Glycidyl‐terminated polyurethane modified epoxy resins: Mechanical properties, adhesion properties, and morphology

Glycidol was used to convert the isocyanate‐terminated polyurethane prepolymer to glycidyl‐terminated polyurethane prepolymer. The modified polyurethane not only offers some distinct advantages over the commercial polyurethane prepolymer, but also enhances the properties of the epoxy resins. The glycidyl‐terminated polyurethane modified epoxy resin proved to be superior to conventional epoxy resins in improving impact strength, fracture energy, and adhesion properties. The compatibility of the compounds in this glycidyl‐terminated PU/epoxy system was investigated using different preparation procedures. It was found that the synthesized glycidyl‐terminated polyurethane prereacted with curing agents, exhibited a lesser degree of phase separation, and can influence the mechanical properties of polymer blends. The results coincide with the phenomena observed in dynamic mechanical analysis and scanning election microscopy.