Numerical simulation of polymerization processes of diisocyanates and diols
Polimery 2000, No 3, 161
SummaryAn experimentally verified kinetic model of stepwise polyaddition , involving a series of consecutive and parallel reactions, was used to simulate the reaction of diisocyanates with diols to yield linear polyurethanes. The underlying assumptions and the method to derive model equations are given; the technological interpretation of model parameters is described. Variation ranges of model parameters are given in relation to polymerization conditions (time, temperature, reactants mole ratio, substitution effects in diisocyanates). Oligomer fraction concentrations, functional group conversion degrees, and average Μ of polyurethanes at successive process stages were calculated by well-known numerical procedures. When suitably rearranged, the relationship obtained allows to see the effect of process conditions and monomer structure on the properties of polyurethanes in relation to the preparation method used. Author's own routine, Reaktor, run in Windows 95, saves the results as ASCII files which can be retrieved into other software (Excel, Origin) and further processed to yield 2-D or 3-D graphs. Simulation results are at any moment available as 2-D diagrams with reaction time as the independent variable.