Rheology of mica‐reinforced polyethylene melts

Seven samples of HDPE containing 0, 2, 5, 10, 25, 40 and 60 weight percent of mica were prepared on a roll mill at 200°C. The samples were tested at T = 150, 170, 190 and 210°C for a wide range of rate of deformation from 10 −2 to 2 × 10 4 s −1 . Both capillary and rotational rheometers were used. The samples were found to be thermally stable. The results indicate that η, G ′, and G ″ increase with mica content for the whole range of deformation rates. The relaxation time spectrum for the sample containing 60 weight percent of mica showed a particulate contribution. The zero shear viscosity was discussed in terms of suspension theories.