040132: A Reactive Extrusion Process for Formation of Biodegradable, Bioabsorbable Co-Polymers of 1,4-Dioxan-2-one and a Cyclic Ester

Current methods for producing these polymers typically result in low conversion of monomer to polymer product. Removal of the monomer is a time and cost intensive procedure.


This invention describes an approach to synthesize copolymers of 1,4-dioxan-2-one and a cyclic ester using continuous extrusion and an organometallic polymerization agent (catalyst or initiator) with good control of conversion of monomer to polymer and of molecular weights.


  • High efficiency: Continuous extrusion is a highly efficient method of polymerization.
  • Cost effective: Lower costs due to high conversion of monomer to polymer, eliminating monomer removal step. Bulk process eliminates the need for costly solvents and solvent removal steps.


This invention produces copolymers which are biodegradable and bioabsorbable. Primary uses of these polymers are in medical applications such as orthopedic surgical repair, controlled release drug delivery, wound closures, and as scaffolds for tissue growth. Major users of the technology would be those companies that supply bioabsorbable polymers to the medical use markets.

IP Protection Status

US 7361727 (issued Apr 22, 2008)
Patent Information:

For Information, Contact:

Bradley Shaw
Technology Manager
Michigan State University - Test