Kinetic Studies on Oxirane Cleavage of Epoxidized Soybean Oil by Methanol and Characterization of Polyols

• Published in: Journal of the American Oil Chemists' Society Vol. 85; no. 2; pp. 113 - 117
• Main Authors: Lin, Bo, Yang, Liting, Dai, Honghai, Yi, Aihua
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Berlin/Heidelberg : Springer-Verlag 01.02.2008; Springer-Verlag; Springer; Springer Nature B.V
• Subjects: Agriculture; Biological and medical sciences; Biomaterials; Biotechnology; Bond strength; Chemical analysis; Chemicals; Chemistry; Chemistry and Materials Science; Dielectric properties; Differential scanning calorimetry; epoxides; Epoxidized soybean oil; ethylene oxide; Fat industries; Food additives; Food industries; Food Science; Fourier transform infrared spectroscopy; Fourier transforms; Fundamental and applied biological sciences. Psychology; General aspects; Hydrochloric acid; Hydroxylation; Industrial Chemistry/Chemical Engineering; Infrared spectroscopy; Kinetics; Low temperature; mathematical models; Methanol; molecular models; Original Paper; Polyol; polyols; Renewable resources; Ring opening; Soybean oil; Soybeans; Sulfuric acid; thermal properties; Thin films; Vegetable oils; Kinetics; Polyol; Hydroxylation; Epoxidized soybean oil; Ring opening; Kinetics, Polyol; Vegetable oil; Food additive; Edible oil; Characterization; Oils and fats industry; Sweetener; Epoxidized soybean oil, Ring opening; Soybean oil; Methanol
• ISSN: 0003-021X; 1558-9331
• DOI: 10.1007/s11746-007-1187-5

The kinetics of the oxirane cleavage of epoxidized soybean oil (ESO) by methanol (Me) without a catalyst was studied at 50, 60, 65, 70 °C. The rate of oxirane ring opening is given by k[Ep][Me]², where [Ep] and [Me] are the concentrations of oxiranes in ESO and methanol, respectively and k is a rate constant. From the temperature dependence of the kinetics thermodynamic parameters such as enthalpy (ΔH), entropy (ΔS), free energy of activation (ΔF) and activation energy (ΔE a) were found to be 76.08 (±1.06) kJ mol-¹, -118.42 (±3.12) J mol-¹ k-¹, 111.39 (±2.86) kJ mol-¹, and 78.56 (±1.63) kJ mol-¹, respectively. The methoxylated polyols formed from the oxirane cleavage reaction , were liquid at room temperature and had three low temperature melting peaks. The results of chemical analysis via titration for residual oxiranes in the reaction system showed good agreement with IR spectroscopy especially the disappearance of epoxy groups at 825, 843 cm-¹ and the emergence of hydroxy groups at the OH characteristic absorption peak from 3,100 to 3,800 cm-¹.