Poly relative viscosities

The relative viscosities at 25 C of solutions containing 12% wt/vol poly(vinylbutyral) in pure methanol (MeOH),... 

Fig. 9. Time dependence of the relative viscosity of 1 g/dl of poly(isopropyl isocyanide in dichloroacetic acid at 30° C A original sample, B repeat determination after recycling the...

Figure 2. Change in relative viscosity of poly-a,L-glutamic add ( ) and poly-

Furthermore, if what we want to determine is the frictional forces between a single polymer molecule and the solvent, then we need to make the measurements in dilute solution, so that there is no contribution from poly-mer/polymer interactions. In fact, just as in osmometry and light scattering, we measure the relative viscosity over a range of dilute solution concentrations and extrapolate to zero concentration. 

Solution viscosities are involved in quality control of a number of commercial polymers. Production of poly(vinyl chloride) polymers is usually monitored in terms of relative viscosity (tj/tjo) while that of some fiber forming species is related to IV [inherent viscosity, c ln(> /)/ )]. The magnitudes of these parameters depends primarily on the choices of concentration and solvent and to some extent on the solution temperature. There is no general agreement on these experimental conditions and comparison of such data from di I ferent manufacturers is not always straightforward. 

Figure 6.4 Relative viscosity rjr = rj/rjg verses reduced shear stress for latices of poly(methylmethacrylate) spheres of radii 85, 141, 204, and 310 nm, sterically stabilized by adsorbed triblock copolymer, poly(dimethylsiloxane)-polystyrene-poly(dimethylsiloxane), in silicone fluids of viscosity 7.98 cP and 44.1 cP at 30°C. The line is the fit from Eq. (6-14a). (From Choi and Krieger 1986, reprinted with permission from Academic Press.)...

Figure 7.9 Shear-stress dependence of the relative viscosity for dispersions in white spirit of acrylic copolymer particles of radius a = 157 nm at a volume fraction of p =0.40 for differing concentrations of nonadsorbing polyisobutylene polymer of molecular weight 411,000. The particles had been stabilized by addition of a comb-graft copolymer of PMMA backbone (which adsorbed to the particles) with non-adsorbing poly(12-hydroxystearic acid) teeth. The con-centrations (in weight per unit volume) of polyisobutylene are 1.0% ( ), 0.85%(B), 0.6%(D), 0.5%(V), 0.4%( ), and 0.1 %(0)- (From Bus-call et al. 1993, with permission from the Journal of Rheology.)...

Figure 8.8 Relative viscosity t]/t s versus Mason number for an ER fluid consisting of hydrated lithium poly(methacrylate) particles in a chlorinated hydrocarbon studied by Marshall et al. (1989) with = 0.23 at various field strengths, compared to predictions of two-dimensional Stokesian dynamics simulations (closed symbols) with and without near-field (NF) interactions at areal fraction = 0.4. Since p in the above was taken from the polarization model with Eq. (8-2), while the experiments were carried out under dc fields for which the effective polarization should be controlled by conduc-tivities [Eq. (8-2a)], the quantitative agreement between simulations and experiment is presumably...

Figure 13.18. Comparison between model and measurements for clays dispersed in polymers. Viscosities observed as a function of shear rate by Krishnamoorti et al [46] for dispersions of silicate platelets (weight fractions of 0.06 and 0.13) in poly(dimethyl siloxane) at T=301K are indicated with symbols. Calculated results, assuming platelets to be monodisperse flexible cylinders with aspect ratio Af=(thickness/diameter)=0.01, are indicated as lines, (a) Relative viscosity=r)(dispersion)/r (polymer). (b) Dispersion viscosity, r)(dispersion).

Figure 14 shows the variation of the steady shear relative viscosity at the high shear limit with the effective volume fraction as defined by equation 46 for poly(methyl methacrylate) (PMMA) suspensions of different sizes in decalin sterically stabilized by means of grafted poly (12-hydroxy stearic acid) chains with a degree of polymerization of 5. The stabilizing polymer layer thickness is 9 1 nm, in particular, A = 9 nm... 

Figure 16 shows the steady shear relative viscosity variation with the effective Peclet number, Peeg, based on the effective particle diameter at each temperature level, and the temperature for a PMMA suspension. The particles of 0.8 pm are sterically stabilized by a thick layer of terminally anchored poly(dimethylsiloxane) and suspended in n-hexadecane at the volume fraction of 0 = 0.282. The data points are... 

