PROCESS FOR PREPARING A POLYESTER

摘要

The invention is directed to a process for preparing a polyester or copolymer containing ester functionalities, and more in particular to a process for preparing a polyester or copolymer containing ester functionalities using metal mediated ring-opening polymerization. The process of the invention comprises providing an optionally substituted lactone having a ring size of from 6 to 40 carbon atoms; and subjecting said lactone to metal mediated ring-opening polymerization using as catalyst a compound according to general formula (I) wherein - M is selected from the group consisting of A1, Cr, Mn and Co; - X and X' are independently a heteroatom; - Y and Y' are independently selected from the group consisting of O, N, S, P, C, Si, and B; - Z is selected from the group consisting of selected from the group consisting of hydrogen, borohydrides, aluminum hydrides, carbyls, silyls, hydroxide, alkoxides, aryloxides, carboxylates, carbonates, carbamates, amidos, thiolates, phosphides, and halides; - L1 and L2 are independently an organic ligand linking X and Y together and linking X' and Y' together, respectively; and - L3 is an optional organic ligand linking Y and Y' together.