Synthesis and Properties of Caprolactam-blocked Non-ionic Waterborne Polyurethane Crosslinker

摘要

A novel kind of water-borne caprolactam-blocked non-ionic polyurethane crosslinker (CL-bnp) was prepared by prepolymer mixing process, using hexamethylene diisocyanate (HDI), poly(ethylene glycol) (PEG), 1, 1, 1-trimethylolpropane (TMP) and caprolactam (CL). The physical properties of prepared blocked polyurethane crosslinker dispersion, such as viscosity, pH and storage stability were measured. The chemical structure and its de-blocking temperature (Tde) were characterized by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimeter (DSC), and thermo-gravimetric analysis (TGA) techniques. The FTIR confirmed that the NCO groups of the original HDI molecule were completely blocked by this blocking agent. The thermal analysis measurements revealed that the maximum de-blocking ratio temperature of CL-bnp was around 160-170°C