Oleochemical products as building blocks for polymers

The use of oleochemical derivatives is dominated by applications in the field of surfactants and emulsifiers. There also is a remarkable amount of highly specialised uses, for example in lubricants and as additives to modify the characteristics of polymers. Besides this, some products have been developed on the basis of oleochemical building blocks in the polymer backbone. Starting with oleic acid, the difunctional azelaic acid (C-9) is produced by ozonolysis for application in high-value polyesters and polyamides. Pyrolysis of castor oil or ricinoleic acid is the commercial route to sebacic acid (C-10). Castor oil itself is used as a polyol for the production of polyurethanes. Similar polyols with modified viscosity and application characteristics are made by epoxidation and ring-opening reactions of unsaturated fatty acid derivatives. Dimer acid (C-36) is obtained by a double bond reaction of C18 unsaturated fatty acids. By using hydrogenation technology, which is wellknown in the oleochemical industry to produce fatty alcohols, dimerdiols can be prepared from dimer acid. This dimerdiol is of great interest in polyurethane application fields in general, because it is a liquid, hydrophobic, long-chain raw material with two primary hydroxyl groups. By condensation of dimerdiol to building blocks with a molecular weight around 2,000 it is possible to prepare soft segments, that allow the production of thermoplastic polyurethanes (TPU) with modified application characteristics. Two different soft segments based on dimerdiol, ethers, and carbonates are discussed. The advantages for TPUs prepared from these building blocks are hydrolytic and oxidative stability and resistance to saponification and polar solvents.