The majority of the biodegradable polymers in clinical use are composed of stiff materials that exhibit limited extendibility with unsuitably high Young's modulus and low elongation at break values that make them non-optimal for various biomedical applications. Polylactide (PLA) is often used as a biomedical material because it is biodegradable, but the physical and mechanical properties of PLA need to be improved for biomedical applications. In order to improve the flexibility and strength of biodegradable PLA, various reaction conditions were studied. Urethane structure polymer materials were prepared; PLA was reacted with a small amount of methacryloyloxyethyl isocyanate (MOI) to obtain a ductile PLA with markedly improved mechanical properties. Elongation at break increased by 20 times when compared to neat PLA. Impact resistance (notched) improved 1.6 times. Thus, this modified PLA biodegradable polymer may have greater application as a biomedical material with increased mechanical properties. (C) 2010 Elsevier Ltd. All rights reserved.