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Catalytic Kinetics and Mechanism Transformation of Fe(acac) 3 on the Urethane Reaction of 1,2‐Propanediol with Phenyl Isocyanate
Author(s) -
Yang Pengfei,
Li Tianduo,
Li Junying
Publication year - 2013
Publication title -
international journal of chemical kinetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.341
H-Index - 68
eISSN - 1097-4601
pISSN - 0538-8066
DOI - 10.1002/kin.20798
Subject(s) - chemistry , catalysis , arrhenius equation , isocyanate , activation energy , kinetics , enthalpy , reaction mechanism , reaction rate constant , chemical kinetics , fourier transform infrared spectroscopy , order of reaction , standard enthalpy of reaction , reaction rate , associative substitution , entropy of activation , inorganic chemistry , thermodynamics , organic chemistry , chemical engineering , polyurethane , physics , quantum mechanics , engineering
The urethane reaction of 1,2‐propanediol with phenyl isocyanate was investigated with ferric acetylacetonate (Fe(acac) 3 ) as a catalyst. In situ Fourier transform infrared spectroscopy was used to monitor the reaction, and catalytic kinetics of Fe(acac) 3 was studied. The reaction rates of both hydroxyl groups were described with a second‐order equation, from which the influence of the Fe(acac) 3 concentration and reaction temperature was discussed. It was very surprising that the relationship between 1/ C and t became constant when reaction temperature increased, which indicated that there was no reactive distinction between the two hydroxyl groups. Although the phenomenon differed with the variation of temperature, it was unaffected by the Fe(acac) 3 concentration. It was attributed to the transformation of the reaction mechanism with the increase in temperature. Furthermore, activation energy ( E a ), enthalpy (Δ H* ), and entropy (Δ S* ) for the catalyzed reaction were determined from Arrhenius and Eyring equations, which testified to the transformation of the reaction mechanism.