Kinetic Studies of Isophorone Diisocyanate-Polyether Polymerization with in situ FT-IR.

Isophorone diisocyanate is used to react with poly (propylene oxide) of 1000 number average relative molecular mass in different temperatures. In situ FT-IR is used to monitor the reaction to work out rate constant, Arrhenius equation, and Eyring equation. The polymerization reaction has been found to be a second-order reaction, and rate constant seems different between the first stage and second stage at 5°∼10°C. However, it is surprising that the reactivity difference disappeared and the reaction rate merges when reaction temperature increases. The 1/(1 − p)∼t curves become straight at 15°∼25°C. Finally, the activation energy (E a), activation enthalpy (ΔH), and activation entropy (ΔS) for the polymerization are calculated, which are 73.9 KJ · mol−1, 71.6 KJ · mol−1, and −21.0 J · mol−1 · k−1, respectively. [ABSTRACT FROM AUTHOR]