Polystyrene in toluene

Zimmt has reported the intensity of scattered light at various angles of observation for polystyrene in toluene at a concentration of 2 X 10" ... 

H. Kim, T. Chang, J. M. Yohanan, L. Wang, H. Yu. Polymer diffusion in linear matrices Polystyrene in toluene. Macromolecules 19 2121-21AA, 1986. 

Fig. 111.—Experimental values of the interaction parameter %i plotted against the volume fraction of polymer. Data for polydi-methylsiloxane M =3850) in benzene, A (New-ingi6). polystyrene in methyl ethyl ketone, (Bawn et aV ) and polystyrene in toluene, O (Bawn et alP) are based on vapor pressure measurements. Those for rubber in benzene, T (Gee and Orr ) were obtained using vapor pressure measurements at higher concentrations and isothermal distillation equilibration with solutions of known activities in the dilute range.

Fig. 116.—w/c plotted against c for several fractions of polystyrene in toluene at 30°C. Molecular weights of the fractions are indicated by the numbers appearing with each curve. The osmotic pressure n is expressed n g./cm.2 (Results of Krigaum. )... 

Fig. 3. Specific states of solution of narrowly distributed polystyrene in toluene as a function of the molar mass and the polymer concentration [19,40]...

Fig. 6. Specific viscosity, r sp, as a function of the product c- [q] for narrowly distributed polystyrene in toluene (good solvent) (A) and frans-decalin (poor solvent) ( ) at 25 °C. Experimental data for the polystyrene/toluene system at 30 °C (taken from [65]) are represented by (O). 

Polymers in solution or as melts exhibit a shear rate dependent viscosity above a critical shear rate, ycrit. The region in which the viscosity is a decreasing function of shear rate is called the non-Newtonian or power-law region. As the concentration increases, for constant molar mass, the value of ycrit is shifted to lower shear rates. Below ycrit the solution viscosity is independent of shear rate and is called the zero-shear viscosity, q0. Flow curves (plots of log q vs. log y) for a very high molar mass polystyrene in toluene at various concentrations are presented in Fig. 9. The transition from the shear-rate independent to the shear-rate dependent viscosity occurs over a relatively small region due to the narrow molar mass distribution of the PS sample. 

For polystyrene in toluene (a=0.736) detailed theoretically and experimentally derived results are given below [ 19]. 

Fig. 14. Slope in the power-law region of the flow curve as a function of the overlap parameter for narrowly distributed polystyrene in toluene...

Fig. 15. Influence of molar mass and concentration on the slope of the flow curve for narrowly distributed polystyrene in toluene (n=f(c) for Mw=l-107g/mol n=f(Mw) for c= 0.06 g/ml)...

Fig. 19. Shear stress and first normal stress difference plotted as a function of shear rate for different molar masses, and b at different concentrations of polystyrene in toluene... 

Tab. 5.1 Flowtimesofl % solution of polystyrene in toluene (air saturated) vs insonation flow time (960 kHz, 6.8 Wcm ).

The ultrasonic degradation of polystyrene in toluene decreases with an increase in the reaction temperature (see Section 2.6.3). 

Whereas all workers agree that the extent of degradation is increased in the presence of gas, there is some dispute regarding the extent to which it takes place in vacuo. For example Weissler [22] (Fig. 5.17) and separately Prudhomme and Graber [19] (Tab. 5.6), investigating the degradation of polystyrene in toluene, failed to observe any appreciable degradation in the absence of gas. 

Tab. 5.5 Percentage ultrasonic degradation and final R.M.M. of polystyrene in toluene at various temperatures.

Figures 5.24, 5.25 and 5.26 also show that the limiting molar masses are lower the higher the intensity. Whilst Okuyama [50] and Thomas et al. [51] predicted, and several workers observed [52], that the limiting molar mass is invariant with intensity, most workers now agree that decreases with increase in ultrasonic intensity. Price [39] found that the results of the ultrasonic degradation of polystyrene in toluene fitted equation (Eq. 5.22).

Fig. 5.22. Effect of intensity on degradation of polystyrene in toluene initial R.M.M. = 300 000 irradiation time 90 min.

Melville and Murray have investigated the degradation of polystyrene in toluene, albeit in vacuo and at a slightly lower insonation frequency (213 kHz) and compared their results with those obtained by Schmid (300kHz) at 15 atm (Tab. 5.9). 

Fig. 5.28. Degradation of polystyrene in toluene at various applied pressures a 15 atm o 8 atm 0 atm.

Price et al. [56] have fitted their degradation data for polystyrene in toluene to Eq. 5.12 and have shown, over a limited sonication time interval, that the value of the limiting molar mass increased with increase in concentration. (Tab. 5.11). 

A similar marked tendency to form gels was observed for solutions of telechelic sulfonated polystyrenes in toluene. Again, it was not possible to dissolve the gel by dilution. In principle this could be achieved using a solvent in which the equilibrium of the association of the ionic groups is shifted towards the side of the unimers. Alternatively, the efficiency of the crosslinks can be diminished by addition of monofunctional material. The chains sulfonated only at one end would be incorporated into the micellar... 

Although the irradiation of 200 kGy decomposes about 80% of polystyrene in toluene by the dissociative electron attachment, the yield of the decomposition is only 20% for solid toluene. Because of its low efficiency of scission, the coupled polystyrene may not be a polymer suitable as a radiation resist. However, the present study has shown that a polymer that can be decomposed into two equivalent skeletons by ionizing radiation is possible to be... 

The osmotic pressure of polystyrene (PS) solutions in toluene and methylethyl ketone (MEK) was measured at 25°C, and the results were analyzed to give B values of 4.59 x 10 4 and 1.39 x 10 4 cm3 g 2 mole, respectively, for the two solutions. Use these results to criticize or defend the following proposition According to Table 3.1, VCED = 8.5-9.1 for polystyrene. For toluene and MEK, VCED equals 8.9 and 9.04, respectively. Since the MEK solution has a smaller B value than the toluene solution, it appears that the best value to use for the VCED for polystyrene is at the upper end of the range of values given and close to the value of MEK. In this way the quantity [(VCED)MtK - (VCED)PS]2 will be smaller than the same quantity for polystyrene in toluene. This is consistent with the order of the B values. 

Kotaka,T., Kurata.M., Tamura,M. Non-Newtonian flow and normal stress phenomena in solutions of polystyrene in toluene. Rheol. Acta 2,179-186 (1962). 

Fig. 34. Flow curve of narrowly distributed polystyrene in toluene (Mw = 23.6 106 g/mol, c = 0.1 g/ ml). Arrow indicates critical shear at which shear-induced degradation occurs...

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