Polyesters ofω-Unsaturated Fatty Acid Derivatives

Abstract

Unsaturated polyesters, based on ω-unsaturated fatty acid esters from oleochemical resources and petrochemical diols, were synthesized via two different synthetic pathways. 9-decenoic and 10-undecenoic acid methyl ester I a, b were transesterified with petrochemical diols to produce the α,ω-alkylene di(un)decenoates II a–d, which were subsequently converted into unsaturated polyesters by acyclic diene metathesis polymerization. A screening of ten homogeneous and heterogeneous metathesis catalysts was performed, implying optimum results for B2O3—Re2O7/Al2O3—SiO2 + SnBu4. Molecular weights (M̄w) up to 100 000 g/mol were determined by MALLS-GPC. On the other hand, C10 , C11 and C14-ω-unsaturated fatty acid methyl esters Ia–c were metathetically dimerized using homogeneous ruthenium and tungsten carbene complexes at an extremely low catalyst concentration. The resulting symmetrical, internally unsaturated, dicarboxylic acid dimethyl esters IIIa–c were polycondensated in bulk with conventional transesterification catalysts achieving molecular weights (M̄w) up to 110 000 g/mol. Melting temperatures of 6 to 92°C were determined by DSC.