Synthesis and Characterization of Magnetic Poly(STY-EGDMA) Particles for Application as Biocatalyst Support in Octyl Oleate Ester Synthesis: Kinetic and Thermodynamic Parameters and Mathematical Modeling

Author(s)

Rangel, Amanda B. S. ; Silva, Mateus V. C. ; de Assis, Gabrielle P. P. ; Rosa, Cintia M. R. ; dos Santos, Julio C. ; de Freitas, Larissa

• Document type: Journal article
• Source: CATALYSIS LETTERS; v. N/A, p. 13-pg., 2022-12-08.

Abstract

This study aimed to (i) synthesize and characterize magnetic poly(styrene-co-ethylene glycol dimethacrylate) particles (STY-EGDMA-M) as immobilization support for Candida antarctica lipase B (CALB), (ii) determine kinetic and thermodynamic parameters of the immobilized biocatalyst in emollient ester synthesis, and (iii) develop a mathematical model for the bioprocess. The enzyme support was characterized by optical microscopy, hysteresis analysis, Fourier-transform infrared spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. Magnetic copolymer particles were found to have spherical shape, ideal for use as immobilization support. The results confirmed that magnetic particles were incorporated into the polymer matrix, whose saturation magnetization was about 7 emu g(-1) Immobilized CALB showed an activity of 570 +/- 48 U g(-1) in the hydrolysis of butyl butyrate. The derivative was used to synthesize octyl oleate by esterification of oleic acid with octanol. The influence of temperature on the esterification reaction was analyzed, and a mathematical model was developed to determine apparent kinetic and thermodynamic parameters. The highest ester conversion (56%) was obtained at 55 degrees C, and chemical equilibrium was achieved in 12 h of reaction. Under these conditions, the reaction was spontaneous, with negative Gibbs energy (-4.73 kJ mol(-1) K-1), positive entropy (+ 0.463 kJ mol(-1) K-1), endothermic nature (+147.53 kJ mol(-1)), and low activation energy (61.71 kJ mol(-1)). A second-order reversible kinetic model provided a satisfactory fit to the data (R-2 = 0.9965), within the 95% confidence interval. In an operational stability test, conducted for five consecutive cycles of 24 h, the biocatalyst had a half-life of 315.07 h. [GRAPHICS] . (AU)

• FAPESP's process: 16/10636-8 - From the cell factory to the Biodiesel-Bioethanol integrated biorefinery: a systems approach applied to complex problems in micro and macroscales
• Grantee: Roberto de Campos Giordano
• Support Opportunities: Program for Research on Bioenergy (BIOEN) - Thematic Grants
• FAPESP's process: 16/17833-3 - Emollient esters synthesis catalyzed by immobilized lipase on styrene-based polymers with magnetic properties
• Grantee: Larissa de Freitas
• Support Opportunities: Regular Research Grants