PHYSICAL STUDIES OF IONICALLY-TERMINATED POLYTETRAHYDROFURAN .2. APPLICATION OF THE MARK-HOUWINK RELATION AND DETERMINATION OF UNPERTURBED MOLECULAR DIMENSIONS

Tetrahydrofuran polymers terminated at one end with a pyridinium bromi de group were prepared and their hydrodynamic behaviour contrasted wit h the equivalent methoxy-terminated polymers. The hydrodynamic behavio ur of methoxy-terminated polytetrahydrofuran in cyclohexane, toluene, tetrahydrofuran, methyl ethyl ketone and cyclohexanone and (pyridinium bromide)-termined polytetrahydrofuran in tetrahydrofuran, methyl ethy l ketone and cyclohexanone was consistent with that of partially free- draining random coils. In cyclohexane and toluene, the pyridinium brom ide-terminated polymers possess aggregated structures (multiplets). Th ese multiplets contain between 2 to 3 ionic chain ends.