Influence of the airflow and humidity on the chain aggregation during the film-formation in a flexible waterborne polyurethane formulation.

Statement Of Objectives: Soft, waterborne polyurethane dispersions are indispensable components in many state-of-the-art materials, with applications ranging from binders for coatings and adhesives to matrixes for flexible devices. While the static bulk nanostructure of such systems is widely studied, the influence that environmental conditions such as relative humidity and airflow have on their film formation and phase segregation behavior in supported films is unknown.

Experiments: Here, we elucidate the nanostructure evolution occurring during drying of an industrially relevant, soft polyurethane, utilizing real-time, non-destructive grazing incidence X-ray scattering analysis.

Co-assembly of precision polyurethane ionomers reveals role of and interplay between individual components.

Industrial and household products, such as paints, inks and cosmetics usually consist of mixtures of macromolecules that are disperse in composition, in size and in monomer sequence. Identifying structure-function relationships for these systems is complicated, as particular macromolecular components cannot be investigated individually. For this study, we have addressed this issue, and have synthesized a series of five sequence-defined polyurethanes (PUs): one neutral-hydrophobic, one single-charged hydrophilic, one single-charged hydrophobic and two double-charged amphiphilic PUs (one symmetric and one asymmetric).