Epoxidation of methyl oleate and subsequent ring-opening catalyzed by lipase from Candida sp. 99-125†

A green method for chemo-enzymatic epoxidation of methyl oleate was developed, resulted in epoxidized methyl oleate. Subsequently, excessive hydrogen peroxide and extended reaction time led to polyols through ring-opening reaction catalyzed by immobilized lipase from Candida sp. 99-125. The corresponding reaction conditions were systematically investigated. High epoxy number was obtained at 70 °C for 5 h when 1.5 wt % immobilized lipase and 1.5 equivalent of hydrogen peroxide were used. Interestingly, no hydrolysis reaction of epoxidized methyl oleate was observed. Moreover, epoxidized methyl oleate generated shown good plasticizing effect on PVC resin. On the basis of epoxidation reaction, more hydrogen peroxide and extended reaction time were employed in the ring-opening reaction, resulting in more polyols. Polyurethane rigid foams with good thermal conductivity, dimensional stability and compress strength could be successfully prepared through the use of polyols acquired by ring-opening reaction of epoxidized soybean oil. In addition, the enzyme showed good reusability towards epoxidation and ring-opening reaction. Practical applications: Epoxidation of methyl oleate and subsequent ring-opening reaction catalyzed by immobilized lipase from Candida sp. 99-125 afforded epoxides and bio-based polyols, respectively. The epoxides could be widely used as stabilizers for plasticizers, ingredients of lubricants and the intermediates for surfactants. The bio-based polyols were the potential alternative petrochemicals in polyurethane industry. Furthermore, successful achievement of this study would provide a powerful technical support for the application of enzyme catalysis in organic synthesis.