Ring-Opening Polymerization of l-Lactide to Cyclic Poly(Lactide) by Zeolitic Imidazole Framework ZIF-8 Catalyst

ChemSusChem. 2017 Nov 9;10(21):4135-4139. doi: 10.1002/cssc.201701438. Epub 2017 Oct 24.

Abstract

The catalytic activity of ZIF-8 in the ring-opening polymerization of l-lactide without solvents or cocatalysts is presented for the first time. Two different synthetic strategies have been applied for synthesizing ZIF-8, either under solvothermal condition or by spray-drying procedure. Their catalytic activities are found to be correlating with the presence of open active sites in ZIF-8 structure. The structural defects that afford active acid and basic sites are supposed to cooperatively catalyze the reaction. ZIF-8 assembled by spray-drying technique, displays a superior catalytic activity at temperature of 160 °C, leading to the formation of high molecular weight cyclic polylactide. The ZIF-8 catalysts could be recycled and reused without any significant loss of catalytic activity.

Keywords: heterogeneous catalysis; metal-organic frameworks; polymerization; structural defects; zeolites.

Publication types

  • Research Support, Non-U.S. Gov't