A Green Approach Toward Oleic- and Undecylenic Acid-Derived Polyurethanes

Naturally occurring oleic and undecylenic acids were used as raw materials for the synthesis of novel polyur- ethanes (PUs). The application of environmentally friendly thiol-ene additions to 10-undecenoate and oleate derivatives was studied with the goal of obtaining renewable diols. The resulting monomers were then polymerized with 4,4 0 -methyle- nebis (phenylisocyanate), in N,N-dimethylformamide solution using tin (II) 2-ethylhexanoate as catalyst, to produce the corre- sponding thermoplastic PUs (TPUs). Also, ultrasound irradia- tion has been tested to improve the synthesis of PU. Under these conditions, TPUs were obtained in high yields (80-99%) with weight-average molecular weights in the 36-83 kDa range. The chemical structures of PUs were assessed by FTIR and NMR spectroscopy. The thermal and mechanical properties of the syn- thesized TPUs have been studied and they showed a clear de- pendence on the structure of the parent diol. MTT test was carried out to asses the potential cytotoxicity of the prepared PUs, indicat- ing no cytotoxic response. V C 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 2407-2416, 2011