Lithium chloride as catalyst for the ring-opening polymerization of lactide in the presence of hydroxyl-containing compounds

Lithium chloride was found to be an effective and biocompatible catalyst for the ring-opening polymerization of lactide in the presence of hydroxyl-containing compounds. Ethylene glycol (EG) and methyl α-D-glucopyranoside (MGlc) were used as multifunctional initiators. The polymerization was carried out at 128°C in bulk with 1% (w/w) of LiCl. Polylactide (PLA) of different molecular weights was obtained with varied molar ratios of monomer/initiator ([M]0/[I]0). The LiCl-catalyzed ring-opening polymerization was applied to the synthesis of a number of amphiphilic PLA copolymers when poly(ethylene glycol) (PEG), hydroxyethyl cellulose (HEC), and hydroxypropyl cellulose (HPC) were used as macroinitiators.