Biodegradable poly(ethylene oxide)/poly(ε-caprolactone) multiblock copolymers

A series of poly(ethylene oxide) (PEO)/poly(εcaprolactone) (PCL) containing biodegradable poly(ether ester urethane)s, covering a wide range of compositions, were synthesized and characterized. The synthesis consisted of a two-step process. During the first step, the ring-opening reaction of ε-caprolactone was carried out, initiated by the hydroxyl terminal groups of the PEO chain. The second step involved the chain extension of these PCL-PEO-PCL trimers with hexamethylene diisocyanate. By varying either the ethylene oxide/ε-caprolactone ratio or the length of both segments, we obtained a series of polymers having different morphologies and displaying a broad range of properties.