Hydroxyl telechelic building blocks from fatty acid methyl esters for the synthesis of poly(ester/amide urethane)s with versatile properties

A series of bio-based diols containing ester, ester-amide and amide linkages were synthesized from methyl undecenoate (derived from ricin oil) and methyl oleate (derived from sunflower oil). These polymerization grade monomers were thoroughly characterized by FTIR-ATR, NMR spectroscopy and GC. A plethora of thermoplastic polyurethanes (TPUs) with tuned thermo-mechanical properties were prepared by combining the various diols and the diisocyanates, IPDI and MDI. The structural and thermo-mechanical characterizations of PUs were performed by means of FTIR-ATR, SEC, DSC, TGA, DMA, WAXS and tensile-test experiments. As expected, the PUs displayed amorphous to semi-crystalline features with respect to the nature of the diols and diisocyanates. Modulated DSC revealed glass transition temperatures in the range of -27 degrees C to 63 degrees C as well as melt crystallization of metastable phases upon heating. The incorporation of amide functions into the PUs enhanced the Young's modulus from 287 MPa to 775 MPa, while the elongation at break decreased from 269% to 41%. A complex degradation behavior of these PUs was observed by TGA above 280 degrees C.