Ricinoleic half-esters

Another class of PSA-fatty acid-based copolymers has been synthesized from the ricinoleic acid and ricinoleic half-esters with maleic and succinic anhydride, poly(sebacic-co-ricinoleic acid maleate), poly(sebacic-co-ricinoleic acid succinate), and poly(sebacic-co-12-hydroxystearic acid succinate) (P(SA-RAM), P(SA-RAS), and P(SA-HSAS)) (Krasko et al., 2003 Teomim et al., 1999). These syntheses result in poly(anhydride-co-esters). 

Sulfated Natural Oils and Fats. Sulfated natural triglycerides were the first nonsoap commercial surfactants introduced in the middle of the nineteenth century. Since then sulfates of many vegetable, animal, and fish oils have been investigated (see also Fats AND FATTY oils). With its hydroxyl group and a double bond, ricinoleic acid (12-hydroxy-9,10-octadecenoic acid) is an oil constituent particularly suited for sulfation. Its sulfate is known as turkey-red oil. Oleic acid is also suited for sulfation. Esters of these acids can be sulfated with a minimum of hydrolysis of the glyceride group. Polyunsaturated acids, with several double bonds, lead to dark-colored sulfation products. The reaction with sulfuric acid proceeds through either the hydroxyl or the double bond. The sulfuric acid half ester thus formed is neutralized with caustic soda ... 

Enzymes can be used to selectively hydrolyze only one of two ester groups in a molecule. An esterase from Pseudomonas putida was used to hydrolyze dimethyl adipate to more that 99% half ester.198 Pig liver esterase was used to hydrolyze dialkyl phthalates to the monoesters in 84-93% yields in 1-13 h.199 A porcine pancreatic lipase was used to hydrolyze linear diol diacetates to the monoacetates in 79-95% yields.200 Esters have been prepared from 12-hydroxystearic acid and C8-C18 alcohols in 82-90% yields without esterification of the 12-hydroxy group, by using an immobilized lipase from Rhizomucor miehei.201 Ricinoleic acid, which differs only by having a cis 9 double bond, formed oligomers with an immobilized lipase from C. rugosa.202 These were much less colored than the ones made by the commercial process, which is done at 200 C. 

The condensation reaction of diacetyl mixed anhydrides of aromatic or aliphatic diacids is carried out in the temperature range 150—200°C. The synthesis of polyanhydride from RA half-esters with maleic and succinic anhydride has been reported (Teomim and Domb, 1999). Ricinoleic acid maleate (RAM) or ricinoleic acid succinate (RAS) diacid half esters were polymerised by melt condensation as shown in Scheme 5.3. 

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