VISCOSITY OF VINYL AROMATIC POLYMER SOLUTIONS

Viscosity data are presented for benzene solutions of three vinyl aromatic polymers: poly(1-vinylnaphthalene), poly(2-vinylnaphthalene) and poly(vinylbiphenyl) at 30°C and in the range of concentration c ≤ 4 [η]. The results are compared with those for polystyrene in a theta and a good solvent. The applicability of the superposition scheme developed earlier and the molecular weight dependence of the reducing parameters are examined. For reduced viscosities ̃gh ≡ ηsp c[η] below about 1·6, superposition is achieved for all molecular weights. Observed differences in the molecular weight range of validity of superposition at elevated concentrations for the systems considered can be correlated with chain stiffness and solvent-polymer interactions, as characterized by the parameter B. A new reduced variable c̃1 is suggested for a comparison of the relative positions of the generalized viscosity functions, ̃gh=f ( c ̃1), of different polymer solutions. The relative positions of the curves appear to be related to the relative values of the long range interaction parameter B. © 1969.