A STUDY ON THE REACTIVE EXTRUSION PROCESS OF POLYURETHANE

An engineering analysis of the reactive extrusion process of a thermoplastic polyurethane was made through numerical simulation and actual experiment. The reactants used in this system were 4,4 prime diphenylmethane diisocyanate, polycaprolactone diol (M. W. , 824), and 1,4-butanediol with equivalent weight ratio of 2:1:1. As a catalyst, dibutyltin dilaurate was used. The reaction kinetics and the viscosity function were obtained through experiments, and the mathematical model which includes the conservation equations of mass, momentum, energy, and chemical species was solved numerically to obtain the velocity, concentration, temperature, viscosity, and pressure profiles. The actual experiments were performed in the laboratory scale extruder to compare the experimental results with those of the numerical simulation.