Vegetable oils as platform chemicals for polymer synthesis

Natural vegetable oils have been transformed in polymers following three main routes. The first is the direct polymerization through the double bonds of the fatty acid chain. The cationic copolymerization of soybean oil with styrene, divinylbenzene, and different amounts of styrenic monomers containing Si allows producing materials with improved mechanical and flame retardant properties. The second route is the functionalization of the triglyceride double bonds to introduce readily polymerizable groups: The singlet oxygen photoperoxidation-dehydration of the allylic positions of the high oleic sunflower oil allows producing enone-containing triglycerides that are chemically crosslinked with aromatic diamines through aza-Michael reactions. At high temperatures, this curing reaction proceeds through a complex mechanism leading to quinoline moieties. This new crosslinking approach can be also applied to aldehyde containing triglycerides. The third route consists of using plant oil-derived chemicals like 10-undecenoic acid to produce tailor made monomers. Acyclic diene metathesis polymerization has been applied to allyl 10-undecenoate, 10-[2',5'-bis(10-undecenoyloxy)phenyl]-9,10-dihydro-9-oxa-10-phospha-phenanthrene-10-oxide, and 1,3-bis(10-undecenoyl) glycerol to prepare a set of polyesters with different phosphorus and hydroxyl contents. Moreover thiol-ene "click'' coupling of allyl 10-undecenoate with mercaptoethanol, 3-mercaptopropanoic acid, and 3-mercaptopropyl-trimethoxysilane has been used to produce difunctional telechelic polyesters.