Kinetic Study of D,L-Lactide and Glycolide Homopolymerizations by Differential Scanning Calorimetry

The homopolymerizations of D,L‐lactide and glycolide catalyzed by ZnOct2 were studied by DSC. The kinetic parameters obtained are compared with those obtained from conversion data of bulk polymerizations. For the glycolide, the respective values of the calculated rate constants were quite similar. For the lactide polymerization, however, the agreement between the values obtained was not so good because the kinetics is affected by thermodynamics in the DSC experiments. As a result, the kinetics can not be studied by DSC. The degree of aggregation of the catalyst, the reaction order with respect to it, and the initiator influence were determined for glycolide homopolymerization.