Tailored mechanical properties and degradability of polyesters by controlled molecular architecture

Advanced molecular architectures have been used as a tool for tailoring the mechanical properties and the degradation process of polymers for specific applications. Crosslinked poly(1,5-dioxepan-2-one), random poly(1,5-dioxepan-2-one-co-L-lactide), triblock poly(L-lactide-b-1,5-dioxepan-2-one-b-L-lactide) and triblock poly(e-caprolactone-b-1,5-dioxepan-2-one-b-e-caprolactone) have been synthesized and their thermal and mechanical properties as well as degradation times and degradation products have been characterized and compared. The stress at break of the synthesized polymers ranged from 4 MPa to 55 MPa and the elongation at break from 25% to 1200%. The degradation time varied from 70 days up to 360 days. These polymers are suitable as films or microspheres for controlled drug delivery or as temporary tissue replacements e.g. for tendons or nerve guides.