Viscosity polymer effect

The interaction between alkali and polymer, to be discussed in this section, includes alkaline effect on polymer viscosity, polymer effect on alkafine/oil IFT, and alkaline consumption in alkaline-polymer systems. 

The presence of inorganic salts in solutions of poly(ethylene oxide) also can reduce the hydrodynamic volume of the polymer, with attendant reduction in intrinsic viscosity this effect is shown in Figure 7. 

The viscous shear properties at any given shear rate are primarily determined by two factors, the free volume within the molten polymer mass and the amount of entanglement between the molecules. An increase in the former decreases the viscosity whilst an increase in the latter, i.e. the entanglement, increases viscosity. The effects of temperature, pressure, average molecular weight, branching and so on can largely be explained in the these terms. 

TXRF was used to characterize high-viscosity polymer dispersions [83], with special attention being paid to the different drying techniques and their effect on the uniformity of the deposited films. TXRF was also used as a means to classify different polymers on the basis of their incoherently scattered peaks [84], Dispersive XRF has been used to assess the level of aluminum in antacid tablets [85]. 

There are some limitations to this technique. First, proper mixing can only be achieved with dilute, low viscosity polymer solutions (perhaps a few percent polymer by mass), so the final films are at most a few hundred nanometers thick. This can be a problem if confinement will create undesired effects in the blend behavior. 

Time Effect of Gegenion on Percent Conversion and Intrinsic Viscosity. The effect of gegenion on percent conversion to polymer and on intrinsic viscosity of the polymers is shown in Table V. Duplicates and runs with fresh catalyst solution all followed the same pattern. In the experiment using the BF4 gegenion at 10 times the usual concentration, the final conversion is increased considerably, although it still falls 2% below the equilibrium conversion. 

It was reported that most cations increase the viscosity and most of anions decrease the viscosity of povidone K 90 solutions [530]. Some polymers such as carragheenan show a synergistic viscosity increasing effect with the high-molecular povidone K 90. 

In ASP flooding, alkaline, surfactant, and polymer have different effects on relative permeabilities. Table 13.2 shows our attempt to summarize these effects compared with waterflood. From Table 13.2, we can see that the effect of alkaline flood in terms of emulsification is similar to the polymer effect, whereas its effect in terms of IFT is similar to the surfactant effect. Less rigorously, we may say that only polymer reduces k, and only surfactant reduces IFT. In ASP flooding, the viscosity of the aqueous phase that contains the polymer is multiplied by the polymer permeability reduction factor in polymer flooding and the residual permeability reduction factor in postpolymer water-flooding to consider the polymer-reduced k effect. Then we can use the k curves (water, oil, and microemulsion) from surfactant flooding or alkaline-surfactant flooding experiments without polymer. 

Emulsion stability is affected by temperature, continuous phase viscosity, droplet sizes and their distribution, interfacial tension (IFT), and interfacial film properties. Some of these effects were discussed in the preceding section. This section discusses the effects of viscosity, polymer, IFT, and interfacial film. 

Becanse emulsion stability is affected by continnous phase viscosity, polymer plays an important role in stabilizing emnlsions. The effect of polymer in the W/0 type of emulsions is different from that in the OAV type. Fignre 13.19 shows the polymer (HPAM) effect on a W/0 emulsion stability that is represented by the percent of water separated from the emnlsion at different times. In this case, the oil was kerosene. As the polymer concentration was increased, the water/oil emnlsion stability increased (less percentage of water separated). W/0 emulsion stability mainly depends on the strength of the oil film between water droplets. The oil film sfrength is determined by... 

B. (3.0) Ratio Polymers Effect of Urethane Group Concentration. Figure 5 shows the polymerization viscosity-time-temperature relations for a (3.0 ratio) thermoplastic poly(ester-urethane) elastomer, Polymer 9. This polymer was made from reactants VI, IV, and X (Table I) the polyester glycol component being intermediate acid number PTAd (0.30). 

Several types of dispersions show strain rate thinning, and a quantitative explanation is not easily given. We will briefly consider two cases. The first one concerns shear flow. As discussed (above, Factor 4), anisometric particles show rotational diffusion and thereby increase viscosity. This effect will be smaller for a higher shear rate when the shear-induced rotation is much faster than the diffusional rotation, the latter will have no effect anymore. The shear rate thinning effect is completely reversible. Something comparable happens in polymer solutions (Section 6.2.2). 

The utilisation of low molecular weight transfer agents, which control the molecular weight of the carbocatenary vinylic polymer, is a very effective way to obtain low viscosity polymer dispersions at high solid concentrations. 

Dependence of the photoinduced viscosity change on the structure of the polymer (effect of the R group)... 

On the other hand, in a non-Newtonian fluid, the viscosity depends on the shear rate. Besides showing very high non-Newtonian viscosities, polymers exhibit a complex viscoelastic flow behavior, that is, their flow exhibits memory , as it includes an elastic component in addition to the purely viscous flow. Rheological properties are those that define the flow behavior, such as the viscosity and the melt elasticity, and they determine how easy or difficult is to process these materials, as well as the performance of the polymer in some applications. The rheology of the polymers and its effect on the processing of these materials are studied in Chapters 22 and 23. 

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