Abstract: Effects of particle size and content of calcium carbonate, the type and dosage of dispersant resin, and processing temperature on the rhcological behavior of the heavily loaded calcium carbonate masterbatch were investigated using a rotating rhcometer with parallel plate geometry. Two "shear thinning" regions were observed from the rhcological curves, with one in the low shear rate region being attributed to the collapse of interface combination between the filler and resin, and the other being related to the di、一entanglement and orientation of polymer chains in the high shear rate range. The zero shear rate viscosity of the masterbatch was much larger than that of PE-LLD and increased rapidly with increasing filler content and/or decreasing particle size. The apparent viscosity in high shear rate region showed little change with filler size, but dramatically decreased with the addition of dispersant resins.The flow activation energy of the mastcrbatch was 25 .7KJ/mol，close to that of PE-LLD.

Key words: masterbatch with high loadings of calcium carbonate, rhcological behavior, rotating rhcometer with parallel plate geometry