Hydrolysis of poly(l-lactic acid) using microwave irradiation
| Autor: | Hitomi Ohara, Yoshie Shimamoto, Yuta Nakatsuchi, Koichi Hirao |
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| Rok vydání: | 2010 |
| Předmět: |
Poly l lactic acid
Materials science Polymers and Plastics Condensed Matter Physics Lactic acid Hydrolysis chemistry.chemical_compound Reaction temperature chemistry Mechanics of Materials Yield (chemistry) Microwave irradiation Polymer chemistry Materials Chemistry Enantiomeric excess Saturation (chemistry) Nuclear chemistry |
| Zdroj: | Polymer Degradation and Stability. 95:86-88 |
| ISSN: | 0141-3910 |
| DOI: | 10.1016/j.polymdegradstab.2009.10.003 |
| Popis: | Poly( l -lactic acid) (PLLA) was hydrolyzed using microwave irradiation, and yields of the resultant lactic acid and reaction time were compared with those obtained by conventional heating. In both cases, the reaction temperature was maintained at 170 °C and the weight ratio of PLLA:H2O was 3:1. Under conventional heating, the lactic acid yield reached saturation after 800 min at 45%, whereas only 120 min was required to reach the same yield level under microwave irradiation. The optical purity under conventional heating decreased with hydrolysis of the PLLA and dropped to 94%ee when the lactic acid yield reached at 45%. Under microwave irradiation, however, the optical purity decreased only after the equilibrium state of hydrolysis was attained. Therefore, to maintain the optical purity at 98%ee, it was necessary to stop microwave irradiation when the lactic acid yield reached 45%. |
| Databáze: | OpenAIRE |
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