Synthesis and characterization of cationic waterborne polyurethane elastomer using poly(tetrahydrofuran-co-epichlorohydrin)

Abstract

Waterborne polyurethane (WPU) resins have gained significant interest across various fields of industrial applications due to their unique features such as better adhesion to all types of substrates, lower emission of volatile organic compounds (VOC) and less environmental problems than solvent-based products. A cationic waterborne polyurethane elastomer based on poly(tetrahydrofuran-co-epichlorohydrine) (poly(THF-co-ECH)) has been synthesized with excellent mechanical, thermal and film forming properties. The poly(THF-co-ECH) was prepared through cationic ring opening polymerization of tetrahydrofuran (THF) with epichlorohydrin (ECH) and an acid catalyst. The WPU was prepared through prepolymer technique by using N-methyl diethanolamine as a hydrophilic chain extender. The WPU synthesized with optimum composition formed a stable dispersion with average particle size of 105 nm. Fourier-transformed infrared (FT-IR) spectroscopy, thermal analyses, dynamic light scattering (DLS), scanning electron microscopy (SEM) and tensile test were utilized to characterize the structure and investigate the properties of the both dispersion and polyurethane casted film. The results revealed that the casted film of the prepared WPU has elastomeric properties and has the potential to be used for coating applications.