Intermolecular interactions and self-assembling of polyurethane with poly(vinyl alcohol) in aqueous solutions

The paper discusses the viscometric behaviour of aqueous solutions of polyurethane (PU), poly(vinyl alcohol) (PVA), and their mixtures of different compositions at 37 °C. Two models were used to determine the intrinsic viscosity and viscometric interaction parameters: the classical Huggins equation and the new Wolf approach. The higher hydrodynamic volume of PVA/PU mixtures as compared with the individual macromolecules can be explained by the new thermodynamic approache. The viscometric data were used to evaluate different miscibility parameters which are discussed as a function of PVA/PU mixture composition. The different types of interactions occurring in solution contribute to the miscibility of the two polymers and the preferential PVA-PU intermolecular interactions are responsible for the self-assembling phenomena. The thermodynamic conditions are favorable for the formation of the mixed coils containing PVA macromolecules and PU micelles.