Controlled synthesis of star-shaped homo- and co-polymers of aliphatic polyesters

POLY 554

Ann-Christine Albertsson, aila@polymer.kth.se, Karin Odelius, odelius@polymer.kth.se, and Anna Finne-Wistrand. Fibre and Polymer Technology, School of Chemical Science and Engineering, Royal Institute of Technology, Teknikringen 56-58, SE-100 44, Stockholm, Sweden
The challenges in finding a material with the proper characteristics for a given tissue engineering application are several. One solution is improving the ability to tailor the mechanical and physical properties along with the degradation profile of aliphatic polyesters, by for example alterations in their composition and architecture. In this study, well-defined star-shaped aliphatic polyesters constituted of four arms were synthesized. As a model system, L,L-lactide and a spirocyclic tin initiator was chosen and the affect of the solvent, temperature and monomer-to-initiator ratio on the number average molecular weight, the molecular weight distribution and the conversion of the polymers was shown. Consecutively, we proved that well-defined star-shaped block copolymers composed of 1,5-dioxepan-2-one and L,L-lactide with narrow molecular weight distributions and controlled block lengths can be synthesized using this system.