MORPHOLOGY, MECHANICAL PROPERTIES AND FAILURE MODE OF THERMOPLASTIC ELASTOMERS FROM BLENDS OF POLY(PROPYLENE) AND ETHYLENE VINYL ACETATE RUBBER.

Morphology and mechanical properties of blends of poly(propylene) (PP) and ethylene vinyl acetate (EVA) thermoplastic elastomer have been studied with special reference to the effect of blend ratio. Morphological investigations of the blends showed a two phase system in which rubber phase remained as dispersed particles in the continuous PP matrix at lower proportions but as the proportion of the rubber is increased beyond 50%, this phase also formed a continuous phase. The mechanical properties of the blends were found to be strongly dependent on the proportion of PP in the blend. The effect of dynamic crosslinking of the elastomer phase on the mechanical properties of the system was also studied. In order to understand the mechanism of failure, tensile failure surfaces have been examined by scanning electron microscopy.