Figure 5, Comparison of the dependence of the relative viscosity (T]rei) of saponified, linear poly(acrylamide-co acrylate). Pw is the degree of polymerization.

One often makes do with a viscosity measurement at a single concentration (usually 0.5%) to give what is called the inherent viscosity 17)0 = (lni7rei/c)c for this concentration. Fikentscher constants K are also used, particularly in the German literature, to characterize the classic polymers such as poly (styrene) and poly (vinyl chloride). [The K here is not to be confused with the K, defined by Equation (9-151), of the modified Staudinger equation.] K is evaluated from the relative viscosity at relatively high concentrations from tabular data and the equation... 

Figure 5.1 Kinetic curves of the yield of caprolactam in the thermal degradation of poly caproamide of different initial relative viscosity 1 0.786, 2 0.612, 3 0.450, 4 0.400. Source Author s own files...

Figure 2. Relative viscosity-concentration plots in toluene at 25 C for poly 06-methylstyrene (Mn 6,000) end -capped with ( ) Mg carboxylate, (A) Mg sulfonate and ( ) dimethyl benzyl ammonium chloride.

The relative viscosity-volume fraction curve for water-in-oil emulsions (42) is shown in Figure 12. Isoparaffinic oil (Isopar M) was used in this case and the emulsions were prepared using an A-B-A block copolymer of PHS-PEO-PHS (Arlacel P135, supplied by ICI PHS refers to poly-12-hydroxystearic acid and PEO refers to polyethylene oxide). 

Figure 4.41 The relative viscosity versus shear rate for suspensions containing 20 vol% Si02 particles. The suspensions prepared at pH = 3.7 (the isoelectric point of the Si02) and pH = 7.0 contained no poly(vinyl alcohol). All of the suspensions containing poly(vinyl alcohol) were prepared at pH = 3.7. (From Ref. 67.)...

Viscometric measurements have revealed a rapid increase in the relative viscosity at a critical surfactant concentration. However, the behaviour depends on the type of poly electrolyte used. As an illustration, Figure 2.20 shows the viscosity-SDS concentration curves for two types of cationic polyelectrolyte JR-400 (cationically modified cellulosic) and Reten (an acrylamide/(j5-methylacryloxytrimethyl)ammo-nium chloride copolymer, ex Hercules). 

Figure 4.7 Variation of relative viscosity with shear rate for 20 vol% silica suspensions prepared at pH = 3.7 with varying concentrations of poly(vinyl alcohol). The relative viscosity vs. shear rate plot for an electrostatically stabilized suspension (pH = 7.0) with no poly(vinyl alcohol) is also shown. (Reprinted from Ref. 19 with kind permission from The American Ceramic Society Inc., Westerville, Ohio, USA.)...

An example of polymer solutions is P(VDF/TrFE)/DMF solution [49] (Fig. 11). Poly(vinylidene-co-trifluoroethylene) (P(VDF/TrFE)) is known as a strong dielectric polymer. It possesses a permanent dipole moment in the main chain. The electric field frequency dependence of the relative viscosity was measured by a capillary rheometer. The result showed a positive ER effect at 10 Hz whereas it showed a negative ER effect at 1 kHz. 

Fig. 11 Applied field dependence of relative viscosity for strong dielectric poly(VDF-TrFE)/DMS (normalized by the viscosity under no electric fieid) [491.

Strauss and Williamst have studied coil dimensions of derivatives of poly(4-vinylpyridine) by light-scattering and viscosity measurements. The derivatives studied were poly(pyridinium) ions quaternized y% with n-dodecyl groups and (1 - y)% with ethyl groups. Experimental coil dimensions extrapolated to 0 conditions and expressed relative to the length of a freely rotating repeat unit are presented here for the molecules in two different environments ... 

Polymer Solvent. Sulfolane is a solvent for a variety of polymers, including polyacrylonitrile (PAN), poly(vinyhdene cyanide), poly(vinyl chloride) (PVC), poly(vinyl fluoride), and polysulfones (124—129). Sulfolane solutions of PAN, poly(vinyhdene cyanide), and PVC have been patented for fiber-spinning processes, in which the relatively low solution viscosity, good thermal stabiUty, and comparatively low solvent toxicity of sulfolane are advantageous. Powdered perfluorocarbon copolymers bearing sulfo or carboxy groups have been prepared by precipitation from sulfolane solution with toluene at temperatures below 300°C. Particle sizes of 0.5—100 p.m result. 

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