The rheology and morphology of four sets of binary blends of polyethylene s
ynthesized with metallocene catalysis (metallocene polyethylene: MCPE) with
polyolefins prepared using Ziegler-Natta catalysts have been investigated.
The blend systems are MCPE with high density polyethylene (MCPE-HDPE), pol
ypropylene (MCPE-PP), poly(propylene-co-ethylene) (MCPE-CoPP), and poly(pre
pylene-co-ethylene-co-1-butylene) (MCPE-TerPP). Cole-Cole plots [storage me
lt viscosity (eta') versus loss melt viscosity (eta ")], plots of the dynam
ic storage modulus (G') versus the dynamic loss modulus (G "), and plots of
the log melt viscosity (eta*, eta', and eta ") versus blend compositions w
ere constructed. The morphology of the blends after microtoming and etching
was studied. The phase morphology of MCPE-HDPE appeared homogeneous, where
as the other three blends were heterogeneous. Rheological and morphological
investigations indicated that the MCPE-HDPE blend was miscible, but the ot
her three blends were immiscible in the melt as well as in the solid state.
These observations can be rationalized in terms of the similarity of the c
hemical structures of the polyolefins.