Synthesis of 2-(methacryloyloxy)ethyl palmitate by transesterification of tripalmitin with HEMA

The vital issue regarding the preservation of natural resources has refurbished the interest in developing novel materials from the use of renewable sources, whose ubiquitous character offers civilization valuable elements of sustainability [1]. Vegetable oils, predominantly formed by mixed triglycerides with fatty acid moieties, have become an emergent field of research due to their remarkable potential as starting materials for the production of original polymers. However, the rather low reactivity of the saturated or unsaturated aliphatic chains of fatty acids makes them ineffective monomers for direct polymerization. This drawback can be overcome by functionalizing the fatty acids with polymerizable moieties. The transesterification with monohydric alcohols (mostly methanol) yields fatty acid alkyl esters, which are promising substitutes for diesel fuel [2,3], but which do acquire the monomer status because the transformation does not incorporate reactive functions.
The present communication reports the synthesis of a fatty acid-based monomer bearing acrylic moieties via the transesterification of tripalmitin with 2-hydroxyethyl methacrylate (HEMA). A systematic study was performed in order to optimize reaction conditions, yields and purity of the ensuing monomer. Results related to a preliminary investigation of its polymerization will also be reported.

References
[1] Belgacem, M.N.; Gandini, A. (Eds.) Monomers, polymers and composites from renewable resources. Amsterdam: Elsevier, 2008.
[2] Schuchardt, U.; Sercheli, R.; Vargas, R. M. J. Braz. Chem. Soc. 1998, 9, 199.
[3] Balat, M. Energ Source A 2009, 31, 1300.