Polylactic acid (PLA) is a biodegradable polymer that has been useful in various biomedical applications. High stiffness and brittleness that are characteristic of PLA must be improved to allow for more applications. Ionic liquids (ILs) are considered to be "green" alternatives to volatile organic compounds in organic synthesis, catalysis, liquid liquid extraction, polymerization, bioprocessing operations, and many other applications. In order to improve the ductility of biodegradable PLA, we incorporated two green materials, PLA and IL, to prepare green functional polymers. PLA was modified with ionic liquids (e.g. 1-methyl-3-pentylimidazolium hexafluorophosphate [MPI][PF6]) to prepare ductile PLA with markedly improved ductility. Elongation at break can be increased by 25 times when compared to neat PLA. Thus, IL modified PLA polymer may have greater application as a biomedical material with ductile mechanical properties. (C) 2012 Elsevier B.V. All rights reserved.