Extensional flow of mica‐filled polyethylene

Abstract

Extensional flow of mica-filled high density polyethylene was studied at 150°C in a Rheometrics elongational rheometer. The constant strain-rate mode at a rate of to 1.0 s-', and the constant stress mode were used. The mica content was 0, 25, 40, and 60 weight percent. In both testing modes, the steady state elongational viscosities were obtained; those for the filled samples were about ten to twenty times larger than the shear viscosity at corresponding (low) rates of deformation.

Flow and flow orientation of composites containing anisometric particles

“…Similar conclusion can be drawn from the data presented in Fig. 9 for HDPE/mica system (24). The extensional flow tests for glass fiber-filled polymer melts, reported by White et d. ( Since elongational flow is irrotational, the particles should align themselves with the stress vector.…”

“…In extensional flow yield stress, T~,~. has been reported by White et al (19 to 21); by Kamal and Mute1 (22,23); and by Utracki et al (8,10,24). Yield stress is apparent in two (related) dependencies: (i) as a vertical displacement in the stress growth function at decreasing strain rates, and (ii) as a deviation from the Trouton rule at the extensional strain rate, i + 0.…”

“…For composites with initially random orientation of fibers or flakes, there must be a period of rearrangement. At higher loading this is accompanied with a very noisy stress signal observed for HDPE/mica (24) and PP/ glass fiber (23) systems.…”

A computerized system for measurement of transient and equilibrium extrudate swell

“…34* 35 To obtain a density, which matched the density of the melt at the test temperature, a mixture of 2 and 5 CS oils was used with all the low density polyethylenes (LDPE) and the polypropylene (PP) resins tested in this study. The exact proportion of these two components was defined experimentally.…”

Rheological properties of ionically crosslinked poly(propylene)‐type thermoplastic elastomers

“…Applying Cogwell's method 18 to their result as in the present study, increases with increasing the degree of crosslinking, which is a trend that is in agreement with the present experimental results. The elongational viscosity and its strain rate-softening increase with increasing filler content because of the effect of particulate filling on the change of elongational viscosity with elongational strain rate , for the HDPE/glass fiber system, 42 the PP/glass fiber system, 43,44 the polystyrene/carbon black, titanium dioxide, and calcium carbonate systems, 45,46 the HDPE/mica system, 47 and the polystyrene/carbon black system. 48 .…”