Vegetable oils hydroformylation

The hydrogenation step following hydroformylation serves two important purposes. It reduces the aldehyde intermediate product to the desired primary alcohol functional group, which is the primary site of reactivity of the polyol with isocyanates. It also reduces the residual olefins in the FAMEs to saturated hydrocarbons, thus eliminating the pathway to Hock degradation and odor development, which is inherent to other processes that leave fatty acid unsaturation in the polyols. This step eliminates the typical vegetable oil odor from the final namral oil polyols of this process. 

Fig. 22 Respirometry of vegetable oil-based polyurethanes made from the following polyols triolein-met arrowhead), soy-HF (filled square), soy-met 180 (open diamond), soy-met 206 (open circle), and linseed met (open square). Also shown is ESO/BF3 polymer (open triangle) and soybean oil control (filled circle). Temperature was increased from 30°C to 55°C on day 71. Note that hydroxyl number of 180 has the functionality of 3.3 and that of hydroxyl 206 is 4.0. Met refers to polyol made from ESO and methanol HF refers to polyol from hydroformylation and reduced ESO. Reproduced from [152] by permission of Journal of Polymers and the Environment...

Petrovic ZS, Cvetkovic I, Hong DP, Wan X, Zhang W, Abraham TW, Malsam J (2009) Vegetable oil-based triols from hydroformylated fatty acids and polyurethane elastomers. Eur J Lipid Sci Technol 112 97-102. doi 10.1002/ejlt.200900087... 

The most abundant fatty acids in vegetable oils and fats are palmitic acid (hexa-decanoic acid or 16 0), oleic acid ([9Z]-octadec-9-enoic acid or 18 1 cis-9), and lino-leic acid (cis, cis-9,12-octadccadicnoic acid or 18 2 cis-9 cis-12) [21], Other fatty acids are found in special oils (e.g. 80% 87% ricinoleic acid in castor oil) [23], but these oils are quite rare. Castor oil, for example, has a production rate of 610,000 tons/year compared to the top four palm oil (46 million tons/year), soya oil (40 million tons/year), rapeseed oil (24 million tons/year), and sunflower oil (12 million tons/ year) [24]. Further sources of fatty acids are tall oils (2 million tons/year) [25] and to a lesser degree synthetic fatty acids derived by mainly hydroformylation and hy-drocarboxylation of olefins [23], The summed fatty acid production is estimated to be 8 million tons/year (2006) [23],... 

Hydroformylation is one of the most important chemical transformations of vegetable oils in polyols. The raw material used is not the relatively expensive epoxydised vegetable oil, but the cheap natural vegetable oil. 

Polyols obtained by the hydroformylation of vegetable oils have a primary hydroxyl group and one extra methylene group and are therefore more reactive than the secondary hydroxyl groups of epoxidized polyols. - Polyurethanes prepared in this way deliver high yields through utilisation of the polyols (Fig. 6.6). 

Epoxidised and hydroformylated vegetable oil-based polyurethanes leave parts of the chain dangling, which may affect the properties of the final product. However, dangling chains are not present in polyols made by ozonolysis and can therefore be used effectively in the synthesis of polyurethanes (Fig. 6.7) ... 

The analysis of reaction products can be rather tedious, especially when mixtures of vegetable oils are subjected to hydroformylation. Usually, NMR spectroscopy, GC/MS, and ICP-MS are utilized in an integrated approach. 

The hydroformylation of vegetable oils (soybean, high oleic safflower, safflower, and linseed) using Rh(CO)2(acac) as the catalyst precursor in the presence of PPhs or (PhOlsP was studied. The ligand (PhO)3P resulted in a lesser reactivity compared to TPP in contrast to the rates of bulky phosphite ligands reported in the literature [16]. 

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