Synthesis and characterization of waterborne polyurethanes based on isophorone diisocyanate and mixed Polyols of Poly(tetramethylene glycol)/Polydimethylsiloxane Diol

Abstract

Linear and cross-linked waterborne polyurethanes (WPUs) based on isophorone diisocyanate and mixed diols of poly(tetramethylene glycol)/hydroxyethyl- terminated polydimethylsiloxane (PDMS-OH) were synthesized with dimethylol propionic acid as an anionic component, trimethylolpropane as a cross-linking agent, and butanediol as a chain extender and characterized. The hydrophobicity, Tg, stress-strain behaviors of the linear or cross-linked siloxane-containing WPU (WPU-Si) films with different PDMS content were analyzed by using water contact shape analyzer, energy dispersive spectrometer, dynamic mechanical analyzer, and universal testing machine. The results reveal that as the PDMS content increased, the hydrophobicity of WPU-Si films increased, T g moved to higher temperature, the breaking stress increased, and the breaking strain decreased.