Associative polymers, rheology effect

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

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. 

In the trimer series, the hydrophobic domains in the fluorescence data reflect isocyanurate associations. The hydrophobe associations responsible for effective thickening occur at higher concentrations. Probe studies similar to those conducted in oxyethylene-oxypropylene block polymers (12, 13) are warranted. The difference of importance to the rheology of dispersed systems is likely related to the cohesiveness of the surfactant hydrophobe interaction (21). 

Soluble polymers have long been exploited to adjust the rheology of colloidal dispersions and new possibilities based on novel macromolecular structures continue to emerge. Here we review selectively the effects of grafted polymer, adsorbing homopolymer, associative polymers, and nonadsorbing polymer. 

Effect of Chemical Interactions on the Rheological Properties of Associating Polymers... 

Such characteristics of several other branched architectures have been examined [70]. The molecular compression behavior by branching allows high loading of the polymeric additives without the excessive viscosity enhancement associated with polymers. As we shall discuss in Section 13.3.6, the rheological effects of... 

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