@article{BiermannMetzgerMeier2010, author = {Biermann, Ursula and Metzger, Juergen O. and Meier, Michael A. R.}, title = {Acyclic triene metathesis oligo- and polymerization of high oleic sun flower oil}, issn = {1022-1352}, doi = {10.1002/macp.200900615}, year = {2010}, abstract = {High oleic sunflower oil, a renewable raw material consisting of triglycerides with internal C=C-double bonds, was polymerized via acyclic triene metathesis (ATMET) to highly branched and functionalized polyesters. If the Hoveyda- Grubbs second generation catalyst was used and methyl acrylate was introduced as a chain stopper, 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 chain stopper. The resulting branched materials were characterized by GPC, H-1 and C-13 NMR, and ESI-MS.}, language = {en} } @article{BiermannMeierButteetal.2011, author = {Biermann, Ursula and Meier, Michael A. R. and Butte, Werner and Metzger, J{\"u}rgen O.}, title = {Cross-metathesis of unsaturated triglycerides with methyl acrylate synthesis of a dimeric metathesis product}, series = {European journal of lipid science and technology}, volume = {113}, journal = {European journal of lipid science and technology}, number = {1}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1438-7697}, doi = {10.1002/ejlt.201000109}, pages = {39 -- 45}, year = {2011}, abstract = {Highly functionalized dimeric triglycerides, such as compound 2, are obtained as minor products besides branched macromolecules from the acyclic triene metathesis (ATMET) polymerization of unsaturated triglycerides such as glyceryl triundec-10-enoate 1 and methyl acrylate (MA) in the presence of the second generation Hoveyda-Grubbs catalyst. The formed amount of interesting products of lower molecular weight during the ATMET reaction depends on the ratio of MA and triglyceride, reaction time, and temperature. We isolated the dimeric metathesis product 2 and synthesized the respective partially hydrogenated dimer 3 regioselectivly in a seven step reaction sequence starting from 10-undecenoic acid 7 and glycerol. Product 3 was unambiguously characterized by (13)C and (1)H NMR and MS as well as the further intermediate products of the seven step reaction including 10,11 bromo-undecanoic acid 8, the respective brominated 1,3-diglyceride 9, the brominated 1,3-triglyceride 6, and the self-metathesis products 4 and 5 which were isolated and purified.}, language = {en} }