Exploring fatty acid derivatives from renewable resources as raw materials for coating applications

Abstract: In the work presented herein, epoxy fatty acid derivatives were explored in the formation of thermosets for coating applications. The epoxy fatty acid derivatives were obtained from renewable resources such as birch tree bark and epoxidized linseed oil. The birch bark was used to isolate 9,10-epoxy-18-hydroxyoctadecanoic acid (EFA) and the epoxidized linseed oil was used to retrieve methyl stearate and 3 different epoxy methyl esters: epoxy methyl oleate/linoleate/linolenate (EMO/EMLO/EMLEN). The obtained epoxy fatty acid derivatives were used in resin formulations together with other reactants or in the synthesis of multifunctional oligomer resins using enzyme catalysis. All resins were cured using different polymerization techniques to form thermosets with a wide variety of properties.Multifunctional oligomer resin were synthesized using Candida Antarctica lipase-B (CALB) as enzyme. It was demonstrated that the synthesis was efficient and the oligomers were obtained from “one-pot” route. In addition, the selectivity of CALB was useful in preserving a variety of functional groups (epoxides, alkenes and thiols) in the final oligomers. The oligomers were cross-linked by either thiol-ene chemistry or cationic polymerization resulting in functional thermosets. It was further shown that surface properties of the cured thermosets could be changed by using post-functionalization.Pure fatty acid methyl esters cure into soft materials. An approach in increasing the thermal and mechanical properties was investigated. The 3 different epoxy functional methyl esters together with a furan-2,5-dicarboxylic acid derivative were investigated in the formation of thermosets. Glass transition temperature (Tg) below 0 °C and above 100 °C were obtained by varying the stoichiometric feed of the reactants.The thermal curing of EFA as a one-component system was investigated by model studies showing that a self-catalyzed process occur. EFA thermally cures into a thermoset without the need of an added catalyst. Furthermore, the thermoset showed adhesive properties.Crude mixture containing methyl stearate, EMO, EMLO and EMLEN obtained from epoxidized linseed oil were investigated as reactive diluent in coil-coatings. The mixture was also compared with commercially available reactive diluents such as fatty acid methyl esters (FAME) obtained from rapeseed oil. The results obtained showed that more fatty methyl esters could be incorporated in the final thermoset when using the epoxidized linseed oil fatty acid derivatives.Real-time Fourier-transform infrared spectroscopy (RT-FTIR) was used during most of the work presented in the thesis and proved to be a powerful tool in monitoring the different reactions and comparing relative reaction rates.