Isocyanate‐free Route to Starch‐graft‐Polycaprolactone via Carbonyldiimidazole (CDI)‐mediated End Group Conversion

This paper reports on the synthesis of biodegradable starch‐graft‐poly ϵ‐caprolactone (starch‐g‐PCL) in two steps. First, poly ϵ‐caprolactone (PCL) was modified on the terminal groups by using carbodiimidazole (CDI) as coupling agent. Then, the starch graft copolymers with PCL were prepared through a carbonate bond using carboimidazole function. Monofunctional and bifunctional reactive end‐group PCL terminated with carboimidazole groups were prepared and reacted with hydroxyl groups of starch. The resulting starch‐g‐PCL copolymers were characterized by FT‐IR, NMR, HR‐MAS‐NMR, DSC, MEB and XRD.