DSC study of the polyurethane formation from poly(ethylene adipate) and toluene diisocyanate

摘要

AbstractThe reaction of poly(ethylen adipate) (PEA) and toluene diisocyanate (TDI) is studied by means of isothermal DSC. The reaction has the stoichiometry of PEA/TDI = 0.5 and a reaction enthalpy of ΔH= −65.0 kJ/mol hydroxyl group. The kinetic order is unity over a wide range of temperature and composition of the reaction mixture. The temperature dependence of the first‐order rate constant yields an apparent activation energy of 61.1 kJ/mol. The kinetic data are accommodated by the following rate law:documentclass{article}pagestyle{empty}begin{document}$$ {rm rate} = k_1 frac{{left {{rm PEA}} rightleft {{rm TDI}} right}}{{2left {{rm PEA}} right + left {{rm TDI}} right}} $$end{document}A mechanism involving a mobile preequilibrium to accommodate the experimental results is prop