| 초록 |
Poly(lactic acid) (PLA) is a well known biodegradable polymer that has found a number of applications in industry. It is difficult to obtain high molecular weight PLA using the direct condensation reaction. The most industrially acceptable process for the fabrication of synthetic PLA reported so far is via lactide formation. In this process, the lactic acid monomer is first polymerized to oligomeric PLA, then depolymerized to lactide, and finally re-polymerized to attain a high molecular weight by a ring opening mechanism. In this study, oligomeric PLA was synthesized from lactic acid. The oligomeric PLA was depolymerized to produce crude lactide, and then optically pure lactide was obtained from it by removing the meso lactide using water. In the lactide preparation, the temperature had a more significant effect on the optical purity of lactide. In the separation of optically pure lactide, the fraction of meso-lactide was minimized when the separation was conducted at 25 ℃. |
