Sulfonate solution viscosity

Certain mixtures of polymers have been shown to form complexes which exhibit substantially higher than expected solution viscosity under low shear conditions. Xanthan gum blends with guar gum (38, 39), sodium poly(styrene sulfonate) (40), polyacrylamide (41), sulfonated guar gum (38), sodium poly(vinylsulfonate) (40), hydrolyzed sodium poly(styrene sulfonate-co-maleic anhydride) (38), and poly(ethylene oxide) (41) and blends of xanthan gum and locust bean gum have exhibited substantially higher than expected solution viscosity (42, 43). 

In summary, these solution studies of sodium salts of lightly sulfonated polystyrene In tetrahydrofuran verify the presence of associating polymer behavior In lonomer solutions with nonionizing solvents. The results provide a molecular basis for the understanding of solution viscosity behavior. Individual lonomer colls are observed to retain constant dimensions while associating... 

A thermopolastic elastomer based on sulfonated-EPDM, S-EPDM, was developed in the 1970 s by Exxon and more recently by Uniroyal. Unlike the synthesis of the carboxylate ionomers described above, S-EPDM is prepared by a post-polymerization sulfonatlon reaction(28). Compared to the metal neutralized S-EPDM, the sulfonic acid derivative is not highly associated. The free acid materials possess low strengths and are less thermally stable. The metal salts of S-EPDM have properties comparable to crosslInked elastomers, but they do exhibit viscous flow at elevated temperatures. In the absence of a polar cosolvent, such as methanol, hydrocarbon solutions of the metal salts of S-EPDM are solid gels at polymer concentrations above several percent(31). With the addition of 1 to 5% alcohol the polymer solution becomes fluid with solution viscosities of the order of 10 to 100 poise. 

Similar solution behavior was reported(9-11) for sulfonate ionomers. Rochas eit al. (9) observed a polyelectrolyte effect for acrylonitrile-methallylsulfonate copolymers in DMF. Lundberg and Phillips(10) studied the effect of solvents, with dielectric constants ranging from c 2.2 to e 46.7, on the dilute solution viscosity of the sulfonic acid and Na-salt derivatives of sul-fonated polystyrene (SPS). For highly polar solvents such as DMF and dlmethylsulfoxide (DMSO, e 46.7) they observed a polyelectrolyte effect, but for relatively non-polar solvents such as THF and dioxane (c = 2.2) no polyelectrolyte effect was observed. Like Schade and Gartner, these authors concluded that polar solvents favor ionization of the metal sulfonate group while non-polar solvents favor ion-pair interactions. 

Solution Viscosity Behavior of Carboxylate and Sulfonate Ionomers. The solution behavior of sulfonated polymers has been described in some detail in a previous publication (13). It was shown in that study that... 

Figure 6. Solution viscosity of lightly sulfonated and carboxylated PS s as a function of cosolvent. Viscosity vs. hexanol level (%) 0.32 mol% S-PS ( ) 0.48 mol% C-PS (O) PS 3% concentration in hexanol/xylene.

Figure 10. Solution viscosity-temperature relation of S-PS and C-PS at low functional group levels (S-PS = 0.32 mol % sulfonate C-PS = 0.48...

Effect of Temperature on the Solution Behavior of Carhoxylate and Sulfonate lonomers. Based on the results above, a substantial difference in the solution behavior of carhoxylate and sulfonate ionomers might be expected as a function of temperature. Figure 10 illustrates the effect of temperature on the solution viscosity of carboxylated and sulfonated ionomers at very low sulfonate and carhoxylate content. At low polymer concentrations it is seen that the sulfonate system manifests a higher viscosity level in 1% hexanol/xylene solution. This is consistent with the dilute solution viscosity behavior. More importantly, at high polymer concentrations it is seen from Figure 10 that the 5% S-PS curve actually goes through a maximum, while the carhoxylate system decreases mono-tonically. These results are apparently attributable to the weaker ionic association in the carhoxylate case as compared to the sulfonate system. 

Information on microviscosity is obtained by studying the excimer forming capabilities of suitable fluorescent probes. The excimer, which is a complex of a ground state and excited state monomer, has a characteristic emission frequency. The intramolecular excimer formation for example, of 1,3-dinaphthyl propane (DNP), is a sensitive function of the microviscosity of its neighborhood. This property, expressed as the ratio of the excimer and monomer yield (/e//m) for DNP, has been determined for dodecyl sulfonate solutions and its adsorbed layer for the various regions of the adsorption isotherm (Fig. 4.18) (Somasundaran et al., 1986). Comparing the ratios thus obtained to the /e//m values of DNP in mixtures of ethanol and glycerol of known viscosities, a microviscosity value of 90 to 120 cPs is obtained for the adsorbed layer in contrast to a value of 8 cPs for micelles. The constancy of microviscosity as reported by DNP is indicative of the existence of a condensed surfactant assembly (solloids) that holds the probe. 

Biopolymers such as xanthan and scleroglucan exhibit many desirable properties 28,34,36) (i.e. temperature behavior and viscosity level),but they are not stable to microbial degradation [see ref. 8 in l ]. Cellulose in its water-soluble form, hydroxyethylcellulose (NEC), has good resistance to brine but the required concentration for a solution viscosity of 10 mPa s is too high. Poly(styrene-sulfonate) also has been investigated 33) [see ref. 14 in ], but its sensitivity to brine, its viscosity loss by aging, and the possibility of side-reactions limits its use in EOR. Polymers such as... 

The study revealed that the addition of isobutanol to dilute TRS 10-80 or TRS 10-410 petroleum sulfonate solutions did not influence significantly IFT, or surfactant partitioning but decreased interfacial viscosity and markedly reduced flattening time of oil drops and increased oil displacement efficiency, presumably by promoting coalescence of oil ganglia in porous media. 

Berthold, H., Matte, E., Mbrlein, J., Rose, F., Scholz, J., Werner, W. and Wirth, D., Preparation of alkane-sulfonate solutions with high viscosity from sulfochlorinated alkanes, German (East) DD 292,448 DD 292,449, 1991. 

Early attempts to characterise the molecular weight of PEEK were hindered by its lack of solubility. Solution viscosity is typically measured in concentrated sulfuric acid. This technique is useful for small samples and samples that may lack thermal stability but it is not as sensitive as melt viscosity. Much effort was put into gel permeation chromatography (GPC) of sulfonated PEEK and the determination of Mark-Houwink parameters. Relationships were determined between melt viscosity and molecular weight [40]. Melt viscosity is related to molecular weight by ... 

The mechanism and kinetics of the inverse emulsion polymerization of p-sodium styrene sulfonate was investigated using both oil-soluble and water-soluble initiators (53). Table XI gives the recipe used in these polymerizations. The p-sodium styrene sulfonate was dissolved in the water, and the solution was emulsified in the o-xylene using the Span 60 (sorbitan monostearate ICI America) emulsifier in some experiments, the benzoyl peroxide was dissolved in the o-xylene in others, the potassium persulfate was dissolved in the aqueous phase. The polymerizations were carried out at 40-70°. The rates of polymerization were measured dilatometrically, the molecular weights by solution viscosity, and the latex particle sizes by electron microscopy. 

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