Synthesis of Sucrose–Coconut Fatty Acids Esters: Reaction Kinetics and Rheological Analysis

The present study portrays the investigations on the optimization of the K2CO3-catalyzed synthesis of sucrose–coconut fatty acids esters. Determination of the hydroxyl value (HV) and the saponification value (SV), as well as Fourier transform infrared (FTIR) analysis, provided an understanding of the progress of transesterification, as a function of temperature (120–140 °C), holding period (30–150 min), catalyst concentration (1%–4%), molar ratio of sucrose to fatty acid methyl esters (FAME) (M = 0.364–6), and molecular weight of fatty acids. Bimolecular second-order kinetic model based on equal transesterification opportunity for all hydroxyl groups of sucrose/partial esters and that based on preferential transesterification of 6 −OH of the glucose unit in constant volume batch reactor were developed using integral and differential methods. The dependence of selective and nonselective kinetic models on the number and nature of hydroxyl groups in the sucrose were investigated. The changes in viscosity of sucrose ester solutions in dimethyl formamide (DMF) solvent were interpreted on the basis of solvent–ester/ester–ester interactions, hydrogen-bond density, and formation of mixed partial esters.