Standard polystyrene solutions of known average molar masses continue to be used as for the calibration of many methods of characterizing polymer solutions. M. Kolinsky and J. Janca (J. Polym. Sci, Polym Chem 12, 1181 (1974)) studied polystyrene in tetrahydrofuran (THF) for use in calibrating a gel permeation chromatograph their results for the intrinsic viscosity, [η)], as a function of average molar mass at 25°C are given in the table below. (a) Obtain the Mark-Houwink constants that fit these data. (b) Compare your values to those in Table 19.4 and Example 19.5. How might you explain the differences?

Transcribed Image Text:

M,/(kg mol-) 5.0 10.3 19.85 51 In1/(cm'g) 98.2 173 411 867 27.6 43.6 67.0 125.0 206.7 14.0 5.2 8.8