependence of the dynamic viscoelastic properties in relation to their morphology. Differential scanning calorimetry, scanning electron microscopy, and dynamic mechanical analysis (DMA) were used together with theoretical predictions to characterize the blends. The investigation of the viscoelastic properties showed significant improvement of the mechanical properties of the blends following the increase of the EPR content. The association of DMA results and theoretical predictions indicated that the studied blends consisted of dispersed PDMS in a matrix of EPR over the whole composition range. The microscopy study of the blends also supports these morphological conclusions. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 2240–2249, 2004