Kinetics of glycerol and polyglycerol maleates production: Raw materials for partially bio-based concrete admixtures

In this work, the self-catalyzed kinetics to produce glycerol, diglycerol, and polyglycerol-4 maleate esters were experimentally determined from 60 oC to 80 degrees C. These esters can be used as intermediates in the production of partially bio-based admixtures that can replace petroleum-derived polycarboxylate ethers, which are traditionally used as concrete superplasticizers. The obtained experimental data were used to adjust the kinetic model parameters for the three reactions, including the effect of temperature. The model ade-quately predicted the behavior of the three proposed reactions, which was statistically validated using the Fisher-Snedecor test. The activation energies of glycerol, diglycerol, and polyglycerol-4 maleate were 29.5, 85.5, and 68.9 kJ/mol, respectively, with frequency constants of 7.93 x 102, 2.02 x 1011, and 4.48 x 108 min-1. The highest activation energy was obtained for the esterification of maleic anhydride (MAH) with diglycerol, indicating that this reaction is more temperature dependent. The kinetic constants at 70 degrees C were 2.56 x 10-2 min-1, 1.92 x 10-2 min-1, and 1.46 x 10-2 min-1 for the esterification of MAH with glycerol, diglycerol, and polyglycerol respectively, showing a greater reaction rate for the esterification with glycerol.(c) 2023 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.

Automated summary

In this study, the self-catalyzed kinetics for producing glycerol, diglycerol, and polyglycerol-4 maleate esters were experimentally determined across a temperature range of 60 oC to 80 degrees C. These esters are important intermediates for partially bio-based admixtures that can replace petroleum-derived polycarboxylate ethers in concrete superplasticizers. The experimental data were used to adjust the kinetic model parameters, including the temperature effect, and the model accurately predicted the behavior of the three reactions.