Advanced Methods for Hydroxylation of Vegetable Oils, Unsaturated Fatty Acids and Their Alkyl Esters

Abstract

Vegetable oils and their derivatives have great potential as renewable and sustainable raw materials for the production of polyurethanes and bio-based polyols. For industry an important process is their modification. Chemical reactions that are carried out on vegetable oils and their derivatives are: transesterification, auto-oxidation, hydrogenation, epoxidation, hydroxylation, acrylation, isocyanation and others. One of the modifications are reactions performed on double bonds and/or carbonyl moieties of plants oils and their derivatives. These reactions result in products that are actively used as binders in coating materials due to their unique structural properties. In this manuscript, we describe important technological methods for the introduction of hydroxyl groups: opening of oxirane rings by nucleophilic reagents such as: water, alcohols, glycols, amino alcohols, carboxylic acids; direct hydroxylation of unsaturated bonds with carboxylic peracids in combination with hydrolysis of carboxyl groups and hydration; hydroformylation of unsaturated bonds with subsequent hydrogenation and alkoxylation; and ozonolysis of unsaturated bonds in combination with subsequent hydrogenation and alkoxylation.

Synthesis of TMP esters as a biolubricant from canola oil via a two‐step transesterification–transesterification process

“…[ 16 ] In addition, the final physicochemical properties of a lubricant depend on the type of polyol used, the aliphatic fatty acid chain length, and the number and position of unsaturated bonds in the fatty acid chain. [ 17 ] It should be noted that saturated FAs have a remarkably higher melting point than unsaturated ones and, in a mixture, they will crystallize at a higher temperature. [ 18 ]…”

“…[16] In addition, the final physicochemical properties of a lubricant depend on the type of polyol used, the aliphatic fatty acid chain length, and the number and position of unsaturated bonds in the fatty acid chain. [17] It should be noted that saturated FAs have a remarkably higher melting point than unsaturated ones and, in a mixture, they will crystallize at a higher temperature. [18] Significant research has been performed on the exploration of new modification methods and the development of more efficient catalysts for the modification and conversion of vegetable oils into esters and complex esters.…”

Biobased Semi-Interpenetrating Polymer Networks of Poly(ε-caprolactone) and Epoxidized Soybean Oil with Nanoscale Morphology, Shape-Memory Effect, and Biocompatibility

“…Plant oils are readily available and cost-effective materials in a large volume. − The chemical structures of all plant oils contain triglycerides of fatty acids of different degrees of unsaturation (i.e., the number of carbon–carbon double bonds). Plant oils can be chemically modified and functionalized into different reactive functional groups, such as hydroxyl, carboxylic acid, epoxy, amines, etc., to increase their utilization in making sustainable products. − Based on the different chemical modifications and functionalizations, plant oils can be used to synthesize many biobased polymers including polyesters, polyurethanes, and polyamides. − …”

Natural Oil Polyol from High-Oleic Palm Oil─Reaction Kinetics and Monitoring Using Near-Infrared Spectroscopy

“…Despite there are naturally occurring polyhydroxylated vegetable oils ( i.e. , castor oil), most commercial NOPs are synthetically produced from highly unsaturated vegetable oils such as soybean, rapeseed, and sunflower. ,, As observed in Figure , this is mainly performed via a two-step process through epoxidation and subsequent ring opening hydroxylation with a proton donor. In the first step, epoxidation is generally carried out with H 2 O 2 via the Prileschajew reaction using a percarboxylic acid intermediate. , Then, refined epoxidized oil can be subjected to controlled oxirane ring opening with different hydroxylation agents such as alcohols ( e.g.…”