Fatty acids, castor-oil, caustic-oxidized, distn. residues, esters with 1,3-butanediol are industrial derivatives obtained by first subjecting castor oil to caustic oxidation and distillation to produce a residue rich in fatty acids, primarily ricinoleic, oleic and linoleic acids. These fatty acids are then esterified with 1,3-butanediol to yield a mixture of mono-, di- and polyesters featuring hydroxylated fatty acid chains linked via butanediol spacers.
The discovery of such esters stems from the broader use of castor oil derivatives in materials and chemical industries as renewable and functional polyol feedstocks. The caustic oxidation step introduces carboxyl groups suitable for subsequent esterification, while 1,3-butanediol contributes a flexible diol backbone. This combination was developed to create bio-based intermediates for polymers, lubricants, surfactants and other functional materials, leveraging castor oil’s unique hydroxyl functionality.
Applications of these esters include their use as polyol components in polyurethanes and alkyd resins. The hydroxyl-functional fatty chains can react with isocyanates to form urethane linkages or with polyacids and anhydrides to form polyester and alkyd structures. Such bio-based polyols improve flexibility, adhesion and hydrophobicity in coatings and foams. They also serve as lubricity enhancers in metalworking fluids and surfactants in emulsions where the fatty ester structure aids interfacial activity.
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