DYNAMIC MECHANICAL-PROPERTIES OF THERMOPLASTIC ELASTOMERS FROM BLENDS OF POLYPROPYLENE WITH COPOLYMERS OF ETHYLENE WITH VINYL-ACETATE

Thermoplastic elastomers from blends of ethylene-vinyl acetate copolymer and polypropylene have been prepared by melt blending in a Brabender Plasticorder. Dynamic mechanical properties such as storage modulus, loss modulus and damping properties were studied over a wide range of temperatures. The effects of blend ratio and dynamic crosslinking of the elastomer phase on the dynamic mechanical properties have also been investigated. The morphology of the blends has been studied by scanning electron microscopy. Both microscopy and dynamic mechanical analysis indicate that the blends are immiscible and they have a two-phase structure. Attempts have been made to correlate the dynamic mechanical properties with the morphology of the system Various composite models have been used to fit the experimental viscoelastic data.