Polymer viscosity affected

Solution Properties. Typically, if a polymer is soluble ia a solvent, it is soluble ia all proportions. As solvent evaporates from the solution, no phase separation or precipitation occurs. The solution viscosity iacreases continually until a coherent film is formed. The film is held together by molecular entanglements and secondary bonding forces. The solubiUty of the acrylate polymers is affected by the nature of the side group. Polymers that contain short side chaias are relatively polar and are soluble ia polar solvents such as ketones, esters, or ether alcohols. As the side chaia iacreases ia length the polymers are less polar and dissolve ia relatively nonpolar solvents, such as aromatic or aUphatic hydrocarbons. 

Fiber orientation uniformity is also affected by small-scale or timewise variations in polymer viscosity, related to breakage of polymer chains during the extrusion process. The degradation occurs as a result of residual moisture that immediately reacts to break chains, and by thermal degradation that occurs more gradually over time. Different residence times and temperature histories within the laminar flow streamlines lead to different viscosities, and hence different average orientation levels in the different fibers. 

Salinity is essential for all chemical processes. It directly affects polymer viscosity, and it determines the type of microemulsion a surfactant can form. Salinity effects in waterflooding, in both sandstone and carbonate reservoirs, have recently drawn research interest. This chapter briefly discusses sahnity and ion exchange. At the end of this chapter, the sahnity effects on waterflooding in sandstone and carbonate reservoirs are summarized. 

Viscosity is the most important parameter for polymer solution. As mentioned earlier, hydrolyzed PAM, or HPAM, is the most used polymer in enhanced oil recovery. Some of factors which affect polymer viscosity are discussed next. 

Tan s experiments showed that the polymer would be more stable if it is under thermal degradation when the temperature is gradually increased so that the oxygen is consumed at low temperatures. However, the initial polymer viscosities were different in his experiments (57.8 mPa s at 75°C constant temperature compared with 77.5 mPa s under the temperature gradient). The water TDS was 362.6 mg/L, and sand was used in the tests. Tan tried to imitate the actual thermal degradation conditions. He also observed that oil did not affect the polymer thermal stability. 

Selection of the fluoropolymer depends on the end use requirements, part design, and process conditions. Viscosity of the molten pol5nner has a great influence on the transfer rate into the cavity. Temperature changes can alter polymer viscosity as long as it has sufficient thermal stability in the given temperature range. Cleanliness of the melt can affect the quality of the part and thermal stability of the molten resin. 

Indeed, Teramoto and co-workers [Sato et al., 1991, 2003 Ohshima et al. 1995] have pointed out that the viscosity of stiff-chain polymers is affected dramatically by chain flexibility. To illustrate this, in Figure 1.15, Sato et al. [2003] compare... 

Polymer concentration affects particle size and morphology because it influences polymer chain entanglements and solution viscosity. The size of the particle generally decreases as the polymer concentration decreases because of the decrease in the fraction of solid material for a defined volume of solution. A further decrease in concentration creates irregular or biconcave particle shapes. 

Knowledge of the molar mass and of the molar mass distribution of a polymeric material is indispensable for scientific studies and for many technical applications of polymers. They affect the solution and melt viscosity, the self-assembly behavior, the processability, and the resulting mechanical properties tremendously. Therefore, we will give a short introduction into methods that allow us to determine the required information. Roughly, the methods developed for the determination of molecular weights are subdivided into absolute and relative methods ... 

All in all, then, extensional viscosity seems to be the crucial property, even though the polymer apparently affects some flows by altering its shear stability. 

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