Analysis of hydrodynamic data on polymethacrylates with mesogenic pendant groups

Dilute solutions of poly{6-[4-(4-methoxyphenoxycarbonyl)phenoxy]hexyl methacrylate} (1 a, structure-based IUPAC name poly(1-{6-[4-(4-methoxyphenoxycarbonyl)phenoxy]hexyloxycarbonyl}-1-methylethylene)) were investigated by means of size-exclusion chromatography (SEC), osmometry, light scattering, and viscometry. It was found that the universal calibration of SEC is not valid with this polymer and that dilute solution properties (intrinsic viscosity, second virial coefficient) are at variance with predictions from the two-parameter theory of polymer solutions. The latter discordance is explained on the basis of the theory of hydrodynamic properties of wormlike chains which takes into account the effective diameter of the chain. The characteristic ratio (C ∞ = 15,1) and the Kuhn segment length (λ−1 = 28 · 10−8 cm) were estimated. The polymer-solvent interaction parameter was shown to decrease in the series of solvents: 1,1,2,2-tetrachloroethane, chloroform, tetrahydrofuran, N,N-dimethylformamide. The interaction of the solvents with the side groups was shown to be the determining factor.