Synthesis and characterization of poly(diallyldimethylammonium chloride) in a broad range of molecular weight

Poly(diallyldimethylammmonium chloride) samples were prepared in a wide range of molecular weight by radical polymerization at low degree of conversion to realize undisturbed molecular weight distributions. Determination of the molecular and thermodynamic parameters by viscometry, osmometry, light scattering, gel permeation chromatography (GPC) and analytical ultracentrifugation (AUC) give acceptable agreement. The high values of the second virial coefficient would result in a corresponding excluded volume. However, the dependencies of the radius of gyration and the second virial coefficient on molecular weight do not reflect the excluded volume effect. The discrepancy can be explained by a dominating Donnan contribution. Taking into account the polydispersities of the samples, a Kuhn segment length of 5 nm was determined for poly(diallyldimethylammonium chloride) in 0.5 M NaCl solutions. [η]-M relations were obtained for 1 M NaNO3, 1 M NaCl and 0.5 M NaCl solutions.