MELT-STABLE LACTIDE POLYMER COMPOSITION AND PROCESS FOR MANUFACTURE THEREOF

摘要

A lactide polymer composition combining compositional and purity limitations and catalyst optimization or addition of stabilizing agents resulting in a melt-stable polymer is disclosed. The melt-stable lactide polymer comprises a mixture of polylactide material having a number average molecular weight of at least about 10,000, residual lactide in concentration of less than about 2% and water in a concentration no greater than 1000 parts-per-million. A stabilizing agent in an amount sufficient to reduce depolymerization of the lactide polymer during melt-processing or alternatively, control of catalyst level at a molar ratio of monomer to catalyst greater than 3000:1 is also included in the melt-stable composition. A process for manufacture of a melt-stable lactide polymer composition includes polymerizing a lactide mixture and adding stabilizing agents sufficient to reduce depolymerization of the polylactide during melt-processing, followed by devolatilizing the polylactide to remove monomer and water.