SynopsisData on the viscosity 7 of moderately concentrated solutions of polystyrene are reported. Several solvents were investigated, including cyclopentane solutions over a temperature span between 8 u = 19.5OC and 8 L = 154.5"C. The data were analyzed in terms of a relation giving 7 as a function of a$cpM, where a+, is the expansion factor for the chain dimensions in a solution with volume fraction cp of polymer with molecular weight M. It is shown that values of ap so determined decrease as d lna,/d lncp = (1 -2p)/6p for cp greater than cp* = 0.2M/s3 for moderately concentrated solutions, where s is the root-mean-square radius of gyration and p = b ln[q]/d 1nM with [7] the intrinsic viscosity.19.5-1545°C. This covers the interval between the upper and lower 8 temperatures 0" = 19.5"C and 0~ = 154.5"C, respectively, of polystyrene in cyclo-~e n t a n e .~,~ Data are also given for solutions in butanone, benzene, and cylohexane at selected temperatures. The molecular weight range of 3.6 X 104-2.11 X lo6 spanned by the data provides for results with cpM both smaller and larger than M , for polystyrene.Use of the polystyrene-cyclopentane system has several advantages for this study. Light-~cattering,~ vi~cosity,~ and phase equilibria5 with dilute solutions make available 8~ and 8 L , as well as the root-mean-square radius of gyration s , the second virial coefficient A2, and the intrinsic viscosity [r] as functions of T and M . Moreover, 8~ is low enough that polystyrene will not degrade if sealed in closed instruments, away from oxygen. The data on s and [r] show that these are equal at the temperatures 8~ and 8 L for which A2 is zero. For intermediate temperatures, A2 > 0 and s and [17] are functions of T , exhibiting maximum value

SynopsisFar-infrared spectra of a series of un-neutralized and neutralized lightly sulfonated polystyrenes with varying sulfonation levels have been investigated to seek spectroscopic evidence for microphase separation known to control the physical properties of these polymers. Broad, strong absorbance bands, not found in the spectrum of unmodified polystyrene, are o b s e~e d in the spectra of the sulfonated analogs. The effects on the far-infrared spectra both of sulfonation level and of the mass and charge of the neutralizing cation are discussed in terms of cation motion and the formation of ion-rich domains.

Integrated‐intensity light scattering data are reported for moderately concentrated solutions of polystyrene in benzene and in cyclopentane. The benzene system is one for which the second virial coefficient A2 is large; data obtained over the range 0.5 < A2Mc < 30, with c the polymer concentration, are analyzed in terms of the (extrapolated) intensity at zero angle and the angular dependence of the intensity. The former is discussed in terms of power law representations based on scaling relations, which are found to represent the data. The latter is discussed in terms of the dependence of the chain dimensions on concentration. With cyclopentane, the behavior is similar for temperatures for which A2 is near its maximum, but for T near either ΘU or ΘL, for which A2 is zero or small, the angular dependence of the scattering is distinctly different, with the intensity exhibiting a maximum as a function of scattering angle.

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