Method to manufacture PLA using a new polymerization catalyst

The invention relates to a method for manufacturing poly lactide , comprising the steps of mixing lactide and a metal coordination compound as polymerization catalyst to obtain a reaction mixture , polymerizing the lactide in liquid phase at a temperature of at least 150° C . to form polylactide in liquid phase and allowing the polylactide to solidify , characterized in that the polymerization catalyst comprises a
metal - ligand coordination compound whereby the parent ligand answers the formula ( I ) , whereby R represents an H
atom , an aliphatic group , a halide atom or a nitro group and the metal is at least one of Zr and Hf . The invented catalysts show kinetics which is comparable to the kinetics of the known Sn - octoate catalyst