Selective formation of C36-dimer fatty acids via thiol-ene addition for copolyamide synthesis

Dimer fatty acids demonstrate interesting raw materials for the synthesis of polyamides and polyurethanes. The industrially well-established procedure of dimerizing poly unsaturated fatty acids yields a mixture of monomer, dimer and trimer structures, requiring the isolation of the pure dimer fatty acid. Within this study, the selective synthesis of C-36-dimer fatty acids derived from oleic acid is shown by simple thiol-ene addition of ethane-1,2-dithiol. Subsequently, the dimer fatty acid is used as comonomer for copolyamide synthesis in different ratios with hexamethylenediamine and dimethyl adipate. Experiments of water uptake and release are presented for these copolyamides showing improved properties compared to conventional polyamides.