Ultrasound enhances lipase-catalyzed synthesis of poly (ethylene glutarate)

The present work explores the best conditions for the enzymatic synthesis of poly (ethylene glutarate) for the first time. The start-up materials are the liquids; diethyl glutarate and ethylene glycol diacetate, without the need of addition of extra solvent. The reactions are catalyzed by lipase B from Candida antarctica immobilized on glycidyl methacrylate-ter-divinylbenzene-ter-ethylene glycol dimethacrylate at 40 °C during 18 h in water bath with mechanical stirring or 1 h in ultrasonic bath followed by 6 h in vacuum in both the cases for evaporation of ethyl acetate. The application of ultrasound significantly intensified the polyesterification reaction with reduction of the processing time from 24 to 7 h. The same degree of polymerization was obtained for the same enzyme loading in less time of reaction when using the ultrasound treatment. The degree of polymerization for long-term polyesterification was improved approximately 8-fold due to the presence of sonication during the reaction. The highest degree of polymerization achieved was 31, with a monomer conversion of 96.77%. The ultrasound treatment demonstrated to be an effective green approach to intensify the polyesterification reaction with enhanced initial kinetics and high degree of polymerization.

Report on the scientific results of the voyage of S.Y. "Scotia" during the years 1902, 1903 and 1904, under the leadership of William S. Bruce.

v. 3,pt.1-11

Expédition antarctique française (1903-1905) : commandée par le dr. Jean Charcot.

Hexactinides, Bryozoaires

Report on the scientific results of the voyage of S.Y. "Scotia" during the years 1902, 1903 and 1904, under the leadership of William S. Bruce.

v. 6,pt.1-11

Natural history.

v.4, c. 2

Meteorology ... Prepared under the superintendence of the director of the Meteorological office with the co-operation of a committee of the Royal society.

Pt.2

Report on the scientific results of the voyage of S.Y. "Scotia" during the years 1902, 1903 and 1904, under the leadership of William S. Bruce.

v. 7,pt.1-13

Natural history.

v.3

Report on the scientific results of the voyage of S.Y. "Scotia" during the years 1902, 1903 and 1904, under the leadership of William S. Bruce.

v. 4.pt.1

Natural history.

v.5, c. 2

Deuxième expédition antarctique francaise (1908-1910) / commandée par le dr. Jean Charcot.

Embryologie des Spheniscidae

Expédition antarctique française (1903-1905) : commandée par le dr. Jean Charcot.

Vers et Brachiopodes: Nemertiens, Gephyriens, Brac

Deuxième expédition antarctique francaise (1908-1910) / commandée par le dr. Jean Charcot.

Lichens

Deuxième expédition antarctique francaise (1908-1910) / commandée par le dr. Jean Charcot.

Mousses

Expédition antarctique française (1903-1905) : commandée par le dr. Jean Charcot.

Botanique: Mousses, Algues