Synthesis and Characterization of Waterborne Polyurethane/Clay Nanocomposite – Effect on Adhesive Strength

Waterborne polyurethane (WBPU)/clay nanocomposites were synthesized using prepolymer process with different clay content (0–5 wt%) of organoclay cloisite 15A. The optimum dispersion temperature of clay in polyol was found to be 80 °C at 3 hours. The XRD confirmed the exfoliation dispersion of clay by polyol in WBPU/clay nanocomposite. IR and 1H‐NMR spectroscopy confirmed the unreacted condition of clay component. Particle size of the WBPU/clay nanocomposite dispersion was increased with increasing of clay concentration. Water swelling was decreased with increasing of clay up to the optimum content (2 wt %) and then leveled off. The thermal stability, mechanical property and adhesive strength were increased with increasing clay content up to 2 wt% to reach its maximum value.