Solution polymers, comparison

E. Evans and D. Needham Attraction Between Lipid BUayer Membranes in Concentrated Solutions of Nonadsorbing Polymers Comparison of Mean-Field Theory with Measurements of Adhesion Energy. Macromolecules 21, 1822 (1988). 

This increase in viscosity is all the more pronounced when the molecular weight of polymers is high. In Figure 6, is plotted against the concentration ratio, r, for the couple PAA-ISo OOO/PEO-750 000. In this system, when a < 3%, phase separation occurs, bulk solid particles appear and precipitate. So, no viscosity measurement is possible. For a 4% the specific viscosity of the mixture is very higher than the sum of viscosities of the two individtial polymer solutions. The comparison may be easier if we define another parameter the gain in viscosity, g, which is given by the relation ... 

Here is Boltzmann s constant, or the gas constant per molecule, R/Nq, where No is Avogadro s number (or Na + Nb for one mole of solution) and va and are the volume fractions of solvent and polymer. Comparison of Eq. (2.76) with the entropy of mixing presented earlier in the chapter by Eq. (2.30) shows that they are similar in form, except that now the volume fractions of the components, va and vg, are found to be the most convenient way of expressing the entropy change for polymers, rather than the mole fraction used for most small molecules. This change arises from the differences in size between the large polymer molecules and the small solvent molecules which would normally mean mole fractions close to unity for the solvent, especially when dilute solutions are being studied. 

The modified FETs were tested for their pH response and stability in contact with aqueous solutions. For comparison a physically attached polymer (VE) was included in these experiments (16). The results given in Figure 2 show that the pH sensitivity can be eliminated almost completely with acrylate polymers (ACE), polybutadiene (PBD) and also with the physically attached VE polymer. The latter, however, is not stable in time and a pH sensitivity similar to the untreated Si02 gate oxide returns after S days. The structures of the polymers are given in Scheme 1. 

As a resume the rheological responses of MCLCP solutions (in comparison with conventional polymer solutions) to the most important variables are shown (qualitatively) in the comprehensive Fig. 16.36. 

To conclude this section we will simply note that the relationship given above in Equation 11-36 does not work well for polymer solutions. A comparison of calculated values of x to those obtained experimentally has led to the suggestion that a fudge factor df about 0.34 be included (Equation 11-39) ... 

Kratohvil JP, Hsu WP, Jacobs MA, Aminabhavi TM, and Mukunoki Y. Concentration-Dependent Aggregation Patterns of Conjugated Bile-Salts in Aqueous Sodium-Chloride Solutions—a Comparison between Sodium Tau-rodeoxycholate and Sodium Taurocholate. Colloid Polymer Sci 1983 261 781-785. 

Freed, K. R, Wang, S. Q., Roovers, J., and Douglas, J. R, Partial draining and universality of dilute solution polymer dynamics comparison of theory and experiment. Macromolecules, 21,2219-2224(1988). 

Figure 7.72 illustrates a large number of glass transition data of polymer solutions with comparisons to the Gibbs-DiMarzio (DM), Fox (F), and Schneider (S) equations described in Fig. 7.69 [30]. The upper left displays two sets of literature data on poly(vinylidene fluoride)-poly(methyl methacrylate) solutions (B,A). The glass transition shows a positive deviation from simple additivity of the properties of the pure components, which can only be represented with the help of the indicated interaction parameters of the Schneider equation. The lower left set of data illustrates poly(oxyethylene)-poly (methyl methacrylate) solutions (, o). They are well described by all three of the equations, indicating rather small specific interactions and great similarity between volume and entropy descriptions.

According to the measurement of DSC, exothermic reaction of lithium metals and polymer electrolytes is low in comparison with the electrolytic solution. Polymer electrolytes are effective for preventing lithium dendrite. This fact means that lithium metal can be used as the negative electrode by using polymer electrolytes. Furthermore, the polymer electrolyte is expected as a separator because of the sufficient high mechanical strength. 

For soluble polymers, comparison with their solution spectra offers the simplest means to assign the resonances in their CPMAS/DD solid-state spectra. On the other hand, those polymers that cannot be dissolved, melted or sufficiently swollen to provide high-resolution liquid-state spectra for comparison, can be observed in the solid with methods comparable to those developed for editing solution-state spectra. It is easier to describe these methods with the aid of a qualitative understanding of how the dilute C and abundant spins interact in a typical solid, organic sample. 

