Rigid rod‐random coil transformation, Mark‐Houwink constants, and Millich's intrinsic isoviscosity, [η]_<i>M</i>, and isohydrodynamic volume, [η]_<i>M</i><i>M</i>_<i>M</i>

Abstract

Abstract On the basis of values of Mark–Houwink constants of rigid rod—polymer systems and their conformers a unique stage can be recognized which is common to all polymers of this type, independent of polymer conformation and solvent medium. The crude values derived for these polymer–solvent systems at 20–30°C. of Millich's intrinsic isoviscosity, [η] M , is 0.28 ± 0.04 dl/g, occurring at the coordinate molecular weight, M M , of 42,700, and produces a value of ca. 170 Å of Millich's isohydrodynamic polymer volume at this stage and temperature. Utility in the use of [η] M M M as a standard reference state, assuming reliable Mark–Houwink constants that obtain for strictly linear, monodisperse polymer samples, is indicated.