earticle

영어

Lactide that have been used as monomer for ring-opening polymerization of PLA (poly lactic acid) is important material for industrial production of PLA which is one of bio-plastics. However, enantioselective reaction from lactate to lactide has been not reported so in this study lactide was enantioselectively synthesized by esterification of lactate using lipase. The one of many lipases which was CAL-B only could synthesize lactide as highest conversion and showed R-specific enantioselectivity.[1],[2] Although lactide and lactate have less solublility than other ether solvent[3],[4], hexane is used as an appropriate solvent for reaction due to showing the higher activity than any other solvents. Also when the reaction temperature is changed from 5℃ to 60℃, the rate of consumption and conversion is gradually increased. However, the final amount of lactide is still same after 24 hours in spite of increasing temperature. The result of 2nd reaction showed that reaction was limited by absorption ability of molecular sieve about alcohol. Therefore, if a process for the effective removal of alcohol were developed, Enantiospecific lactide is produced by CAL-B with more efficiency.