Solution viscosity response

Figure 7. Solution viscosity response to salt as a function of polymer (0.75 mol% RAM) concentration.

It was seen that anionic surfactants interact with the positive charge of cationic polysaccharides even at concentrations well below the surfactant s cmc. There is a rapid increase in the viscosity of 1.0 wt% polyquaternium-10 solutions as the anionic surfactant begins to neutralize the charge on the cationic polymer (Fig. 26). As shown earlier (Fig. 22), this solution viscosity response is characteristic of the cationic HEC/anionic surfactant combination and does not appear to occur in the juxtaposed anionic cellulose/cationic surfactant combination. 

PPS is well-recognized for its exceptional chemical resistance. There are no known solvents for PPS below 200°C. A comprehensive survey of solvents for PPS has been published (115). Extreme conditions are required to dissolve PPS in both common and exotic solvents. Solution viscosity measurements are made difficult by this high temperature requirement. Inherent viscosity measurements are performed in 1-chloronaphthalene at 206°C at a concentration of 0.4 g of polymer per deciliter of solution. The inherent viscosity of PPS solutions shows a usefiil response to increa sing molecular weight. Table 2 shows a correlation of inherent viscosity measurements with melt flow measurements. 

Due to dieir compact, branched structure and to die resulting lack of chain entanglement, dendritic polymers exhibit much lower melt and solution viscosity dian their lineal" counterparts. Low a-values in die Mark-Houwink-Sakurada intrinsic viscosity-molar mass equation have been reported for hyperbranched polyesters.198 199 Dendrimers do not obey diis equation, a maximum being observed in die corresponding log-log viscosity-molar mass curves.200 The lack of chain entanglements, which are responsible for most of the polymer mechanical properties, also explains why hyperbranched polymers cannot be used as diermoplastics for structural applications. Aldiough some crystalline or liquid... 

There s another reason why the computed solution average temperature had decreasing accuracies in Tests 1, 2 and 3 respectively. The reason is that we started with increasingly viscous solutions, which caused the response time of the temperature measurement to increase rapidly. This response time becomes even more significant because as the solution viscosity increases there are significant rises in the reaction rates and temperatures. 

Electrostatic repulsion of the anionic carboxylate groups elongates the polymer chain of partially hydrolyzed polyacrylamides increasing the hydrodynamic volume and solution viscosity. The extensional viscosity is responsible for increased resistance to flow at rapid flow rates in high permeability zones (313). The screen factor is primarily a measure of the extensional (elonga-tional) viscosity (314). The solution properties of polyacrylamides have been studied as a function of NaCl concentra-tion and the parameters of the Mark-Houwink-Sakaruda equation calculated... 

Due to the high sensitivity of the viscometer, accurate readings of viscosity responses can be made with sample h gi values much less than 1.1. Therefore, saitple solutions of very low concentration can be analyzed in the viscometer to produce a single point intrinsic viscosity determination without the need of concentration extrapolation. As shown in Figure 7 for a polystyrene saitple, any h- u determination at the value of... 

S]. Another explanation could be changes in the dielectric constant in the region of the film, since the dielectric constant has an effect on conductivity responses for APM devices (see Section 3.3.4) [16,34]. In another study, a TSM was used with a conductivity electrode to make a sensitive probe of conductivity that had little dependence on solution viscosity and density [36]. In addition, the parasitic contribution to the static capacitance in TSM devices has been correlated with solution dielectric constant [11,12]. 

September 23, 1994, followed by 0.327 PV ASP flood, and 0.273 PV polymer drive and water drive. The ASP solution viscosity was 16 mPa s. During water preflush, the oil recovery before ASP was 31.63% from the SII1.3 layer. The response to ASP injection was observed in November 1994 (after 0.0693 PV of injection). The average water cut in the entire pilot area decreased from 82.7% to a low of 59.7%, and the daily oil production increased from 37 mVd toapeakof91.5 mVd. The water injectivity decreased from 1.75 mV(md-MPa), stabilized at about 1.42 mV(m-d-MPa), and then dropped to 1.19 mV(m d-MPa). In general, after an ASP slug is injected, flow resistance increases, and water injectivity decreases. The simulation prediction showed about 20% incremental oil recovery factor over waterflood. The early performance matched very well with the simulation prediction. In this pilot test, the simulator used was GCOMP. 

In the proceeding sections, emphasis has been placed on pH-responsive homopolymers whose conformational behavior is dictated by the hydrophobic to hydrophilic balance within the system. The switch in conformation is marked by a change in macroscopic properties, such as solution viscosity, over a narrow and characteristic pH range specific to that polymer which is important from a technological viewpoint. Manipulation of the switch to any desired pH has attracted much interest in the literature because this could lead to many more potential applications for the modified poly electrolyte. Synthetic strategies adopted to achieve this end have included simple copolymerization of an ionizable repeat unit with a hydrophobic monomer [20,27—43,1291 to form statistical copolymers and formation of block copolymers [71,158-180]. (A block copolymer consists of sequences of monomers A and B such as -(A) -(B)m or -(A) -(B)m-(A) , where n and m represent the number of repeat units.)... 

The process to make rayon begins with wood pulp or wood chips, usually from spruce or pine trees. The wood is treated with carbon disulfide (CS2), which converts cellulose in the wood to cellulose xanthate. The purpose of this step is to change an insoluble material (cellulose) into a soluble material (cellulose xanthate). The cellulose xanthate is then dissolved in sodium hydroxide (NaOH), a strong alkali, forming a thick, viscous solution. The viscosity of the solution is responsible for the name given to this method of making rayon, the viscose process. 

Minor amounts of carboxylic acid monomers are sometimes polymerized into vinyl-acrylic latexes, chiefly for introducing a viscosity response to changes in pH. Acrylic acid (AA) is also used for the pressure-sensitive adhesive market. Gajria and Tjayendran [41] studied the pH response of AA and methaciylic acid (MAA) modified VAc/BA latexes. Feeding the acid in the monomer feed as opposed to a water solution feed produced a greater viscosity response upon pH... 

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