Melt Rheology of Binary Blends of Metallocene Polyethylene with Conventional Polyolefins

Abstract

The melt rheology of the binary blends of metallocenepolyethylene (MCPE) (polyethylene synthesized by metallocene catalyst) with conventional polyolefins prepared using the Ziegler-Natta catalyst was investigated the blend pairs are MCPR with high densitly polyethyene (MCPE-HDPE), polypropylene (MCPE-PP), poly(propylene-co-ethylene) (MCPE-Co-PP), and poly(propylene-co-ethylene-co-1-butylene) (MCPE-TerPP), The analysis was based on three methods. The first analyzed the shape and diameter of the loss melt viscosity (η). representing the Cole-Cole plot. The second was based on the slopes in logarthmic plots fo the dynamic storage modulus (G') versus the dynamic loss modulus (G) Between the blend compositions and the pure componets. The third analyzed the deviation of the plot of the log complex viscosity (log η*), log η' and log η versus the blend compositions from the linearity. As a conequence, the MCPE-HDPE blend showed semi-sircular curves with the same diameter in the Cole-Cole plot, linearity in the slope of the log G' versus log G between the pure components and the blend compositions, and the rule of the mixtures between the milt biscosity and the blend compositions. In contrast, the other theree blends showed a different manner. Accordingly, the MCPE-HDPE blend is miscible, however, the other blends are not, which may result from the similar chemical strucure of the ethylene wnit between the main and the side chain This interpretation of the melt rheology agrees well with the morphology.