Polymers rheological effects

With nonadsorbing polymer, rheological effects of similar magnitude accompany the phase transitions described earlier (Patel and Russel, 1989a,b). Since macroscopic phase separation takes weeks or months, rheological measurements performed within a few days on samples formulated within the two-phase region, with — Q>miJkT 2 - 20, detect a metastable structure that changes little over time. The systems respond as flocculated dispersions, but the microstructure recovers relatively quickly to a reproducible rest state after shear. Hence these weakly flocculated dispersions are quite tractable materials. [Pg.222]

Associative polymers, rheology effect, 9 Atomic force microscope, measurement of steric exclusion forces, 266-277... [Pg.283]

Modeling the Effect of Polymer Rheology on the Performance of Underwater Pelletizers... [Pg.132]

One of the common problems associated with underwater pelletizers is the tendency of the die holes to freeze off. This results in nonuniform polymer melt flow, increased pressure drop, and irregular extrudate shape. A detailed engineering analysis of pelletizers is performed which accounts for the complex interaction between the fluid mechanics and heat transfer processes in a single die hole. The pelletizer model is solved numerically to obtain velocity, temperature, and pressure profiles. Effect of operating conditions, and polymer rheology on die performance is evaluated and discussed. [Pg.132]

The polymer rheology is modeled by extending the usual power-law equation to include second-order shear-rate effects and temperature dependence assuming Arrhenius type relationship. [Pg.137]

The effect of polymer rheology on the pressure drop is shown in Figure 10. Top curve is for a polymer with low melt index (1.03), middle curve is for medium melt index (10.5), and the bottom curve represents a polymer with... [Pg.141]

Kammer, H. W., Kressler, H. and Kummerioewe, C Phase Behavior of Polymer Blends - Effects of Thermodynamics and Rheology. Vol. 106, pp, 31-86. [Pg.210]

Vinogradov GV, Yanovsky YuG, Isayev AI (1970) Effect of vibrations upon polymers. In Vinogradov GV (ed) Progress of polymer rheology. Himiya, Moscow, p 79... [Pg.78]

This section contains two primary topics. The first is polymer rheology, which is concerned with how polymeric materials flow when they are placed under stress. Also of interest are the mechanical properties of polymers, particularly their elasticity. The combination of viscous effects with elastic phenomena is called viscoelasticity. [Pg.50]

Wu S (1987) Formation of dispersed phase in incompatible polymer blends interfacial and rheological effects. Poly Eng Sci 27(5) 335-343... [Pg.140]

Phase Behavior of Polymer Blends -Effects of Thermodynamics and Rheology... [Pg.31]

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