Recently, biodegradable polymers, mainly produced or synthesized from renewable resources have attracted great attention to replace petroleum-based commodity plastics owing to environmental concerns. Polylactide (PLA) is one of the promising biodegradable polymers and has a wide range of desirable properties. However, it contains intrinsic characteristics that are hard and brittle than other conventional thermoplastic polymers, and also has low elongation at break and thermal instability. Thus, this study focused mainly on flexibility enhancement of PLA by using diethyl succinate as a new environmentally-friendly aliphatic plasticizer. PLA was melt blended with the plasticizer at various contents (0-30 phr). The plasticized PLAs were characterized in terms of mechanical and thermal properties. The results showed that tensile strength and modulus of the plasticized products were decreased correspondingly with an increase in plasticizer concentration, whereas elongation at break was drastically increased up to 273% obtained at 20 phr, which is approximately 80 times higher than that of the unplasticized PLA. Moreover, glass transition temperature of modified PLAs was effectively decreased.

Keywords: biodegradable polymer, polylactide, plasticizer, flexibility