Synthesis and properties of water‐dispersible polyurethanes based on various diisocyanates and PEG as the hard segment

Abstract

AbstractWater‐dispersible polyurethanes are a greener alternative to polyurethane solutions in organic solvents. Various polyurethane materials were prepared by a two‐step polymerization procedure of polypropylene glycol with Mn of 2000, polyethylene glycol with Mn of 1500, and diisocyanates with different chemical structures, aliphatic, cycloaliphatic and aromatic. It was investigated how the diisocyanate structure affected the molecular morphology, contact angle measurements, and physical characteristics of water‐dispersible polyurethanes. FTIR and NMR measurements showed a close relationship between the intermolecular connections and the hard segment structure, mainly of the diisocyanate used. Also, the polarized light method showed that the presence of the PEG in the hard domain improved aggregation through physical interactions due to its structural flexibility and mobility. These water‐dispersible polyurethanes can assure the use of these polyurethane materials in a broad range of applications with increased environmental protection.