Abstract:Hydroxyl-terminated waterborne polyurethane (WPU) emulsions with different R values(-NCO/-OH) were synthesized firstly via acetone method, in which isophorone diisocyanate and poly (ε-caprolactone) di-OH are the main raw materials, with dihydroxy methyl butyric acid as hydrophilic monomer, triethylamine, 1, 4-butanediol, trimethylolpropane and organic silicon crosslinker as neutralizing agent, small molecule chain extender, inner-crosslinking agent and outer-crosslinking agent respectively. Then, two-component hydroxyl-terminated WPU adhesives with excellent properties were prepared by adding the 2% enclosed water-based isocyanate curing agents. The chemical structure, morphology and rheological properties of the adhesives were characterized by infrared spectroscopy, nuclear magnetic resonance, laser particle size analyzer, transmission electron microscopy and rheometer, seperately. Furthermore, the thermal and mechanical properties of the film were characterized via thermo-gravimetric analyzer and universal tensile testing machine. The results showed that comprehensive properties of adhesive prepared were best when R value is 0.85, the water absorption, tensile strength, elongation at break and peel strength of film is 19%, 14.74 Mpa, 236.53% and 0.421 KN/m, respectively.