Acyclic Triene Metathesis Oligo- and Polymerization of Oleochemicals

The synthesis of branched macromolecules from renewable raw materials via olefin metathesis should be of importance because the resulting polymers are expected to show interesting properties e.g. as base materials for coatings, additives or processing aids for linear thermoplastics. The acyclic diene metathesis (ADMET) polymerization is known to be a versatile technique for the preparation of linear polymers, polymers with a defined degree of branchings, telechelics as well as block-copolymers. The acyclic triene metathesis (ATMET) polymerization using glyceryl triundec-10-enoate as starting material has been described to give in a simple one pot one step procedure using different ratios of the triglyceride and methyl acrylate as chain stopper branched macromolecules of different molecular weights.[1] Recently we developed the ATMET polymerization of high oleic sunflower oil, a renewable raw material consisting of triglycerides with internal C=C-double bonds, to yield highly branched and functionalized polyesters.[2] If the Hoveyda-Grubbs second generation catalyst was used and methyl acrylate was introduced as a chainstopper, the molecular weight of the obtained polymers could be tuned by varying the ratio of the triglyceride and methyl acrylate. Using the first generation Grubbs catalyst for the polymerization of high oleic sunflower oil, no cross-linking was observed, even without the use of a chainstopper. The resulting branched materials were characterized by GPC, 1H and 13C NMR and ESI-MS.
First experiments showed that the branched polymers can be used in coating applications.

1 P. A. Fokou, M. A. R. Meier, Macromol. Rapid Commun. 2008, 29, 1620-1625.
2 U. Biermann, J. O. Metzger, M. A. R. Meier, Macromol. Chem. Phys. 2010, in press.