2010 Volume 37 Issue 5 Pages 223-230
Local motion of synthetic polymers and gellan in dilute solutions was examined by a fluorescence depolarization method. Rheological measurements were also carried out for gellan aqueous solutions. The mean rotational relaxation time, a measure of the local chain mobility, for polystyrene in a good solvent was shorter than that in a poor solvent at all the molecular weights of polystyrene examined including the oligomer region. It was suggested that the local chain mobility was mainly determined by the local potential energy for the conformational transition of main chain bond. The local chain mobility of gellan was independent of the added salt concentration (cs), whereas the cs dependence of zero-shear viscosity indicated that the degree of chain expansion of gellan decreased with increasing cs.
