Polystyrene in benzene

The intrinsic viscosity of polystyrene in benzene at 25°C was measuredf for polymers with the following molecular weights ... 

Table 10.2 Values for Kcj/R at the Indicated Values of 9 and Cj for Solutions of Polystyrene in Benzene at 546 nm...

For a sample of polystyrene in benzene, experimental values of Kcj/R are entered in the body of Table 10.2. The values are placed at the intersection of rows and columns labeled c and 9, respectively. In the following example... 

Prepare a Zimm plot using the data in Table 10.2 and evaluate M, B,and for this solution of polystyrene in benzene. The effective wavelength in the medium is Xq/u = 546/1.501 = 364 nm for this experiment. 

Bywater 68) concerned with the polymerization of lithium polystyrene in benzene and published in 1960. 

To run the residence time distribution experiments under conditions which would simulate the conditions occurring during chemical reaction, solutions of 15 weight percent and 30 percent polystyrene in benzene as well as pure benzene were used as the fluid medium. The polystyrene used in the RTD experiment was prepared in a batch reactor and had a number average degree of polymerization of 320 and a polydispersity index, DI, of 1.17. 

In colloid science, colloidal systems are commonly classified as being lyophilic or lyophobic, based on the interaction between the dispersed phase and the dispersion medium. In lyophilic dispersions, there is a considerable affinity between the two constituent phases (e.g., hydrophilic polymers in water, polystyrene in benzene). The more restrictive terms hydrophilic and oleophilic can be used when the external phase is water and a nonpolar liquid, respectively. In contrast, in lyophobic systems there is little attraction between the two phases (e.g., aqueous dispersions of sulfur). If the dispersion medium is water, the term hydrophobic can be used. Resulting from the high affinity between the dispersed phase and the dispersion medium, lyophilic systems often form spontaneously and are considered as being thermodynamically stable. On the other hand, lyophobic systems generally do not form spontaneously and are intrinsically unstable. 

Fig Reduced and inherent viscosity-concentration curves for a polystyrene in benzene. 

The ultrasonic degradation of polystyrene in benzene increases with a decrease in the applied ultrasonic frequency (see Section 2.6.1). 

Tab. 5.7 Intrinsic viscosity vs irradiation time of polystyrene in benzene (1 %).

Melville investigated the effect of intensity, as measured by the anode current supplied to the oscillator, and observed that the degradation rate and extent of degradation for polystyrene in benzene increased with increase in intensity (Fig. 5.23). 

Fig. 5.23. Effect of intensity on the extent and rate of degradation of polystyrene in benzene.

Fig.2.14. Relation between viscosity and molecular weight for polystyrene in benzene at 20 °C...

Fig. 5.5. Ratio of Maxwell-constant to intrinsic viscosity as a function of molecular weight for oligomers of polystyrene in benzene at 20° C according to Tsvetkov Garmonova and Stankevich (166)...

In Fig. 5.5 the same type of plot is given for results which were obtained by the above mentioned authors 166) on solutions of oligomers of polystyrene in benzene at 20° C. The full curve is drawn according to eq. (5.24) with the parameters MA = 954 and (W/[ ])M = - 10-5 10 10 cm2/dyne. This value of MA corresponds to sB = 8.8. This value is rather satisfactory, when compared with literature values ( 8) (169). At the same time, the value of ratio (M/[f ])oo for infinitely high molecular weight is lower than Tsvetkov s value 12 10-10 cm2/dyne (166), as obtained in bromoform . In this connection, it should be admitted that the value obtained in bromoform is higher than in any other solvent. On the other hand, it remains clear that the fit of Fig. 5.5 is less satisfactory, perhaps due to a considerable polydispersity of the samples, as reported by the said authors. Very recently, Frisman, Sibileva and Chebishyan (170) reported a fair agreement between the results of the... 

Table 4. Dissociation and reactivity of lithium salt of living polystyrene in benzene-dimethoxy ethane mixtures at 25...

Hydrodynamic radii of poly(benzyl ether) dendrimers are shown in Fig. 5. Data for monodendrons with a hydroxyl focal group and tridendrons fall on the same curve. The value of the exponent v in Eq. (4) is 0.46 of low MW. At high MW it is 0.26 [48]. Data on low MW linear polystyrene in benzene [74] have been included in Fig. 5 for comparison. They highlight the little difference in the actual values of the hydrodynamic radii of linear polystyrene and low MW poly(benzyl ether) dendrimers. Deviations are observed only when MW>5xl03. Furthermore, the MW dependence of the radii of polystyrene and poly(benzyl ether) dendrimers are the same at low MW. This indicates that it remains impossible to draw major conclusions about the conformation of the low MW dendrimers from their global properties. The low values of the hydrodynamic radii of the high MW dendrimers, on the other hand, attest to their compact conformation. A similar transition to more compact dendrimers has recently been shown in a direct comparison of linear and dendritic poly(benzyl ethers) [75]. 

Busson and van Beylen [205] studied the role of the cation and of the carbanionic part of the active centre during anionic polymerization in non polar media. They were interested in the problem of complex formation between the cation and the monomer double bond [206] and they therefore measured the reaction of various 1,1-diphenylethylenes with Li+, K+ and Cs+ salts of living polystyrene in benzene and cyclohexane at 297 K. Diphenylethy-lene derivatives were selected for two reasons. 

Figure 26 Variations Ae in electric permittivity versus E for solutions of methyl polymethacrylate in benzene (O) (0.0973 g/100 cm ) and isotactic) polystyrene in benzene (A) (0.1104 g/100 cm ) measured by Przeniczny at a frequency of 6.5 MHz at 20 °C [Measurements by Gregson have not confirmed the magnitude of these Ae E) values (Senior Reporter) ...

Use the following table of data for KcjRo of a polystyrene in benzene at four concentrations and five angles, to construct a Zimm plot by plotting Kc/Rg against 100c + sin (0/2) with c in gmL and extrapolating to c- 0 and 0 0 to determine My, A2, and Rg. 

Dilution effect on the plateau modulus of linear polymers, Filled diamonds are polystyrene in cyclohexane at 34.5 °C (0-solvent), open squares are polystyrene in benzene at 25 °C (good solvent), filled circles are polybutadiene in dioctylphthalate at 25°C (near ... 

Hunston and Reischman showed that the contribution of 25 ppm of a 2 x 10 polystyrene in benzene solution to DR was negligible when added to 2.5 ppm of a 7 X 10 polystyrene (Fig. 3), demonstrating that a small amount of high-MW polymer dominates DR behavior in a mixture. ... 

Problem 4.12 Given below are typical light scattering data for solutions of polystyrene in benzene (fio = 1.5130) with A = 4360 A at 25°C ... 

Figure 4.13 Light-scattering determination of the molecular weight of polystyrene in benzene (Problem 4.12).

Problem 4.14 Measurements of excess scattering for a solution of polystyrene in benzene at 25 C with light of wavelength 4358 A yielded the following data... 

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