The properties of the microenvironment of soluble synthetic polymers such as polymethacrylamide (PMA), poly(2-hydroxyethyl methacrylate) (PHEMA), poly(2-vinylpyridine) (P-2VP), poly(4-vinylpyridine) (P-4VP), poly(methyl methacrylate) (PMMA), poly(butyl methacrylate) (PBMA), polystyrene (PS), poly(4[5]-vinylimidazole) (PVIm), and poly(N-2-hydroxypropyl methacrylamide) (PHPMA) and cross-lined polymers were studied by the shift and shape of the band in electronic spectra of a solvatochromic "reporter" molecule embedded in polymer chains. Preferential interaction of parts of the polymer molecule with a reporter and the shielding of interactions between solvent molecules and a reporter molecule of a polymer causes a shift and broadening of its solvatochromic band. This shift is mechanistically interpreted as a change in the polarity of the microenvironment of a polymer in solution in comparison with polarity of the solvent used. 4-(4-Hydroxystyryl)-N-alkylpyridinium-betaine, spiropyran-merocyanine, and l-dimethylamino-5-sulfonamidonaphthalene (Dansyl) reporters were used. In almost all cases the polarity of the polymer microenvironment was lower than that of the solvent. At the same time, the dependence of the nature of the environment on the distance of the reporters from the polymer chain was studied. 

Hegde, G. A. Chang, J.-F. Chen, Y.-L. Khare, R., Conformation and Diffusion Behavior of Ring Polymers in Solution A Comparison Between Molecular Dynamics, Multiparticle Collision Dynamics, and Lattice Boltzmann Simulations. J. Chem. Phys. 2011,135,184901. 

Annable T, Buscall R, Ettelaie R, Whittletone D. The rheology of solutions of associating polymers comparison of experimental behavior with transient network theory. J Rheol 1993 37 695-725. 

The polymer, when adsorbed from viscous solutions assists in the reduction in the coefficient of friction (Fig. 1) under the boundary- and mixed-lubrication conditions of pin-on-disk tribometry. The reduction in the friction was observed to be about 60% (from 0.25 to 0.1) at 0.1 mm/s when the polymer was adsorbed at the interface from 50% v/v HEPES-glycerol solution in comparison to a similar system with no polymer at the interface. The coefficient of friction also appears to converge at high speed (150 mm/s) in the presence of polymer for all HEPES-glycerol mixtures, indicating no effect of the polymer on friction as the surfaces become completely separated by a fluid film. 

GRA Graham, P.D., Barton, B.F., and McHugh, A.J., Kinetics of thermally induced phase separation in ternary polymer solutions, n. Comparison of theory and experiment, J. Polym. Sci. PartB Polym. Phys., 37,1461,1999. 

Abstract This chapter discusses the potential of fluorescence correlation spectroscopy (PCS) to study polymer systems. It introduces the technique and its variations, describes analysis methods, points out advantages and limitations, and summarizes PCS studies of molecular and macromolecular probes in polymer solutions, polymer gels, polymer nanoparticles, and polymeric micellar systems. In addition, a comparison with other experimental methods is presented and the potential of a combination with simulations discussed. 

A study [17] has been made of the effect of a dialyzed styrene-acrylate copolymer latex on the foam and the resistance to antifoam of three different surfactants—SDS, aerosol OT (sodium bis-diethylhexyl sulfosucdnate), and Triton X-100 (OP.EOjq)— all at a nominal concentration of 0.03 M. The polymer particles were dispersed in the surfactant solutions at a proportion of 25.5 wt.%. Adsorption of the surfactant onto the polymer particles significantly reduced the concentration of free surfactant in solution. A comparison was therefore made between the foam and resistance to antifoam behavior of the latex polymer-containing surfactant solution and a surfactant solution at the same depleted surfactant concentration, but containing no polymer. These depleted solutions were all submicellar—from about 80% to 99.9% of the surfactant (depending on the surfactant) was lost by adsorption onto the polymer-water surface. 

Another comparison is given in Figure 10 which shows the stress-deformation curves for polymer films containing polar or nonpolar functional monomers and prepared by solution or emulsion polymerization. In the case of N-methylol methacrylamide, the latex polymer was again much stronger than the solution polymer. In the case of the nonpolar glycidyl methacrylate (6MA) the polymerization method made little difference in the film strength. 

Right change in relative solution viscosity (comparison of throughput times for polymer solution and pure solvent, see Section 2.1.3.3.3.1)... 

Fig. 26.9 Temporal stability of the effective second harmonic coefficients of two samples monitored at 100°C. BPAZO/APAN represents a poled/cured polymer film that was prepared from an APAN-doped BPAZO polymer solution. For comparison, a poled/cured BPAZO sample was investigated concurrently.

The pressure transient tests provided a means of quantitatively determining in situ polymer effectiveness. The pressure response during polymer injection compared to the pressure response prior to beginning injection of any polymer solution was related to the increased resistance to flow because of the added polymer. Comparison of these pressure responses would measure the resistance factor. Similarly, comparison of the pressure response after brine has displaced polymer solution from the near well region to the initial pressure response gave a measure of the residual resistance. 

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