A high performance of catalyst material for delaying polyurethane (PU) polymerization at room temperature and rapid PU polymerization at preferred temperature still remains a great challenge because of adverse activation. Herein, N-heterocyclic carbene (NHC)-FeCl3 complex catalyst is developed and optimized to control the PU polymerization. The effects of PU polymerization degree and reaction kinetic is remarkably altered by the NHC-FeCl3 catalyst. It is found that the as-synthesized NHC-FeCl3 shows efficient catalytic activity as very low viscosity changes in room temperature and fast curing (3 h) at 60 degrees C, which proves considerable catalytic activity than the commercial catalyst and none-catalyst system. Based on DSC measurement, an increase in reaction rate is observed to PU polymerization with NHC-FeCl3. The PU polymerization reaction has excellently initiated at 60 degrees C by NHC-FeCl3 catalyst, where NHC act as Lewis acid and interacts with polyol, and FeCl3 reacts with isocyanate by electrophilic reaction. (C) 2019 Elsevier Inc. All rights reserved.