Monomers from vegetable oil feedstock: kinetics, catalysis and thermal risk

Wander Perez Sena*

*Tämän työn vastaava kirjoittaja

Tutkimustuotos: VäitöskirjatyypitTohtorinväitöskirjaArtikkelikokoelma

Abstrakti

Polyurethanes are among the most important polymers in our everyday life, they are industrially produced via the reaction of polyols and di-isocyanates. This process present multiple severe drawbacks such as high toxicity of the di-isocyanates. Furthermore, di-isocyanates are produced from petroleum-derived compounds such as phosgene, which is known to be an extremely toxic compound. In recent decades, a more environmental friendly strategy for the production of this precious polymer has emerged, that is the polymerization reaction of polycarbonates and polyamines, which takes the advantages of bio-based and carbon dioxide feedstock.

This scientific effort is devoted to the study of the reaction pathway for the production of polyurethanes from vegetable oils based raw materials. Vegetable oils are a green source of raw materials that offer several benefits such as non-toxicity, renewable character and biodegradable products.

Each reaction step required to upgrade vegetable oils to polyurethanes was investigated separately. The epoxidation reaction was first investigated from a process safety point of view. Different epoxidation methods were compared and it was found that direct epoxidation with hydrogen peroxide in the presence of a metal oxide catalyst such as aluminium oxide gives the lowest probability of thermal runaway. Thereafter, the kinetics of the system was investigated and its efficiency was enhanced by application of semi-batch reactor technology. Mathematical modelling of the reaction system was performed, and a rather good description of the experimental data was achieved.

A series of heterogeneous catalysts were synthetized and tested in the carbonation process of epoxidized vegetable oils. The most important parameter to obtain a good reactant conversion and product yield was the utilization of mesoporous materials as supports and the presence of a Lewis acidity source such as a metal.

A Tian-Calvet isothermal calorimeter was used to determine the reaction enthalpies of the aminolysis system. The reaction enthalpies of aminolysis and amidation were determined, denoting a low exothermicity. Thereafter, the kinetics of the aminolysis system was explored using four amines; mathematical models for each amine system were developed, and a linear free energy relationship (LFER) was established linking the substituent of the amine and the estimated reaction rate.
AlkuperäiskieliEnglanti
JulkaisupaikkaÅbo
Painoksen ISBN978-952-12-4067-6
Sähköinen ISBN978-952-12-4068-3
TilaJulkaistu - 2021
OKM-julkaisutyyppiG5 Tohtorinväitöskirja (artikkeli)

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